Search the Community

Showing results for tags 'ufh'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • BuildHub Guide: Information about the site : Introduce Yourself
    • About
    • Introduce Yourself
  • Build Design, Planning, Finance and Legal
    • Building Plots, Land & Renovation Properties
    • Design & Architecture
    • Funding, Finance & Tax
    • Insurance, Legal and Warranties
  • House Construction & Structural Issues
    • House Construction
    • Conversions & Extensions
    • Roofing & Lofts
    • Structural Works, Foundations & Demolition
    • Insulation & Ventilation
    • Landscaping & Outdoor Buildings
    • Damp & Infestation
  • Building Trades
    • Plumbing & Heating
    • Bricklaying, Plastering, Concrete, Blocks & Rendering
    • Joinery, Windows & Doors
    • Floors & Flooring
    • Electrics, Lighting & Home Security
    • Decorating & Tiling
    • Kitchens & Bathrooms
    • Building Materials
  • Environmental, Alternative & Green Building Methods
  • Self Build & DIY: General
  • Self Build Regional Groups


  • Salamander Cottage
  • The House At Mill Orchard
  • An Orkney Build (in ICF)
  • The House at the Bottom of the Garden
  • Hawthorn House
  • Rose Lane re-build
  • East Kent Self Build
  • Wee Hoose on the Croft
  • God is in the Details
  • Tennentslager
  • Kentish RenoExtension
  • Scooby Cottage renovation.
  • The Seasalter Sharp House
  • sussexlogs
  • Sips and stones may break my bones...
  • Our Journey North of the Border
  • Construction in Cornwall
  • The Fun Irish (House)
  • A house! A house! My kingdom for a house!
  • South Devon Self Build
  • Lucy Murray
  • Coffee Towers
  • caliwag
  • caliwag
  • Blackmore House
  • A woodland house
  • Druim nan Darach
  • Escarpment to the countryside
  • Recoveringbuilder
  • Netherwood lakes
  • Kingseat
  • Mr and Mrs Triassics New Home
  • Yaffles
  • Wedding Cake Re-build
  • Clancutt Lodge
  • Self-Build in Shropshire
  • South coast ICF build
  • 5 (2 adults, 3 dogs) go building in Dorset
  • Hillcroft
  • Self Build NE Scotland
  • Timber Portal Frame - but stick built
  • Self Building two in North Wiltshire
  • 1970s Chalet-style house renovation
  • Under the Chestnut Tree
  • The Larch House
  • Building in a woodland on the Isle of Wight
  • Back on the self-build waggon...
  • Gardening in the Lockdown
  • The BuildHub Gardening Blog
  • West Sussex Forever Home
  • Testing
  • Canalside Bungalow Renovation
  • Holywood Passive ICF Build
  • Finchampstead Passivhaus
  • Albaston self-build
  • Little Stud Barn
  • East Cornwall Low Energy build
  • Scottish SIPS build
  • Gus Potter
  • Garden Escape

Find results in...

Find results that contain...

Date Created

  • Start


Last Updated

  • Start


Filter by number of...


  • Start



About Me


Found 112 results

  1. Hi My first post here - was pointed in this direction by a friend of mine. After months of research (feels like months) I think I have come to a conclusion on which UFH system and I just needed some support on ensuring I had made a right decision (otherwise my wife and kids will kill me in the middle of winter). Background I am doing a renovation project of the ground floor of my house - 95m2. It is a 1930s semi - whole place is being gutted and an extension going in. The current flooring is timber joists and in a bad condition and has no insulation. So first job will be to rip up the flooring and add 100mm of Kingspan or Celotex in between the joists. Now the complexity of which UFH system to go for. I have boiled down to 2 options: Option1: TorFloor by Omnie - I can use these boards as the structural floor, I am hoping a competent plumber can install this and I can get a 9mm plyboard on top and finish the floor with LVT like Karndean. The height build up is 35mm (22m board, 9mm ply, 4mm Karndean). So the build up is pretty similar to what I have with the existing boards and underlay and carpet Option2: Install a pannelling and screed system (like Nuheat or Profix). With this system I would put some 6mm T&G plywood over the top of the joists, put down the castellanated panels, pipes would go in and screed on top. As I cant put Karndean straight on top of the screed, i would need to finish with 6mm ply and Karndean finish on top. So the build up is 80-85mm (6mm ply, 15-20mm panels depending on system, 50mm screed, 6mm ply, 4mm karndean). It is not clear how much screed I need as some systems are different. I am hoping I have described the above scenarios correctly - I am not a seasoned DIYer so all the research has been mind blowing !!!. In conclusion I am tending to go for the Omnie Torfloor system - number of reasons - floor build up is lower and its £3k cheaper. However what I dont know is the output and difference between a screed system and an overlay system. Any opinions on my conclusions?? Please tell me if I have got this one wrong !! Ideally I need a fairly quick heat up and a fairly good output - kids and mrs moan in the middle of summer of how cold it is !!! Thanks for reading
  2. Morning everyone Our house build is progressing nicely and we have recently had the ufh installed both downstairs in the traditional way (stapled to insulation, screed on top) and also on the first floor, in 25mm in between batons etc. We then screwed and glued 6mm ply to the batons to protect the screed and provide a sound surface for tiling/flooring. Although the dry screed was swept and hoovered before the ply was laid The problem we are now finding is a 'crunching' noise when you walk around, between the ply and the screed. Has anyone who has used this system experienced similar problems? Does it go in time? I don't want to get to a position of getting carpets etc down and still hearing the annoying crunch. Any advice/experience gratefully received. Many thanks
  3. Right, so following on from my blog entry here where I discuss using Willis heaters to heat up my UFH ( ) I'd initially tested them earlier in the year when I'd set them up and then only in the past 4wks really started to use them for some evening heat in the house and they did their job pretty well (not turned on all the loops yet as there are some rooms that aren't completed yet (north colder part of house). So only switched them on manually for say 2-3 hours each day. Yesterday one of the heaters started 'making noises' that he was not happy, so I switched that one off and left the other one to run. Then today the other one also decided it was not happy. Video below, with aforementioned Willis...'making noises'. 20201112_164008_001.mp4 To me it sounds like a kettle that's trying to boil/simmer with not enough water. I'm suspecting it's scaled up already in this short time. There's no heat coming from the outlet pipes at all and the heaters themselves don't feel warm either. I still have pressure (1.5 bar) so I don't think I have a leak anywhere and no water in pipes. The manual bleed valves indicate there's water in the manifold at least. Any other ideas before I start dismantling the buggers as there's at least 4 compressions I have to bugger about with which were a pain to seal initially? Resident willis heater experts @Nickfromwales, @TerryE ? :-) TIA!
  4. Hi community, Over the last 2 weeks I've been trying to take in lots of info regarding ashp since having one installed in a new build, thanks so much to all the people that contribute with their esteemed knowledge, much of it on here is well above my basic understanding and it seems there are a myriad of things to consider when trying to optimise the systems. Bit of background, 186m2 timber frame kit from a company called scotframe, as a non builder this seemed like a means of eradicating some of the problems with builders as it progressed. Product has been good aside the nordan windows and doors imo, the erectors not so good, wish I'd hired a chippy with lots of new build experience to keep and eye on them but I am where I am now.. if anyone has questions about scotframe always happy to share my thoughts and experiences. Installed I have an ecodan 8.5kw system with ufh downstairs dfor heating and DHW. no buffer tank just the ecodan cylinder with 6 room stats downstairs. Vent axia sentinel mvhr yet to be commissioned / balanced. 75mm screed on top of 140mm celotex. pipe spacings at 125mm (mostly anyway). Been running now for 2 weeks, the house is at a comfortable temp downstairs, 17 deg, and that what's the stats are set at, not lived in yet but in this cold weather seems heating will be needed upstairs with points for electric heaters of some sort ready for the future. After lots of reading on here I've decide to run the ufh at a low flow temp, presently 29 degrees and run it continuously aside from peak pricing times with octopus agile.. . The house seems to hold heat reasonably well but until I move in to a semi building site in around 6 weeks I wont know exactly how it performs. Whilst the heat pump installer / plumber was a lovely chap and had a love for making perfect copper piping I'm not entirely sure how technical he is when it comes to these systems. I have lots of questions but the thing that's initially baffling me is on the control panel for the heat pump when the ufh is running its shows the flow and return temps are very similar circa only 1 or 2 degree loss between the two. From reading on here that seems far too narrow so the lovely heat the pump is generating heat but returning the majority of it . If someone could help me understand the impact this will be having on the heat pump / efficiency and then how I would go about increasing this difference that would be appreciated. The installer left all flow rates at 2.5 which was nothing like the ufh design I've referred back to, so a few days back I reduced these to what the design recommended, but this hasnt affected these flow and return temps which I assumed it would have. As said for many on here with knowledge in this area it may well be like pulling teeth trying to get me to understand what's going on but I'm game for the challenge Thanks.
  5. There have been so many little problems Ive asked for a break with the builders so I can do more research. Do I recall people discussing that UFH and ASHP might not be a great idea for a rental property? I'm not planning to rent the stables right now but its not impossible in the future. Is that because of the PITA factor and the chance of poor installation/incorrect sizing etc etc
  6. I moved into a 4-bed dormer bungalow (176m2) last summer that had just been gutted, extended and completely renovated, including ASHP for the DHW and UFH. The ASHP is a Nibe F2040-8 (8kW). The UFH is in screed downstairs and on aluminium trays in the suspended floor upstairs (both with 200mm pipe spacing). There is no buffer tank, although there is a volumizer unit. Room temps are set to 18C for bedrooms and 20C for the kitchen/lounge etc (no night-time setback). The UFH downstairs can maintain target room temps with a flow temp of 25-35C. However, the upstairs seems to need a higher flow temp of ~45C to maintain target room temps. The problem with this is that when the outside temp falls below 5C, the ASHP continually defrosts and is unable to deliver a flow temperature >30C (i.e. the opposite of the intended weather effect compensation!). I have attached some screenshots of plots from my Nibe Uplink – the first is when the outdoor temp was ~10C, which shows the flow and return temps oscillating around the target flow temp (which is what I would expect to see) and the other shows the same plot when the outdoor temp is ~2C. In the latter plot, the pump is defrosting so frequently that the flow temp never achieves its target, resulting in high electricity consumption (>£200 p/m), a really noisy pump, angry neighbours, and room temps <18C upstairs. The installer is refusing to investigate this problem and Nibe will only interact with installers. Q: is the impact of the defrosting cycles what you would expect for an ASHP at <10C? If not, any thoughts on the underlying cause – insufficient pump size? Lack of a buffer tank in the design? Anything else you can think of that might cause this…? Looking forward to your expert input and happy to provide any additional details that might be helpful.
  7. Hi all, We are getting closer to having our UFH pipes laid on the ground floor (in 50 mm liquid screed). My design is as shown in the attached image (150mm centres) , however have been told that its not the best way of having it and a spiral design would be better and give more even heating and less chance of any cracks. Is that right or is my design perfectly adequate? All the runs are less than 80m long, I didn't want to go more than 150mm on the centres as I wanted to improve heat up times on the system and the plan was to run the UFH at as low temperature as possible so that the boiler is condensation mode all the time while the heating is on (If anyone has any further information on system design in that respect it would be much appreciated). Thanks
  8. £820 for the quarter. I appreciate it is winter and the pump works harder but I wasn't expecting that. Lighting wise I have the open fitted with spots (only since Dec) and appliance wise (again since Dec) couple of ovens, hob, 2x F/F and a dishwasher which leads me to think the UFH is the culprit. I have looked at the UFH pump (a wilo 25/6) and found that the setting on this was not correct for the UFH so have change the profile as per the manual but couldn't work out what speed to set so went for the medium. I only have 5 zones from the 10 zone manifold active ( four controlled by a neostat) and one zone (bedroom)that is on but with the little TRV so comes on and off with the open plan. area. Flow rates are set to 1.5ish l/m. I have a 40l buffer but have found that when the heating comes on this drains and before the required room temp is reached it empties and I am pumping cold water around the system. None of the floors are warm (which the wife is most annoyed by) although the house does not feel cold. The UFH pipes etc was installed by the screed company and the water works and pump by a reputable plumbers. I connected the flow and return to the cylinder and when the commissioned that they said there was no issues with the plumbing between the two. I would have called someone out to have a look but I am skint now...any ideas please? thanks in advance
  9. How do you decide what speed to set the pump which is on the manifold? The pump which is inside the heat pump controls itself although you can alter the flow rate. At the moment it is running on speed three but that is how it was when it was turned on. TIA
  10. I'm in the early stages of the refurb of a 1917 property in Kent. The rough downstairs floorplan is below - The floor is a real hotchpotch of suspended floor (45% - Green), Previous extension concrete floor ( 35% - Yellow) and New proposed extension (Orange 20%). The current EPC is a horrible 23 and we're looking at using a combination of internal and external insulation to improve this. This may be an opportunity to seal the house (replacing floorboards?) Trying to bring all the potentially different technologies and solutions together is a challenge and every choice seems to lead to a particular specialist supplier that may have a particular axe to grind/product to sell. There is a wealth of knowledge and experience on this forum that I am very glad that I have found. Regards Tet
  11. Finally got the heat pump up and running. After clearing the air locks the system seems ok (?) but just need some reassurance that it is working. The house is obviously very cold (10 degrees) so it is going to take some time to warm up. How long does it take to see some improvement as it went up 1/2 degrees but I also turned on my mvhr today so a few things changed? What have people set the water temp for the ufh? House size is approx 26 x 9 internal floor area and is all ufh on a Passive slab so I know it is going to take a while. When I initially got it running the buffer tank heated up quickly but the blending valve was not adjusted so as soon as i altered that the heated water went into the ufh pipes and all the heat just dissipated so I guess I am after as much info regarding the first time of turning on the ufh and the running of there after, please!! I know you have to warm the slab up slowly but it could'nt get any slower but I am comparing it to rads as I have never experienced wet ufh before. TIA
  12. I've read various threads and views and back and forth and done some calculations based on information I have found here and of course from the very helpful spreadsheets provided by our friend @Jeremy Harris. I had pretty much decided ages ago I would get an 8.5kW Ecodan, which might go up to an 11.2kW ecodan unit. However I have not really advanced it beyond basic assumptions, what others done and some quick back of the fag packet calcs. I'm about to start foundations shortly hence, need to firm up on the UFH design for the in slab pipework and would appreciate some sense checking/ a wee nod that it seems ok. Build is SIPS with Kore insulated foundation, aiming for high levels of airtightness but not near PH (basically as best as I can get it without major hassle), Vent Axia Sentinel MVHR. ASHP which does UFH and DHW (UVC 3-400L tank). Secondary heat source of Log burner (I'm aware it's overkill likely - but I have 2 acres of woods, vaulted ceiling and need a backup in the event power ever went out). I would like to map out the steps in layman's terms to ensure they are right and I have followed it correctly from what I have read, then hopefully the thread can then be followed by others. Step 1 - Heat loss calculation: So I completed the heat loss calculator - see attached. I have a few checks to do on areas and might make minor adjustments but near as dammit it's close enough. I have added the OAT values for my local area (West Scotland, south of Glasgow) from the MET office. Now do I basically just use the 'Total daily heat loss power for average OAT (W)' value to find the maximum based on historical data and that defines the minimum amount of heating system required such below: which seems 3.6kW heat loss for January. The simply - I select a heating system which can supply this amount of heat as a minimum (ignore losses for now). So just simply selecting an 8.5kW unit would do the job easy? Step 2 - UFH design So Having found out the maximum heat loss above (3602W) then we can just plug this into the Heat loss and UFH calculator, which I have also attached. And provides the following output. So essentially, going on bare minimum I would need an UFH system which provides 27.7W/m^2 , based on 130m^2 of floor - so essentially if I don't use some slab area then I need to compensate and adjust the calc. Step 3 - UFH loop spacing So I know the total heat loss, I know how much heat input I have to supply per m^2 if I cover the whole area of 130m^2. So I get loopcad, then draw the circuits. Aiming for counter flow circuits as they provide the best option for even heat distribution, keeping circuits less than 100m in length. Now this is where I get a little lost, I have a figure of 27.7W/m^2 for the whole area to get my required heat input, however how do I correlate that with loopcad and also deciding what my spacing should be?! I have seen @PeterW mention quite a few times about the the spacing had to be adjusted but I am struggling to find the route here to confirm easily what it should be. My loopcad drawing (I've attached my current draft) showing for example 105W/m^2 in my living room, but I'm not sure how this should read in relation to my calculated figure. I'm pretty sure I'll need 200mm centres, but I'd like to ensure that was right. I've some adjustments to make to my circuits, but it's not far away. I was finding that the auto generate function for pipework isn't ideal but it works ok. The garage can be ignored - I ma installing pipework in there pre-empting possible future conversion of that area and hence pipe is cheap, so why not add it now. The manifold will go below the stairs - seems to make sense to me, I have a plant room directly adjacent and was going to put it in there but seemed better to get it out of there as I will have lots of ducts and this would clutter that up. Is it ok to run underneath the stairs? I assume I just have to tell the Joiners not to fit the stairs to the floor with big screws?! Step 4 - Zones I am only having downstairs heating, so it is a single manifold. I would prefer as few zones as possible, but a single zone wont work. I was thinking I can have two /possibly three. Zone 1 - Main family room area Zone 2 - Everywhere else excluding shower room and garage Zone 3 - Shower room Zone 4 - Garage (permanently isolated at the moment. I assume you can have multiple zones on a manifold, and can just split them up by using salus actuators?. So a single thermostat for family room can control three loops (each with an acutator) in that room? and so forth?. It's a long post , and actually I wasn't going to talk about zones but thought it was worth adding in. Thanks. Heat loss calculator - SuperJohnG.xls.xlsx Floor heat loss and UFH calculator - SuperJg.xls.xlsx Looopcad - SuperJohnG.PDF
  13. Hi, I had a mid life crisis and decided to rip out the central heating system and install underfloor heating 😀 The project isn't finished yet, but most of the rooms now have heating. This is a retrofit system using overboards with pipes laid in them at 150mm centres. I have a couple of questions that I'd like to get a better understanding of (bit late, I know!). Q1 - Efficient UFH temperature I don't know much about thermal dynamics, so hypothetically, if I have a system that loses 1 degree per hour when the heating is off, and it takes 1 hour to increase the temperature by 1 degree when it is on, would it be more efficient to let the heating go from 21 to 18 over 3 hours and then from 18 to 21 over another 3 hours, or would it be better to go from 21 to 20 and then back to 21 every two hours, or doesn't it make a difference? The reason for this question is that I'm thinking of leaving it polling constantly between 20 and 21 degrees. Q2 - UFH max floor temperature dilemma I currently have the manifold set to 42 degrees. This is taking a lot of time to get up to room temperature (5-8 hours, and it's not even winter yet!). The problem is, if I set the temperature any higher then the floor gets above 27 degrees (tested with an infrared thermometer, although this may be inaccurate?), and as most of the house is laminate, I believe this is not a good idea. I did think about installing floor probes, but I figured that once the floor got above 27 degrees, the heating would cut off until the floor temperature dropped below 27, which may protect the floor, but would defeat the object of trying to heat the house, albeit heat would still be coming from the floor? I also assume that once the temperature drops outside in the winter, the floor won't reach 27 unless I increase the output temperature from the manifold, so it will be a juggling act through the seasons? As you can see, I didn't think this through first 😂 and I hope I haven't left out any vital information in these questions. Still glad I did it though! Regards
  14. Hello guys, I have searched google but I could not find an answer in my attempts to find out why the red cap flow meters of UFH systems are always fixed on top of the manifold, and the actuators are placed below. Could anyone explain, is there a specific reason why is it so? Is it allowed to fix them contrary, and would that have any negative consequence?? Thank you for your answers.
  15. Hi there, I've a 125m2 extension being erected next year with a pretty basic floor slab planned. Floor covering 65mm Screed UFH Pipwork 150mm PIR insulation 100mm c35 concrete with mesh Whilst looking at the overall prices of each piece of work there's a couple of questions that have come up would it beneficial to change the floor structure to incorporate circa 250mm of eps insulation under the concrete slab, instead of the 150mm pir above slab. And whilst I am at it, possible to incorporate the Under floor heating pipework into the slab, as opposed to having the pipework in a screed on top of the slab? The reason for looking at this is to save time and money. The 250mm of eps insulation has similar u value to 150mm pir, whilst being cheaper - circa 1k at the moment, but there is another price increase on pir due in February. If I incorporated the pipework into the slab, I could save circa 4k for the screed work post panel installation, but it would also mean I could crack on with the studwork immediately after the kit erection as opposed to laying pipework and ordering in self levelling screed. any thoughts/drawbacks?
  16. Hi all, Trying to figure out the best option for ufh in our new extention incorporating existing kitchen area etc. (I’ll attach the plans) I can’t figure out, A: is it best to clip onto foilbacked board in between joist and biscuit screed/cover with chipboard? B: lay routed panel boards and tile straight on top? I don’t really like the idea of tiling straight on top of the pipe as In “B” but will I feel the benefit and will we get enough heat from option “A”? the boiler is going into the utility, would like two zones, one for the main living space/kitchen and the other for the shower room. it’s a mine field, any help and guidance would be much appreciated. Also any other systems/options that would work? Best, Keith. GROUND FLOOR.pdf STRUCTURE 1.pdf
  17. I seem to have what must be a common problem when using underfloor heating with a boiler however I haven’t managed to find a standard solution online. The boiler cycles at a high frequency due to the difference in boiler power compared to what the underfloor heating manifold will accept. Setup (underfloor heating recently added by local plumber) – see image below Worcester Greenstar Highflow 440CDI combi boiler (Central heating power of ~29kW down to ~7.6kW) Radiators upstairs with separate thermostat and actuated valve on the CH flow. Underfloor heating downstairs with separate thermostat and actuated valve on the CH flow. Manifold including recirculation pump and mixer valve to maintain the inlet manifold temperature at ~40C. " class="bbCodeImage LbImage" alt="" data-url="http://<a href=""><img src="" alt="UFH-current" border="0"></a>" /> Issue The Combi boiler cannot modulate low enough when running the underfloor heating on it’s own therefore it cycles frequently on and off. At a high level, The thermostatic valve on the underfloor heating manifold gets close to the required temperature and throttles flow from the boiler. Boiler flow then bypasses the manifold through the pressure relief circuit and causes the boiler flame to turn off. The flow temperature drops The thermostatic valve on the underfloor heating manifold then starts to open because it’s not getting heat, pulling in cool flow and opening more and more. The boiler restarts when it’s anti cycling timer or temperature limits have been reached and quickly exceeds the underfloor heating thermostatic control valve temperature so the process restarts. If the anti cycle timer is put to it’s minimum of 1 minute, the boiler will run for 1 minute and turn off for one minute (the run time will further reduce when the underfloor heating gets up to temperature). At this frequency the flow temperature remains above the temperature setting of the underfloor heating thermostatic valve so the underfloor is happy. I assume that this boiler operation isn’t efficient and I doubt it’s doing the boiler any favours? When the radiators are operated concurrently with the underfloor heating the CH flow temperature remain stable and the system works nicely. Variables currently available in the system Boiler cycle time or temperature limit, currently 1 minute – If this is increased above 1 minute the underfloor manifold pulls in low temperature water as it cycles and therefore takes a long time to heat up. CH flow temperature, currently 60C – If this is increased it takes a little longer for the boiler to achieve the temperature however an increase of 10C only added 25s to the cycle time (by the time the high temperatures are achieved the boiler is mostly short circuiting around the bypass). Boiler pump speed, currently set to three – Assume a reduction would result in higher temperatures (lower flowrate with the same burner rate?) may also impact on the boiler/radiator operation? Boiler pump operation modes – Don’t know enough Underfloor heating pump speed, currently set to three – Don’t think this will have a significant affect. Underfloor heating thermostatic valve, currently 40C – Increasing this temperature risks overheating the engineered wood flooring. Next steps – help please! Is it a problem to leave the boiler cycling so frequently (1 min on then 1 min off)? Can any of the existing settings be adjusted to help? If current operation is a problem the only significant improvement I can think of is to add thermal mass between the boiler and underfloor heating manifold as follows (see image), any tips on these or is there a better alternative? a. Add pressurised tank (are these referred to as heat banks/or thermal stores?) upstream of the underfloor heating bypass loop. b. Draw the underfloor heating flow through the heat store in the boiler. This is the wild card option and I don’t like it because a connection would need to be made within the boiler (although it is accessible) and there may be an unforeseen impact on the hot water supply. I’ve mentioned it because it wouldn’t require another tank to locate, continually heat or pay for! " class="bbCodeImage LbImage" alt="" data-url="http://<a href=""><img src="" alt="UFH-options" border="0"></a>" />
  18. I want to lay underfloor heating but also create a firm feel underfoot that doesn’t transfer footstep impact sound below. TorBoard RdB looks like it might be the perfect answer, though it’s pricy. Does anybody have experience with this ufh board product?
  19. Converting a 3 bed very dilapidated 1930s semi into a 4.5 bed modern home. EVERYTHING is being gutted except the joists. Quotes are way over budget, particularly for the underfloor heating. I had specified wet underfloor heating throughout all three floors of the house (ground = 800 sqft, first = 750 sq ft and loft = 450 sqft), with the ground being imbedded into screed and the first and second floors being laid within some high performance extruded polystyrene boards made by Cellecta called XFLO. XFLO is quite expensive, about £26 a square metre, but the reason I had specified them is that they provide good insulation to make sure the heat goes up, are CNC drilled by Cellecta to meet any pipe layout requirements we specify and also feel quite firm underfoot. The other advantage of the XFLO is that you can lay the finished floor directly onto it. Underneath those XFLO boards, I had specified a 6mm dense rubber matting (which comes as a 10m by 1m rolled product, so pretty easy and quick to lay) to absorb impact sound, and underneath that 18mm tongue and groove ply which is nailed directly onto the joists (whereas the rubber and XFLO are just floating). In between the joists I was going to have mineral wool to mute airborne sound travel, and underneath the joists I was going to have the ceiling attached using resilient bars (with market name "Genie clips") to isolate the ceiling from the joists to further prevent sound transmission. The whole system is to be zoned as 9 zones, including one zone for the 3 towel radiators (which will be the only radiators in the house, one for each bathroom), although I'm going to provide Tado thermostats, one for each of the 8 UFH zones and a Tado smart valve for each of the towel radiators. One builder has quoted about £25k plus VAT for all of the above, and the other about £28k plus VAT. These quotes don't include the thermostats (I'm providing those). When I have challenged each of them on why this is so expensive (I was expecting about half the cost) they have said different things. The first builder has said that I could save £2,500 to £3,000 money by losing UFH in the loft and in most of the first floor, and instead having radiators there. The second builder doesn't agree that would save any money and is also trying to respect our reasons for having UFH. Instead he just thinks the system I've specified for the first and second floor is overkill and that I could make two changes which would save about £4k in labour: First, instead of 18mm ply plus 6mm rubber matting plus the XFLO boards (which are about 28mm thick) I should just lay a product sold by theunderfloorheating store calledProWarm ProFloor 22mm pre-routed chipboard. I've looked this up and I see the benefit. Like the XFLO boards, you attach it directly to the joists and it comes routed (though with standard not bespoke routing) and enables you to fix the finished floor directly. It costs roughly the same as the XLFO, but it saves the builder the trouble of having to lay the rubber matting and the ply, so the saving is in the cost of the matting (£6 per sq metre), the ply (about £14 a sq metre) and the labour to fit those two layers. Second, he says that in the bathrooms, I should just lay electric UFH rather than wet. He accepts it's dearer to run, but he says I can have smart timers on it to make sure I only have it on when needed and as there will be wet towel rails in there, I really won't use it that often. I think I'm willing to accept his second point and fir the electric UFH in the bathrooms, but I'm concerned about the disadvantages of the first point, which I see as follows: 1) I lose the impact sound protection provided by the 6mm rubber - is this such a big deal given I have an isolated ceiling and the mineral wool between the joists? If so, can anyone think of a way of combining a fairly cheap but effective sound impact layer with the 22mm pre-routed chipboard? It would only ever be my kids running around, so impact sound is not a major issue, but I want some protection. 2) Chipboard is not as durable or as strong as ply. Although both will feel similar at the outset of their lifespan, what will they feel like in 12 years time? I plan to be at the property for 12 years at least, but hopefully longer and I don't like springy floors. 3) no bespoke pipe channels like Cellecta offer with XFLO. But is this overkill? Maybe I don't need bespoke pipe layouts. Builder says that the 22mm pre-routed chipboard just has channels at 200mm pipe centres and that is a standard construction for first and second floors. Although most of the rear of the house is being extended, so it will have insulated cavity walls, and the loft will also be well insulated, the rest of the house has no cavity walls. Keen to hear your thoughts on the above. Thanks for your time!!!
  20. I have finally come to the conclusion that we are going to fit an ASHP and cylinder to our property. Over the years we have been drawn to the Sunamp, Sunamp and Willis heater courtesy of @TerryE but with the recent problems encountered and the uncertainty of how the system works if/when you have a problem does not appeal to us (Apologise to all those Sunamp owners out there). So having chosen ASHP it brings with it the problem of designing/installing the system and even though I have plumbed houses and fitted central heating systems the thought of this seems quite daunting.I have never fitted a cylinder before so this in itself is new territory so I am appealing to people who have done this themselves @joe90 , @ProDavefor any guidance you can pass on to me and may be some more help from @Nickfromwales and @PeterWif you can spare the time. I am struggling to get anybody locally who can just fit this low KW ASHP with cylinder without wanting to double the capacity, have it interact with the space station for telemetry and spend a whole week on fancy control systems. I have looked at the plug n play systems from the likes of LG and Samsung which would be very easy (ish ) to set up but would cost quite a bit more. I know I need an inverter in the ASHP and a blending valve(!) now so you can see I need quite a bit of advice to be able to understand the system and what I require. The house is Passive so will be minimum heating and I intend to keep the DHW temp low like Joe and Dave so I am trying to give you as much info to help with your advice hopefully. I know people have bought their cylinders from Telford but not sure what cylinder to buy? We will be doing solar PV at some point just not sure when. @joe90has mentioned having a buffer tank but he is not sure whether he actually needed it although he has his immersion in this tank I know you can have an immersion in the main cylinder and if I had a Willis heater as an immersion heater this could double up as a stand by if I ever have ASHP problems but how does this all connect together!! Hope you understand my dilemma and hope you can help me design and understand my DHW and UFH system from the start to the finish!!
  21. To those who commented on our GRP, this is not an update. The next installment to that will hopefully be at the end of next week when the crap roof will be off and a proper company coming in to sort after we insisted on an insurance backed guarantee. I shall update then, watch this space! Flat roof aside..... All our new extension had insulation laid and our existing flooring excavated for insulation too. We had the UFH pipes laid and there was A LOT. And then screed laid which is suprisingly even and flat using TG Cemfloor – a liquid self-levelling screed. Needless to say they did a better job of this than the roof. And part of the in roof solar frames have also gone up. Our builders found these up the loft when taking down the old ceilings. Unfortunately empty! Someone had a good party 😉
  22. Good evening all, I was after some advice please. We have an underfloor heating system installed with 8 zones. We are finding it takes quite a long time to heat under on certain zones. What operating pressure should the system be at? Ours is currently set to 2 bar? We are finding that front room is colder than the other rooms, the UFH is installed under floorboards in the insulation boards supplied, ontop of the floorboards we have tiles and wooden flooring. Is this right? Will the heat travel through this many layers? This is what was recommended at the time? Also what should the pump setting be set at? There are serval settings which can be selected from the front of the valve? Without leaving the UFH on all day being controlled by the thermostats it does take quite a long time to heat up? I’ll forward on the plans and the photos of you could get back to me that would be great? Cheers Ash.
  23. Hi, We have recently had wet UFH installed by a professional - three loops, but acting as a single zone with a single thermometer. We noticed that the flow meters showed no flow and despite the thermostat being set to 30'C, the floor didn't seem to heat evenly or as hot as we would have expected. Apologies I have little plumbing experience however started researching and I have some concerns over how it's been plumbed in. I had understood that a UFH manifest should have a flow block and a return block. I presume water should be pumped from the flow block (where the flow meters are) through the UFH underfloor piping and back to the return block where the actuators are. Therefore I assume that normally the pipes connected to the flow block should be warmer than the return pipes. In our set up, we normally see the opposite - the return end of the pipes get hot first and stay hotter than the flow end of the pipes. Also weirdly, if we turn the mixer thermostat to as hot as it will go, and then turn the pump to minimum, we see flow registered. If we increase the pump speed, the flow registered by. the flow meters decreases So it feels to me that something or several things are reversed and that we're actually pumping water the wrong way round (would flow meters register a reverse flow?). In other google images of similar setups, I see the output of the mixer plumbed into the flow block, whereas ours is plumbed into the pump which is then plumbed into the return block. I would be really grateful if someone could look at the attached photos and let me know your thoughts - am I right that the flow is reversed and is there any reason why the plumber would have done this (he's not replying to our messages at the moment which also concerns me!). Thanks in advance
  24. Trying to get my head around what I need to install UFH and four towel radiators and three small aluminium panel radiators. Been in touch with Wunda, asked about Wilo pumps and they said no longer supply, asked about a lower temp range blending valve and they said 35 is the min. So I started looking around at other suppliers. Came across Emmetti, and they do a mixed rail manifold M3V that has a hot side for rads and a cool side for UFH. Or is this just overcomplicating matters. Has anyone used their weather comp controls? They have a modulating blending valve connected to their weather comp, as I am feeding all the heating from a buffer tank, I presume I cannot weather comp the boiler, as it only gets a call for heat from the buffer stat, or the DHW stat in the main tank. My UFH is sitting in 55mm Cemfloor screed, sat on top of a concrete beam and block floor, with 300mm sprayed insulation on the underside, so it will be slow to respond. I was originally looking at Heatmiser Neo stats and multiple zones, but now thinking that due to the slow response, that the whole ground floor, circa 100m2 will eventually even out temp wise, and may be better controlled via weather comp and the modulating mixer valve. Has anyone any real life experience of this set up? It's a big learning curve for us, our project has gone from an estimate of six months to over 18 months in now, and we are keen to get the floor screeds in and heating going before winter. thanks Andy
  25. After much heart ache, time and tears I'm looking for some advice from you guys regarding my heating system, which is completely separate from DHW. I plan to directly heat my slab with ASHP using Willis heaters as back up. Hydraulically does this look ok? Input much appreciated.