PeteTheSwede Posted October 10, 2018 Share Posted October 10, 2018 Hi I'm looking at putting UFH into an extension as part of a major renovation, and also putting in something like Evohome or Tado for multizone heating control at the same time. I'm looking at putting amtico or similar in as the floor, which has a max floor temp of around 27/28 degrees. The issue seems to be that neither Evohome nor Tado have the ability to add floor probes in to measure the floor temp (as opposed to the air temp in that area) and therefore I'm concerned about cooking the floor. A bit of reading around suggests that you might be able to put an additional thermostat (such as this https://www.underfloorheating-uk.co.uk/devireg-130-series-underfloor-heating-thermostats) in series with the "smart" thermostat on the manifold, just to make sure the temp never goes above 27 degrees. Is this a workable approach? Has anyone else done this? If I have multiple UFH zones with vinyl floor, presumably I need a floor probe based thermostat for each zone? Thanks all Peter Link to comment Share on other sites More sharing options...
Gone West Posted October 10, 2018 Share Posted October 10, 2018 I guess it won't help with your problem but there are self regulating electric UFH mats that are limited to 28C. Link to comment Share on other sites More sharing options...
jack Posted October 10, 2018 Share Posted October 10, 2018 Would it be possible to limit the supply water to 28 deg C? Link to comment Share on other sites More sharing options...
Temp Posted October 10, 2018 Share Posted October 10, 2018 +1 Some manifolds have thermostatic mixers on them allowing you to limit the temperature going to the floor but it usually limits all loops on that manifold which you may not want. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 10, 2018 Share Posted October 10, 2018 This is what we do, limit the supply temperature to the manifold with a thermostatic valve to ~28 deg C. Relatively cheap and easy solution, and some UFH manifolds come with a thermostatic valve already fitted (ours did). Link to comment Share on other sites More sharing options...
Hecateh Posted October 10, 2018 Share Posted October 10, 2018 9 hours ago, PeteTheSwede said: A bit of reading around suggests that you might be able to put an additional thermostat (such as this https://www.underfloorheating-uk.co.uk/devireg-130-series-underfloor-heating-thermostats) in series with the "smart" thermostat on the manifold, just to make sure the temp never goes above 27 degrees. Not done that BUT go on ebay and search underfloor heating co and see if what you are wanting is available from Ebay. I have just bought an electric mat and kit from them. £150 on their site. Exactly the same thing from them on Ebay £89. I couldn't believe how different it was 1 Link to comment Share on other sites More sharing options...
PeteTheSwede Posted October 10, 2018 Author Share Posted October 10, 2018 4 hours ago, JSHarris said: This is what we do, limit the supply temperature to the manifold with a thermostatic valve to ~28 deg C. Relatively cheap and easy solution, and some UFH manifolds come with a thermostatic valve already fitted (ours did). I did speak to technical support at Wunda this afternoon, and they suggested limiting the flow temperature, although they were talking about limiting it to between 35-40 degrees, as presumably the flow temperature doesn't translate directly to the temp of the floor covering. My concern would be whether limiting the floor temperature means I won't be able to heat the room sufficiently... Link to comment Share on other sites More sharing options...
joe90 Posted October 10, 2018 Share Posted October 10, 2018 I have set the TRV on my UFH manifold to frost and get about 24’ on the flow. Link to comment Share on other sites More sharing options...
PeterW Posted October 10, 2018 Share Posted October 10, 2018 2 minutes ago, PeteTheSwede said: I did speak to technical support at Wunda this afternoon, and they suggested limiting the flow temperature, although they were talking about limiting it to between 35-40 degrees, as presumably the flow temperature doesn't translate directly to the temp of the floor covering. My concern would be whether limiting the floor temperature means I won't be able to heat the room sufficiently... They are good but used to BRegs installs and 40c flow rates. If it’s the Esbe valve you have then it’s lower limit is 35c anyway on setting 1 - you can get alternative thermostatic inserts to take it lower but cheaper to buy online. Link to comment Share on other sites More sharing options...
PeteTheSwede Posted October 10, 2018 Author Share Posted October 10, 2018 2 minutes ago, PeterW said: They are good but used to BRegs installs and 40c flow rates. If it’s the Esbe valve you have then it’s lower limit is 35c anyway on setting 1 - you can get alternative thermostatic inserts to take it lower but cheaper to buy online. Thanks - at this point this is all theoretical and all has to be bought. Just trying to figure out a way of using Evohome (which I quite like) in this context. Link to comment Share on other sites More sharing options...
joe90 Posted October 10, 2018 Share Posted October 10, 2018 (edited) What about using the valve mentioned on my thread about difficulty wiring an ASHP. ://www.wundatrade.co.uk/shop/home/actuator-auto-balancing/ @JSHarris has used one and says it’s good. Edited October 10, 2018 by joe90 Link to comment Share on other sites More sharing options...
PeterW Posted October 10, 2018 Share Posted October 10, 2018 13 minutes ago, PeteTheSwede said: Thanks - at this point this is all theoretical and all has to be bought. Just trying to figure out a way of using Evohome (which I quite like) in this context. Evohome is a rad valve isn’t it not a mixing valve..?? It will sense the air temperature and shut the manifold down which is not what you want. Link to comment Share on other sites More sharing options...
PeteTheSwede Posted October 10, 2018 Author Share Posted October 10, 2018 Evohome can control both radiators and UFH, but the thermostats are air temp sensing, yes. That's the issue I'm trying to resolve. The suggestion I had read elsewhere was that you might be able to put two thermostats "in series", in some sense. This might not be in a physical sense, but would mean that if either the air temp thermostat or the floor thermostat was triggered for that zone, then the heating would be cut. The Honeywell/Evohome website says this on the subject. "QUESTION / PROBLEM Describes the Question/Problem What floor probe is compatible with the evohome system for wet underfloor heating? ANSWER / SOLUTION Describes the answer or the required steps that resolve the issue A floor probe can be added to the evohome system for wet underfloor heating system but the manufacturer of the manifold can tell what type of probe floor is needed. " Link to comment Share on other sites More sharing options...
PeterW Posted October 10, 2018 Share Posted October 10, 2018 Floor stats are too unresponsive - have a read of @JSHarrisblog on this. Link to comment Share on other sites More sharing options...
Triassic Posted October 10, 2018 Share Posted October 10, 2018 His blog can be found here http://www.mayfly.eu 1 Link to comment Share on other sites More sharing options...
PeteTheSwede Posted October 10, 2018 Author Share Posted October 10, 2018 Thanks Link to comment Share on other sites More sharing options...
Triassic Posted October 10, 2018 Share Posted October 10, 2018 I think this is the blog entry you need http://www.mayfly.eu/2015/09/part-thirty-eight-heating-and-cooling-controls/ Link to comment Share on other sites More sharing options...
Zed Posted October 11, 2018 Share Posted October 11, 2018 Hi, we had similar concerns when laying our lvt flooring but our fitter used high temp adhesive which I think can tolerate upto 50 c, I think it's the adhesive rather than the flooring that's the issue, unlikely to ever get that hot but the flooring cost a fortune and we have ufh and south facing bi folds. No problems to date. Link to comment Share on other sites More sharing options...
Nickfromwales Posted October 12, 2018 Share Posted October 12, 2018 On 10/10/2018 at 22:48, PeteTheSwede said: My concern would be whether limiting the floor temperature means I won't be able to heat the room sufficiently... Exactly. If you haven't done a w/m2 calculation to ascertain the floor temp required to keep the rooms at ~21oC then your cart is in front of the horse What thickness is the slab, and how much insulation is under it? These are all factors which will influence how the slab behaves. A pump and blender set like this one is what you'll need. Ask for the 20-60oC thermo head to be supplied with it. Pump option B or C. Forget the floor probe as your biggest worry should be where sunlight is directly concentrated onto the flooring on a sunny summers day. That will routinely see the floor temps get very high if the colour of the floor is mid to dark, however using the UFH pump to just circulate the UFH water around ( a-la @JSHarris setup and a few others ) on sunny days will help to control 'hot-spots'. Well worth checking out other glue types as stated above. Link to comment Share on other sites More sharing options...
PeteTheSwede Posted October 13, 2018 Author Share Posted October 13, 2018 (edited) So I went to the Grand Designs show at the NEC yesterday and spoke to all of the available UFH suppliers about this. A majority were a bit scared of setting up a wet UFH system under vinyl without a probe, and said that Amtico wouldn't honour the guarantee in this case. "What if the design parameters changed?". This does sound like a lack of confidence in their own ability to design the system, but that's what they said. A couple said it would be fine, particularly since the room I am putting it in is north facing. The consensus generally was to abandon Evohome and use one of the other zones systems available that do have a probe (polypipe do one). Even if these other systems don't have TRVs available (eg. Heatmiser) then the suggestion was the run the radiators off a manifold and control them that way. P Edited October 13, 2018 by PeteTheSwede typo Link to comment Share on other sites More sharing options...
PeterW Posted October 13, 2018 Share Posted October 13, 2018 29 minutes ago, PeteTheSwede said: This does sound like a lack of confidence in their own ability to design the system, but that's what they said. My (recent) experience of three of the big names in UFH is a complete lack of understanding of anything outside of min regs properties and anything that is not in their current design set. Most have very little understanding of heat load for a whole house, it’s “about the walls and windows”; low temperature flow is “wrong as the house will never reach temperature”; multiple zones “are the future”; and “no-one wants basic controls, they all want apps”.... Everything quoted above is from direct quote requests from a set of plans, wall specs and requirements given for a reasonably well insulated and airtight new build of 82sqm downstairs and 61sqm upstairs. To give an example of pricing of materials only, they range from £2.9k to £4.7k with the most expensive one including £1,400 of controls alone in the price... and they wonder why people go elsewhere ..?? 1 Link to comment Share on other sites More sharing options...
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