JohnMo

Still wouldn't bother

Our bath has been used once in the last year, I wouldn't bother. Plenty of other stuff to get on with.

Unless you are a commercial or industrial application, then the BS standard it not applicable to a domestic situation. It clearly states 'Scope 1.1 This British Standard describes methods for rating and assessing sound of an industrial and/or commercial nature, which includes: a) sound from industrial and manufacturing processes; b) sound from fixed installations which comprise mechanical and electrical plant and equipment; c) sound from the loading and unloading of goods and materials at industrial and/or commercial premises; and d) sound from mobile plant and vehicles that is an intrinsic part of the overall sound emanating from premises or processes, such as that from fork-lift trucks, or that from train or ship movements on or around an industrial and/or commercial site.' I would revert to the council, and ask them to define the correct standard to use, as that one is not appropriate to a domestic situation. And also state that MCS-020 is the appropriate standard, copy the wording directly from the introduction. MCS-020.pdf

Fans basically work on a watt per m3 basis, so 2 or 1 unit will use the same amount of watts for a given m3/h. Downside is really 2x the amount of filters.

No - it's easy, each unit looks after its self, as long as the air going in and out of each unit is balanced, they are happy (even if it's not they are still happy). They don't care where the air comes from, it's just air it's compressible and it moves about easily, it's not the same as a hydraulic system. One of my units supplies air in to the bedroom and the other sucks it out from the ensuite.

Once the heat pump has got water circulation around the buffer it's not interested in any other part of the system, except when the 3 port valve opens the flow path to the hot water tank is open. So things that affect flow, Flow restrictions - filter blockage - really the most likely. Flow restrictions - pipe size and length. Assume your piping size is ok, how long are your pipe runs, after about 20m on 28mm pipe the 7 or 8m pump could be running out of capacity.

It actually says no more than 3 starts per hour. So 10 mins run time, 10 on, 10 off - X3 cycles. Also saying 10 to 20 could be desirable, but in a general context not specific to heat pumps. So if you need 32L in your system - so yours is big enough not to need a buffer, at 69L. Just run as a single or two zone system and make sure your open system is always big enough. Questions Do you need Trvs on the radiators? Could you balance the system instead? Do you need more than one thermostat?

I also installed a horizontal batten at the bottom, make attaching skirting boards easy. Did the same at top of wall also. But all my wires ran around the house at the top of the wall.

Still confused as they only control a single loop, not sure how they would be a benefit or be attached, so one can control lots of loops

That's a low loss header not a heat exchanger, the auto vent on top is the give away. I would be tempted to disable any immersion until you figure things out. I would wind the trvs to max, and bring flow temp down 10 degrees. If rooms are not getting up to temp add a few degrees. When most the house is the correct temp, balance the rest, to get them where you need room temp wise. Night setback should be on the HP flow temp not the trvs, otherwise you gain little or no benefit. Treat the trvs as limit stops for room temp rather than controllers. Reducing flow temp is key to good a CoP

Little confused what the 2 Salus auto balancers will do, when you have 23 loops? That will only control DT on 2 loops. What happens to the rest? Common theme today, making thing way more complicated that they need to be for no good reason. People must be on holiday, plenty of time to over think and make as complicated as possibly. Conversely I took all my actuators off today, so now running everything as a single zone, one central thermostat only set a couple of degrees higher than target, running WC. Even the Salus actuators were never moving because all loops were alway open.

Really you need a u value better than 0.15, under the house (ground) will never be warmer than about 6 deg. Ventilated area will be at outside temp. So heat will travel down rather than up given half a chance. The worse the U value the more heat from the UFH is lost downwards, so the higher the flow temp needs to be, so you run the flow temps hotter to compensate... Will leave others to advise on the voids.

Over temp un-likely, over pressure also unlikely unless caused by freezing. What pressures are you operating at? What levels of Glycol are you running or are you using freeze valves? We had some freezing nights in April but the days were warm so heating was basically off. Could that of been an issue or are you just freezing the heat exchanger and have no glycol protection or not enough. I think if you are running freeze valves you need additional protection for the heat exchangers via secondary heaters SCOP /CoP is a result of flow temps and or short cycling. How many zones? Buffer or no buffer? Low loss header? Could you reduce the flow temperatures, run longer and at lower temps? 42 at 5 sounds high for a heat pump system.

Could your grandmother change the temperature or switch on the heating, if the answer is yes, wonderful, if no, does it belong in a house. You get run over by a bus, could a 'normal' electrician or plumber fix it? Without spending hours scratching their head? See above. Mines confusing to most plumbers - because I have a big buffer cylinder.

Unless the insulation is really good under the floor in the new and old parts I would only expect high flow temps, not the best performance and large heating bills, when compared to radiators. Are you planning for carpets or hard floors? In the kitchen living dining you will have about 3 loops, the lounge another one or two loops and toilet another, I would treat these as a single zone. Locate the manifold in the cupboard under the stairs, borrow heat from these loops to heat the hall. Locate a single thermostat in the hall to control the lot. Balance the loops to get the room temps where you want them and so they all heat up at a similar rate. Your spare bedroom and en suite I would install radiator and towel radiator.

Strange how the first diagnosis thought process is the tech has failed, not check the bulb or the fuse.

Plus UFH is a slow low temp system, linking to a PIR is point less, the room will still be cold when the person has up and gone elsewhere. If I walk into a room switch the light switch and my light doesn't come on, I change the light bulb, sorted. When I go out I switch the light off. Living in houses for last 59 years, never seen a normal light switch need to be changed. Plenty of bulbs have been changed though.

Really you should consider keeping it simple. UFH doesn't need complex control system or smart anything. Simple wiring centre, have each floor as a zone, or even the whole lot as a single zone. The more you split the system in to small parts the more likely the heat source will short cycle and burn through energy.

Think the flow switch is in a failed condition, so read a huge flow rate. This allows the heat pump to run for a while until the controller logic says, that cannot be correct, let's shutdown. First check the wires for the flow meter meter, disconnect then reconnect the wires first. If that fails the switch may be goosed. However if under warranty call the installer, that's what the warranty is for.

You could try to balance the system, set weather compensation and dump all but one thermostat and use the whole system as a single zone? Big volume of water available to heat pump, long run times, lower flow temps (than on/off times), win - win

Good luck, trouble with ufh is the reaction time, mine is quite extreme at 6 to 8 hours for a change to be seen. So no point relying on thermostats or anything smart. Been there tried and failed. My night setback starts at 4pm and ends at 1am. My thermostats fitted cost £5, they basically do nothing (being set above the room temp), could remove tomorrow and it would make little or no difference to the heating. Read Jeremy Harris's threads on home automation and trying for a couple of years to get really smart with ufh control. In the end it was all dumped and a simple +/- 0.1 hysteresis thermostat installed. On my boiler there are three setting that affect modulation, temperature setpoint, max temperature setpoint and gradient. The delta T is a moving target, the hotter the flow temp the wider the delta T, this defined by the boiler controller. A 30 deg flow temp will have a 26 degree return temp, as delta T decreases, supply temp is increased, this will increase until return temp is equal to set point or max temperature set point is reached which ever comes first. The gradient limits how quickly the temperature ramps up (range of 0-15). Set to O and the gradient is removed, so boiler ramps direct to set point as fast as possible, at low temps boiler trips a few seconds later, this is great for 80 deg flow temps. Gradient 1 it applies 1 degree per min max, this can cause return temp and delta T to go out limits. Mine is set to 2 and it lets the boiler run for about 10 to 15 minutes. At a gradient of 4 the boiler stops after about 3 to 4 minutes, not great. I think most boilers have a gradient that can be changed, but the setting is well hidden. Nothing is written in my installer manual, except a small reference to it, many hours of searching later, I found out what is was and how to change it.

I think implementing DHW cylinder weather compensation is somewhat over thinking things and may not be easy to implement and give little or no benefit. If you haven't purchased your DHW cylinder, purchase one suitable for a heat pump with a 3m2 coil, then you can heat it at much lower temps and get a very low return temp. Trying to heat via a normal coil at low temps gives a small DT and isn't efficient. If you are doing weather comp on the heating, why do you need external control system, your boiler has all this built in, add the external sensor and the Apha diverter valve - job done. Simple over heat thermostats are all that's needed, set a couple of degrees over ideal room temp, balance system to get ideal room temps. Set your WC curve, balance your loops and the system then looks after itself. Adding third party equipment just makes a simple system, expensive and messes with things in an unhelpful way. Efficiency is likely to be low as a result. Based on loads of testing on my system, heating the buffer on a thermostat, will yield an efficiency (gas to UFH heat at the manifold) of around 95%. Leaving the buffer to float on boiler flow/return temps will give somewhere close to 105 to 110%, due to lower flow temps. My previous complicated system (before simplification and efficiency improvements) used 30 to 50% more gas, depending on the weather. My last 30 hours of operation (average outside temp -1) gave a system efficiency of 113%.

It's not set for weather compensation is it? Seen it plenty of time on here recently, where the weather compensation curve has been set the wrong way around, so as it gets colder outside the flow temp also gets colder. Have you checked?

Not got the same boiler, but have found on mine, the following. On the controller there is a user menu and an installer menu. In the installer menu under the info tab, can see what the set point is for the boiler. Ours is running WC, and when I looked last the set point was 30. The heating pump runs all the time in WC, when the return temp has dropped a couple of degrees below set point, the boiler fires up. On mine I can set what is called the gradient, this is how quickly the boiler gets up to temp, I have set this as low as I can, so the boiler run time is high. Once the boiler has got to the set point temperature on the return water or if the max supply temp has been reached the boiler switches off. My max is set to 40, so boiler either goes to 40 or a return temp of 30 which ever occurs first.

I have two Titon units, but found the same units are sold and rebranded by Beam for lower prices. Also found the technical response from Titon was great, when I asked for technical assistance. The unit I bought from eBay for super cheap prices, had a failed motor speed sensor, parts to fix where with me the next day. Can't fault that.