JohnMo

I totally agree. Sorry obviously I wasn't clear - the Master bedroom is on its own loop. Master bedroom ES on a separate loop. For the reason you state.

Do you have two immersions, have PV connected to say the bottom and a mains one operated by timer/thermostat at the top. Or could you add a Willis heater, to do the job they were designed for, connected to either PV or the mains. Then you could operate the two immersion system independently of each other.

My layout, for comparison, managed to find a photo, similar layout of house (single storey) and floor area from the looks of it. But 200mm PIR in floor instead of 150mm. Bathroom, hall by front door and kitchen diner on a single loop around 100m long. Lounge 2 loops each 100m long ish. Bedrooms single loop each. Master bedroom ensuite single loop, pretty short. Circa 12 l/min flow rate.

I take it your flow temps are quite high, looks like you could reduce and get a gain in CoP?

The distribution box - plenum chamber cancels out any cross talk.

I found with a thick concrete floor screed, 100mm plus thick, that my heating runs with around 6 hour delay. So much so that nighttime setback starts at 1730 and finishes at 0130. I am running with a flow temp at the moment of about 23 to 26 and have 300mm UFH pipe spacing. Could you operate the two manifolds as a single manifold with a suitable sized single pump. Have a temperature mixing valve upstream (more as an insurance policy, to limit max temp) This basically how mine is running. For me there is way to much pipe in the floor, but seems to what people like to do. (I did 300mm centres, so have 400m in 192m2 on 7 loops), have no dedicated loops in halls, but all room loops go through the hall so I just spread them out throughout the floor. But this will depend on heat load required, to some extent. Don't like pipes under walls , to easy for a numpty to put a drill through a pipe.

Sorry not really agreeing. Areas referred to as zones are loops not zones. T5A, 6A and 7A, operate as a single zone, from a single thermostat they will be the same temperature even if you don't want them to be. Do this as a wireless thermostat so you can position where it reflects the temp you want best. But ideally thermostats should be limit stops on temperature, not temperature control. They are set 1 or 2 degrees higher than your ideal temp. Flow temp settings balancing is used to achieve the room temp. So basically you operate as a single zone to ensure your min flow requirements of the ASHP always met or exceeded. In a 150mm concrete/ screed room internal optimisation will not work, system inertia will be too slow, heating will chase it's self, temps will be all over the place. You could do weather compensation as long as works on a 24hr rolling average outside temperature. With that much pipe in the floor I doubt you will need a buffer, if the ASHP is sized correctly. A buffer is used to mitigate too little flow not too much.

Glassloc-system-instructions.pdf

I have attached instructions and test certificate that details deflects at huge loads it also details the fixing used in the test. The supplier is talking out of his **** 1507-1-GlasslocFixing-and-Wind-Load-Data_0.pdf

That's not standby - that's warming up. Why it takes 12 hours is bonkers and doesn't sound realistic. What does the operation manual say?

Put it on weather compensation so it runs all the time, set the flow temp as low as you can, should give a good CoP and no standby. At setback 2 degrees.

I put my strainer immediately upstream of the prv. Stop cock, check valve, outside tap, strainer, prv to the house.

Wait till next April - they may want an arm and leg also.

We have down-lights, but I am not a fan of loads of small ones. We have 6 big ones in the kitchen about 150/200mm dia, fill the room with light little or no shadows. They are flat and white, so disappear in to the ceiling. Look more like a light tunnel. We have a ceiling that follows the roof line, and selected them as they are only about 20-30mm deep. Used slightly smaller ones the hall and most other rooms.

You need to do your research, as the yield in winter is pretty rubbish. You will be able to do DHW in the summer , but maybe not the heating. Really depends on array size and how well insulated your are. Big array, you may be ok on a sunny day for a couple of hours, but would make sure your ok paying full price electric.

Heat loss difference is basically the area X temperature difference between indoor and outdoor. So let's say the temp difference is 15 for the heating season. 15 x 3.3 x 0.87 = 43w 15 x 3.3 x 1.1 = 54w Heat loss difference is 11w each hour for the heating season, say 180 days. 11w x 24 x 180 = 47 520w or 47.5kWh. In financial terms £4.75 year heating saving at 10p / kWh. Not sure how well insulated you are or airtight, spending the money difference there may be a better use of your money.

A day is along time in politics, everything we thought was true a week ago has all been changed today. But I would think property and land prices will fall sooner rather than later.

Depends on the time of day you measure, if you have people upstairs they are all breathing out moisture. Perhaps your ventilation is less well performing upstairs.

They use a material, that shrinks or expands based on humidity. Use this to modulate the flap, simple reliable stuff that seems to work.

H, Ii put mine after the stop cock, the outside tap take off and a Y type strainer, but before any inside house offtakes. I think they normally come pre-set at 2.5 Bar. I fitted a Honeywell from either Toolstation or Screwfix.

Why not replace with something like this. Then they only open as much as required and do it automatically. https://www.bpdstore.co.uk/glidevale-energy-saver-humidity-sensitive-trickle-ventilator/p/182

True

1. No, but many suppliers will want to offer 1.4. Problem is not the glass but the frames, you need good frames to get 1.2 or better. We have a couple of double glazed doors, which I had Krypton filled, they achieve U value for whole door of 1.1. An insulated door will get 1.0. Increase insulation in floor, walls and roof. Adding solar panels. Adding waste water heat recovery. Better airtightness. MVHR. Improved boiler controls. Will all get you more points on the SAP report.

Solic 200 does includes a 90 min immersion override button - called boost 90 mins. Push button to start immersion. So not sure why you haven't seen it.

I would get you stop watch out, and ensure running that regime is not giving you short cycling, your heat pump needs to running about 10mins as a minimum. Other thing to consider is internal heat loss running a couple of rooms only. What happens is you end up running the heating in the rooms heated, hotter than you would if you heated the whole house. That impacts the CoP so you could be cheaper more comfortable running the whole house at a low flow temp. I would certainly experiment. £3 doesn't sound much but that's 9kWh. Or 30 to 45 kWh of heat depending on the CoP. With the current weather you should be getting a mid 4+ maybe 5 CoP for heating.