ProDave

(not sure why it copies as a landscape photo in a portrait frame) Most manifolds have a row of flow meters, but yours does not. Assuming the pump is running, feel each pair of pipes and see which one(s) are getting warm. Each of the actuators on the bottom has a "button" on the top. Which buttons are up and down? How many rooms does this feed? Does each room have a room thermostat if so are they all turned up high enough?

You will need to give us a bit more to go on. What type of UFH wet or electric? Pictures of manifolds and controls if wet? WHAT was replaced and by who? If they could not get it working did they say why or they don't know? Have you asked the previous owners in case something somewhere is simply not turned on?

Yes turn off the "water heater" switch and report back the changes.

Only if insulated properly and nicely air tight. I suspect this house might want some.

No mention of renewables like solar PV?

Have you started the transfer? If not I can give you a referal code that will give you £50 credit.

Electric boilers only make sense if you can run them on a cheap off peak tariff. Economy 10 makes quite a bit of sense as you can put most of the heating load onto the cheap rate. But a MUCH better idea for all electric heating is a heat pump. If gas is available it will be the cheapest option no doubt about that.

Mould growth is a result of cold walls (poor insulation) and condensation forming. Not helped by poor ventilation leaving moist stale are lingering. I don't expect you have this problem with ANY modern method of building with a decent level of insulation and importantly with everything well detailed. Then add mvhr to ensure fresh eficcient clean dry air and the chance of mould is nil,.

And aim for an air test of much better than 4.0. Detail it properly and get a much lower actual air test value. Are you fitting mvhr? What do you want from the house? A really comfortable house that needs very little heating, or as cheap as possible build to just scrape through building regs and have higher heating costs?

Yes definitely turn off the immersion heater switch. If the immersion is controlled by the HP controller for anti legionaires it should not be in 24/7

In your house perhaps. If I need to "strain on the pan" I will go and choose whichever toilet in the house is furthest from others so I can strain in peace.

If it is just standard kitchen cabinet carcasses then there will be a sound gap at the top as well as few kitchen cabinets go right to the ceiling, those would be unusually tall gable end panels for that. But why do you want the washing machine in the toilet where it is a more cramped space to get to to load and unload it? Why not have the washing machine in the kitchen as well and a bit more worktop above it in the kitchen? I once made a short bit of thin wall in a situation like that, a number of 25mm battens horizontally between the two proper walls and 12.5mm plasterboard each side. It made a good solid short bit of wall 50mm thick.

Shouldn't the expansion vessel be upright? I have never seen one on it's side before. And when the plumber comes back get him to sign the comissioning sheet for the cylinder, both to validate the cylinder warranty and for building control to see. Though I am not sure I trust this particular plumber to know how to do it properly, he clearly can't read some simple instructions.

How about a manual "purge" button. So ONLY when you are expecting to use the basin, press the button and it will dump water down the drain until it senses the hot water has arrived. No waste dumping water when you don't want to use it, and no different to you just running the tap manually until you feel hot water has arrived. It would not be difficult to see that able to be packaged as a commercial product. Hmmmm................

I have one of the Mistubishi / Kingspan enthalpy mvhr units in a timber framed house. I don't have any humidity metering but just what issues are you expecting? I have no condensation issues anywhere so what problem do you anticipate?

Deep mid winter here, snowing hard. Next week the average temperature might just creep above 0 for the first time this year.

Is the drawer going to close?

My take with this would be pull out each nail one by one using my ancient slide hammer nail puller, and put screws down the nail hole. Almost guaranteed not hitting pipes or cables as you are using the same nail hole.

I would be interested to see the daily readings for heat pump an immersion once you have a few days readings.

What are you going to use for cooking? The bit issue with most of these tariffs are you get a really expensive slot between 4pm and 7pm 30p per kWh not being uncommon. Are you happy paying that much to cook your dinner? are you going to shift your eating times? Or are you going to install a gas hob and oven so it does not bother you?

Check VERY carefully that the builder IS insured for this. Does your own building insurance know what work is being done and what have they said?

If the floor surface temperature is anything close to 40 degrees, and the house is well insulated, it would feel like an oven in there. something is not sounding right.

Do you have a thermometer on the UFH manifold, that will tell you what the temperature of the UFH water is. Like @joe90 our UFH floors don't feel particularly warm even walking on them in bare feet, more a question of they "don't feel cold" Typically with the UFH on the floor surface temperature is about 22 degrees. @nod don't panic about cost. Our 150 square metre TF house built close to passive house levels of insulation costs less than £250 per year for space heating with the ASHP. And others (probably in a milder climate than the east Highlands) have even lower heating bills.

Are you hoping the solar PV will power the whole house? What about heating? do you not have a mains connection? I am not sure that FLT batteries are still the "go to" storage medium now.

Very commendable if it can be "self heating" but how long will the expensive construction take to pay for itself Vs passive level timber frame and small heating cost? And they were marveling at it achieving about 14 degrees inside. I don't call that "warm" I did note the WBS not sure if it was installed yet but it would make sense with the woodland they have.