ProDave

Another vote for VP400. Our builders chose it because they said it was rated to be left exposed for longer than most others and ours was a slow build.

But if you put DC into an inductive motor winding, the current flow would be a LOT higher, it would just be the winding resistance, so if using DC for energising the stator winding as a heater, it would have to be a much lower voltage.

Yes but to turn it fully off means turning the power off, and there was mention of 2 hours warm up time required? So not an easy "solution" Until told otherwise, look for an ASHP with a scroll compressor which don't seem to need this heater?

In a well insulated air tight house MVHR offers substantial advantages. I assume the use of "negligible" was a typo? Re that latter questions. Letterbox, don't have one, a box on the wall outside. Fireplace, don't have an open fireplace but if you want fire have a properly flued stove with combustion air ducted in directly from outside, i.e. room sealed. Cat flap, open the door to let the cat in / out etc. Drains won't leak air, the water traps see to that, just make sure all pipe penetrations in and out of the building are sealed.

And to complete the list, Conder and Graff are 2 more air blower treatment plants. On a technical level there is not much to choose between them so often people find the choice is whichever one you can get the best deal on including delivery to your house. In my case I chose conder because I got a good price from Travis Perkins and that included delivery and offload by their own waggon.

You can buy support brackets to fix into a corner like you have, A bit like these Obviously choose the length and diameter to suit your pipe. I would fit one as high up as possible to the roof on the twin wall, and one lower down, right at the single to double adaptor.

Electronic meters only count up the useage I thought at each 1Wh that passes. That is the trick that allows pulsed immersion heater PV dump units to work. By turning a 3kW heater on for short bursts, and then off again, the same small bit of energy is being exported then imported and if the total flowing either way exceeds the threshold it will then be counted, but keep the "energy bucket" flowing back and forth small enough and it never gets metered. But a continuous load, however small would just count up until it reaches the threshold to click the metered count up by 1. However long that takes. My ASHP meter is an old spinning disk meter.

This background / compressor heating load is certainly something I was not aware of and a question you should all now ask of the manufacturer before deciding which ASHP to use. A 200W background load in your house would be bad enough, one in a box out in the garden is worse.

Yes indeed they do. When mine sits idle, it uses almost no power. I meter the energy used by the ASHP using an old dual rate electricity meter, one rate for DHW and one rate for heating. Actually the way the metering is switched that is one reading on the meter meters DHW use and the other reading on the meter meters "all other" use, i.e. whenever it is not heating DHW. Now at this time of year, with the heating off, it seems to be clocking up just under 1kWh per week. which calculates at 6W background load. I will settle for that.

SERIOUSLY look at instead installing a small waste treatment plant. Not very much more expensive, no larger, and the drainage field can be about 20% smaller. Far cleaner output and much less likely to clog the drainage field. The only downside is needing an electricity supply so need to run a cable to it. If you take this advice, choose one that works with an air blower and not one that has moving mechanical parts.

Before or after finishing the bathroom? Is THIS thread really 4 years old?

That's not a "tank" but an expansion vessel.

Just checked, my outer panes are "safety toughened" and inner panes are "safety laminated" both with respective EN numbers.

We have several "low level" windows, and glazed doors, and all BC were interested in was looking at the markings on the glass units to confirm they were toughened glass.

What do you call "cold weather"? Mine has never frozen even the night it got to -18, and -10 is common here. The only "issue" I have is a few drips of condensation running off the inlet pipe as the lagging on it is not as good as it could be. but that is not an MVHR issue. If you clean the filters, no much should get to the enthalpy heat exchanger core.

The moral of that story is when viewing as house, go the the middle of each room and jump up and down......

You seal the gap around the pipe in the top of the stove with a small tin of fire cement.

And a sign of my lateral thinking. I came by it at a previous employer, on a scrap truck outside a lab being cleared out. I "borrowed" it and over a lunch break found the fault and repaired it. Having repaired it so I knew it would work, I undid the repair and sent it off to the appropriate channel to buy it as electronic scrap. Then as soon as I got it home I knew how to repair it.

What insurance is in place to cover the build? could that not cover the "site hut" garage

My experience has been a surveyor will only note and comment on what he sees. so room in roof, which is common here, unless the walls are showing damp then they just make an assumption about what is behind them. The difference between a new build with this spray foam and an old house, is you can be more certain a new build has been done properly with for example a sarking board and appropriate membranes so the foam is not in contact with the underside of the tiles.

And part of the problem has been created by some of the installers who actually market this product as a way to patch up an old roof effectively "sticking" the tiles in place so they won't slip.

You learn something every day. Like for minimum "off" power demand, you want to choose an ASHP with a scroll compressor. If that is a genuine advantage, I am surprised those that use scroll compressors don't make a big thing of it?

If this is just for a French drain, I would have thought you could excavate carefully around / under it and install your French drain as planned with this pipe passing through. I would guess this is a vent pipe?

SW is possibly surge water? A rainwater runoff system? What are you starting to build? if it's just decking, it might not be an issue?

I find it more important to activate boost when showering, so it there is only one controller, upstairs between the bathrooms.