ProDave

A double lined flue is a twin wall flue for insulation and a must when it goes through a ceiling and a room above. What you need is a "room sealed" stove that usually has an attachment on the bottom for an inlet hose, mine is 80mm diameter but others may be different and you connect that to a duct through the wall at low level behind the stove, or you can if you have a suspended floor duct it in from the ventilated under floor space. Make sure your chose stove takes both primary and secondary air from the duct, we found some that took secondary air from the room so not true room sealed.

Adding sealant is a bodge and avoiding finding the reason. Find WHICH joint is leaking, where the black joins the white? Where the outlet from the trap joins the white pipe? Or the white cap on the trap below that? Or is is still leaking where the bath waste joins the bath or where the overflow joins into the black bath waste fitting?

My first question to the seller is WHY are you selling a 1 year old ASHP? In what way has it failed to meet your expectations that you feel you need to change it?

Yes poor install detail. the extract pipe must run straight and flat with a gentle fall to where it exits the building. I bet your fan sits in a dip with the pipe risong either side of it, a perfect "sump" for the condensation to form in.

With MVHR the better air tight the better. It could be a completely hermetically sealed box and it would work well with MVHR In Scotland if your air test is 3 or less, then you must fit MVHR, below 3 and trickle vents are not adequate.

If I am reading that chart properly, you only put heat into the room for a short period and then after the heating is off the room temperature carries on rising and over shoots the set point. This means the UFH water temperature is too high. Reduce the temperature on the manifold mixing valve, it will heat with the floor at a lower temperature over a longer period and hopefully avoid the overshoot.

Earry in the build I set up my own blower door, made from an old desk fan, some OSB, some cardboard and a lot of duck tape, set up to suck air out of the house so it was easy to go around to find air blowing into the house and seal up all the leaks. Best done before the plasterboard goes on. Yes there are indeed a lot of people worrying about costs but what we don't know is how much of that cost is "because" it is an ASHP and how much of that cost would still be there if the same house was heated with a gas boiler? to counter this, there are also several of us hapilly using an ASHP up here in the far north where this last 2 weeks weather is just a normal cold spell that we get most winters. My last weeks ASHP usage for heating was 110kWh so about £33 for the weeks heating and it did not stop working when it was nearly -10. It was also not my most expensive week either, we had colder and more expensive about 2 years ago.

Door apperture was made too high or a shorter door was chosen. Personally I would have boxed in with plasterboard down to the door frame height, which is what they appear to have done the other side.

You need to pull the kick boards off and reach under to seal the PB to the floor properly. At least it does not need to be done neatly as it will not be seen. Is there not proper air tight layer behind the plasterboard?

Most ASHP's only heat DhW or heating one at a time with priority given to hot water. Once your tank is up to temperature it should then start heating the rooms. Keep us posted.

If the manifold water is not hot enough to heat the house, turn the mixing valve up. Once you know what manifold temperature you need, then turn the water leaving temperature on the ASHP down to only slightly above the required manifold temperature.

I can't speak for the English system, but in Scotland, if it takes longer than 3 years you have to pay what appears to be a discretionary amount for a discretionary period to renew it. I ended up paying £100 each time for a 1 year renewal to keep it current until I completed just over a year ago. they make it clear if you don't renew then it would have to be a new application and new regs would apply. I would not argue the fee, but would argue nobody informed you of any need to renew it to keep it going. I guess the other argument is don't bother, but if you ever try and sell it not having a completion certificate will be a problem.

That makes sense. Yes anything can go underground but it may not be cheap. A local self builder here had about a 200 metre run of 3 phase 10KV overhead buried and including his new connection for his house cost him in the region of £10K. It was a must for him as the line went right where the house was to be built.

Just reduce the "water leaving" temperature on the heat pump. No point whatsoever having it set to 50 degrees only to be mixed down to a lower temperature by the mixing valves. But no need to remove the mixing valves.

Ah, so it's a multi house development, not just a single self build. Surely then it is worth paying to have at least one span of that cable run undergrounded?

Turning the handle off should shut it off. If you don't want to tackle it yourself you just need a plumber that can follow that simple instruction, not a specialist heat pump plumber.

Yes the trap should remain full of water, that is it's purpose to stop drain smells coming up your plug hole.

We can only feel and hear the air from the vents when at boost speed. At normal speed, you would have to stand on something at get right up next to a vent to feel the gentle flow of air. If it is running too fast, then it will be wasting heat. Do you even know how to adjust the speed on yours?

I am pretty sure that's 3 phase, neutral and earth 240V so "Low Voltage" in DNO speak. I don't know if that changes how close you can build to it or not? but will still affect materials unloading and if you need a crane etc. I am not sure from the plan you posted earlier which is new and which is existing buildings, and how far from the pole they are?

I think the filter is inside the ASHP perhaps if there is anyone that knows this model could comment. Is is still in warranty? Can you play on the fact you have no heating in this freezing weather to get them to come on an emergency call?

That is exactly what we do. I don't see the need for a fancy complicated control panel.

Can you confirm it works normally in space heating mode, i.e. the pump continues to run and the house is warm, and your problem is only when trying to heat the hot water tank?

First turn the heating off completely so all pumps stop, and confirm the flow meters all return to 0. It is not unknown for them to stick. Any change you make to flow rate by rotating the flow meters should register immediately.

Assuming the inverter is not mounted right next to your electricity meter, then all he is meaning is you have to get a cable from wherever the inverter is, to your incoming supply point to get that current clamp onto the supply cable. He does not literally mean the cable connects to the smart meter, but the the current clamp that is in the vicinity of the smart meter.

The driver would be responsible. You may have issues with delivery drivers refusing to operate a hiab unless then can pull completely off the road onto your land so they are far enough from the cables for the hiab not to reach them. And in any event if you are building within 10 metres of the cables, you will have issues and I think under 6 metres is a definate no (it was when I enquired)