ProDave

More pictures please of any other plumbing stuff near the UFH manifold. There is no sign of a pump or blending valve, so chances are it is circulating water far too hot through the UFH pipes. And there should be a motorised valve or 2 to switch between hot water and heating. As many pictures of all the plumbing bits please. And there should be an electrical box near the manifold follow the wires from the actuators on the top and post a picture of that. Initial assesment, the original installer didn't have a clue. You are going to probably have a steep learning curve or find someone that does understand such things to sort it out.

Good point, there is mention about starting current an mention the compressor may not start if too much cable resistance, suggesting it is not an inverter drive. More reason to reject it.

As long as you apply for the self build exemption before you put a spade in the ground. That bit is important.

I take it this plot of land does have some form of planning permissions? You probably want to resubmit planning for the house you want, and include on that temporary planning for a static caravan as accommodation while you build. You can buy a second hand static for not a lot of money. Many on here have been temporary caravan dwellers, including me (twice)

I tend to agree. The manual talks about tank temperature sensor and control of valves etc but then the wiring diagram does not show where they connect to. I would go ahead with your plan to return for a refund as "not as described" I would be tempted to connect power to it and power it up. It won't run for a whole host of reasons but I would be interested if the controller display matches what is shown in the manual.

Can you post pictures of ALL the PCB's inside the unit and all the connectors on them please to see if we can shed any more light on it. If you have an electronic copy of the manual can you post that as well please?

If you have bottled LPG you will find a very similar set of restrictions on where you are allowed to site the bottles in relation to drains, air bricks, or other openings, opening windows and doors etc. For all the same reasons, to prevent escaping gas entering the building.

That looks to be a capacitor in the output circuit of a switching power supply. By the time it gets that bad, it has usually blown something else, but if you have a soldering iron and feel lucky you could try replacing the light blue one with the top split open. That £35 one is a "refurbished" used one. It has a 12 month warranty, but if I bought that I would look at the soldering of the electrolytic capacitors and any that had not been replaced already I would replace with good quality replacements.

It does seem to me a little odd to actually have the ASHP control a hot water recirculation pump. Most people wire that independent of the heating system with timers, sensors, etc which is a whole other topic how you want it to run. It might just be simpler to do that?

No, I am not aware of any domestic accessories that need ferules. That is mainly for terminating stranded cable.

Are you sure those options don't refer to a split system (unit and outdoor unit) where I think you have a monoblock? Check the obvious first, is power to the pump being turned on? any errors showing on the controller? And the vital question, is this a newly installed system and the pump has never worked, or did the pump previously work and has stopped working?

Fit MORE insulation under the ground floor slab, a lot more. 300mm is probably a good target to aim for. And wider cavity with more insulation in them. You build a house once and get one chance to do it right. You will never get the chance to improve it later and will probably regret not doing it right. You are aiming to get the heat input down as low as possible. UFH should then work fine. If you do it really well like many of us have the house ends up so well insulated you don't need any heating at all upstairs, but fit upstairs UFH unless you are really certain of that and really determined to detail it properly. Do it properly and many of us are heating a house that size with a 5kW ASHP. If you are doing this properly, you get a Design SAP done which will tell you all that. It is a requirement for building regs in Scotland, but so few people seem to get it done down south that I suspect it is optional? It is not so much the design on paper that lets a building down, but unless you are detailing everything yourself, or have a really trusted contractor who actually understands low energy houses, then a typical house gets let down by poor details, e.g badly fitted insulation so cold air can bypass some of the insulation, and poor details at junctions. If you are having a cold loft then the details of how to insulate and air tight seal the upstairs ceiling is one of the major details that is often done poorly. And I know you are only asking about heating, but don't block your downstairs hallway. You WILL get fed up having to go through the kitchem / diner to get to the back. Scrap those cupboards and have a hall you can walk through front to back.

Don't waste money on 1.5mm, totally unnecessary. Use 1mm 3 core & earth and the terminals are large enough for three of those.

Tell them you meet their space requirements. Then the guy on the ground that comes to do it won't care and will fit it into the space you have available.

I see. R290 is a posh name for Propane gas. Propane is heavier than air so they don't want a leak filling up drains, getting into buildings etc. Is is possible to swap to an ASHP using something other than R290?

And then the councils and the government wonder why landlords are quitting that business and there is a shortage of rental properties and rents are rising. Just the latest in a long line of "changes" chipping away at the viability and desirability of being a landlord. Milk the cash cow too hard and the cow goes away.

But if you rotate it 90 degrees from how it is shown with the front in line with the house I bet it will meet the 1 metre from the door opening. They draw ambient air in the back and cooled air gets expelled from the front, so site the front facing the road and the cold air will blow that way not towards your door. Alternatively, if they insist on that orientation, then surely the 1M would be measured in a straight line from the corner of the door opening, to the nearest corner of the ASHP. So how much further out from the building would it need to be for the front edge to be in line with the front of the wall and the 1M distance achieved. Cut a large piece of cardboard or plywood or whatever you have around to the size of the ASHP and go and try it on the ground.

Yes it is a mystery where all the water that is clearly there has been going all the years it has been blocked. Raising the water table in the field I would imagine to the point is appears as surface flooding then drains into the burn. As we have a dry day today, and it is still flowing nicely I decided to follow it with my divining rods. It does seem to go in a roughly straight line across the field for as far as I bothered to try following it roughly following a low point in the field, so it would make sense if it was originally installed as a land drain to dry that dip in the field. If so with a bit of luck that field will be less prone to flooding and less likely to flood into our garden again. Should i send the farmer a bill for restoring his land drain to operation?

As above, 25mm batten and 12.5mm plasterboard is perfect for a 35mm back box.

Taking down a lath and plaster ceiling is a miserable job. But the best way to start from a clean slate with a fresh clean ceiling. Re the walls, I would batten and plasterboard leaving the old stuff there. The main reason being I never ever want to rewire a "plastered on the hard" house again. I left that miserable task behind when I moved to Scotland where most houses are timber frame or battens and plasterboard on the walls.

+1 for Frametherm 32 But what else are you using? 140mm insulation in a timber frame is not enough on it's own. So what else, external wall insulation, something over the inside of the frame? It needs to be designed as a whole package.

Thanks for the clarification. Frankly I would just move it back a touch so the front edge of the unit is in line with the front of the house. So the back edge will be less than 1 metre from the back door. What practical problem is that going to create? Who is going to notice let alone measure it?

Can you explain the drawing? There is a rectangle box and an L shaped box, joined together by a red dotted rectangle. If one is the original and the other the modified position why the different shapes? If there are two outside boxes what are they? In any event I seen no harm in moving it / they back to the L shaped one is in line with the front of the building.

They must all stay together. The easiest way is a fly lead from the earth terminal in the back box to the earth terminal on the switch. Strip a bit of 3 core flex to get a short length of green and yellow for the fly lead.

This is more likely going to be a planning issue if it is in front of the house. Care to post a plan showing old and new location?