ProDave

-10 IS realistic as an outside temperature up here but not for many places in the UK. Bet even at -10 my heat loss was about 2.5kW so a 5kW ashp, about the smallest you can buy, would only spend half it's time heating the house, so plenty of time to heat the DHW.

This ASHP is about 10 years old, well outside guarantee and this is the first time there has been a failure.

I was back today. I confirmed the 300V dc and 15V dc supplies to the motor are present, and when the compressor starts, the other 2 (exact function not determined) connections have variable voltages present. One will be the speed demand. So the motor is dead. The list price appears to be just over £400 plus VAT plus postage. That is a criminally high price in my opinion. Anyway I found one listed on ebay for £200 so that has been bought an on it's way.

For what it is worth, I previously owned a property in a similar situation. I briefly thought about trying for permission for a separate dwelling, but soon concluded, even if it was possible, it would leave the original small house with little garden, the new house would also have a tiny garden, and they would have to share the same road entrance and parking making it even more awkward. I ended up instead extending the original house making it nearly double the size and that met with no opposition and was a better use of the space.

There is a "building" shown in the corner of the existing plot. Is that a garage for the existing house built right up to the road? If so that will be in your favour as the building line and visibility is already breached. Where will the existing house park? I expect both would have to share the same entrance as I doubt a new one would be allowed closer to the corner. Make an offer "subject to planning" and submit a planning in principle application. If that is rejected you can walk away with little cost. A suitably anonymised streetview screen grab might help.

I would question what that meter is actually reading and is it true? for a sanity check, I would read the dial on your electricity meter (not any in home display if you have a smart meter). If you know the time of the sterilisation cycle you can read your meter before and after the cycle and see how much electricity it is really using. Try and not use any other big loads in the house during that time to get an accurate reading.

My plumber up the road called me today. His Mitsubishi ASHP has stopped working. Model number PUHZ-W85VHA2 Symptoms. It just does not work. No errors shown on the in house display panel. Went outside took the cover off the control panel on the outside unit. Gave it a heat demand and watched. After a short while the compressor started, but the fan motor did not start. After a minute or so the compressor stopped and the on board 2 digit 7 segment LED display showed the code U8 which means fan failure. The fain looks very similar but not identical to my fan motor in my LG ASHP. It has an inbuilt variable speed controller. It is supplied with 320V dc (rectified 230V ac) and has a few low voltage control inputs. Unlike my motor, it does not identify on the label what wire does what. So testing today was somewhat limited, other to confirm the 320V dc is pesent. The motor has the part number RG61V143H35 on it. What I have done so far: I have found the service manual, it can be downloaded here https://www.manualslib.com/manual/769585/Mitsubishi-Electric-Puhz-W85vha2.html#manual And the Mitsubishi parts list is here http://www.mitsubishitech.co.uk/Data/Ecodan/Air/Monoblock/Outdoor/PUHZ-W/2012/PUHZ-W85VHA2_SP_OCB465A.pdf From that I have determined the Mitsubishi part number for this fan motor is S70E10763 Next steps: The service manual tells you how to check the 320V and 15V supplies to the motor, so I will go back and do that. There are no test points on the control pcb and the connector does not lend itself to meter probes, so I will splice some test points into the motor lead before going back to do more tests. The only 2 fault conditions identified in the service manual are faulty motor - replace (list price about £400) or replace control PCB (no idea how much that would be) I think the chance of repairing the motor is nill, as far as I can tell all the electronics inside the motor are encapsulated in a plastic moulding. More to come I am sure.....

All scaffold will wobble and risk falling over if you push it to extremes. I bought a load of Kwikstage when building my house, and when I sold it, I kept enough to scaffold one wall of my house. the scaffold lives on a rack in my garden and the boards are stored dry in a custom made enclosure under a raised decking area outside the back door. Much more heavy and needs 2 to assemble it compared to a lightweight tower. But even that needs some bracing at height. You can see in this picture scaffold up the gable wall and the square frame sticking out towards you in this photograph exists just to give it some more bracing.

Is the 2 port normally open or normally closed? Is there any other source of heat e.g. a stove?

Most convert the 50Hz ac to variable frequency ac to power the compressor. I take it you are trying to get something working off grid with PV and dc batteries? Try looking at units made for caravans?

One of the panes is cracked and that has allowed moisture to get between the panes. The glass unit needs replacing.

Build the footings either side of the channel, and bridge the gap over the channel with reinforced concrete lintels. Build wall off the lintels. Why make it difficult?

I assume these are let as separate units or a hmo? It would be most unusual to have 2 separate flats sharing one supply. Who pays the bill? let alone a third unit sharing the same supply. Now you want to add a 4th. Forget lighting. It is the big loads that add up. If you are serious about this I would first shift everything that can be to gas. So gas hobs, gas water heating and showers running from gas HW. Then you are only looking at other stuff on the limited electricity supply. Why are you not doing this properly and getting a separate supply to each unit?

The point about electric panel heaters in bedrooms, is a well insulated air tight house with mvhr most of us find does not need any heating at all in the bedrooms, even up here in the Highlands. But a lot of people are not comfortable with no heating so installing electric points for panel heaters just in case you find you do need some bedroom heating, is a comfort blanket and cheaper to install a few cables that never get used, than a whole lot of upstairs UFH pipes that never get used. If you think you want upstairs cooling look at fan coil units that normally go in the ceiling and will do heating and cooling. The cost of them has put me off and so far we have only had one spell of weather when I might have liked them for cooling. Re the grant. I bought all the parts and installed my own ASHP for WAY less than £7.5K. You only have to look at posts on here on the subject of heat pumps and grants to see it does not seem to work in the customers favour. You might naively think the installer would charge a fair price for the materials and a fair price to install them, then deduct £7.5K leaving the customer with a very small or even zero bill. Sorry to say that optimism will soon be dashed when you start getting real quotes and one is left wondering how can they charge that much?

Actually I don't think that is the OV10 vent there, that is a mock up when working out how to do it. The builders fitted the counter battens not me, they cut them that length. Yes vent fixed through membrane and tray

This is what I did in a similar situation Eaves tray on first. Membrane lapped over eaves tray Counter battens than battens. OV10 over fascia vent on next Then tiles, bottom tile resting on OV10 vent. The OV10 vent is made for this job, it is in line, most other vents tend to "turn a corner" so the outlet would face downwards.

Don't throw it away. Easy repair. I was given 2 by a joiner, both "worn out" and replaced for free by Makita under guarantee. In both cases it was the front bearing of the motor that had worn out. I bought 2 replacement motors for about £20 each from ebay. Mine is still going strong, the other went back to it's original owner.

Not this build but previous one, first self build 20 years ago. First house with UFH upstairs and down. Had planned bathroom layout (3 bathrooms) with normal rectangular 900mm shower trays and laid UFH pipes accordingly. I even drew on the floor boards where the UFH pipes were. But we decided 900 by 1200 shower trays would fit much better. Cutting the hole in the floor panel for the shower trap, yes of course in a different place than it would for a 900mm square tray, I suddenly wondered why there was a fountain of water coming out of the floor.

I had similar flow rate issues with my ASHP (different make and model) when first installed, and the only way I solved it was to buy and install an in line flow meter so I could see what flow rate was being achieved regardless of what the sensor said. In my case it was only an on off sensor (enough flow or not enough flow) and I needed a real reading to see what was going. on. I solved it by adding a second external pump to increase the flow rate above what the inbuilt pump could achieve. The fact you have an actual measure and it has been decreasing, suggests there is an actual problem. Which again is where an independant flow meter would help.

I don't know the law, but I would have expected the unresponsive owner would have sought legal advice. To remain silent may not be his best plan.

Are these new ones the same in all respects to the old ones apart from 2 vs 3 bolts? Or are the new ones also smaller section material in places?

You need to take this up with the bench supplier. The reason for the failure is not your concern, though you may want to enter dialogue with them to help them improve their product and understand why it failed. And if they were sold for domestic use they may reject any claim. Where they sold knowing they were for commercial use?

This puzzles me. The neighbour has an end of terrace house. You want to join on to his wall and insert another house making his a mid terrace house and in so doing devalue his house? And you just expect him to say yes with no compensation for the fact he will have more neighbour noise and a lower value house? Or if you can't seek agreement bully it through somehow? I don't know what the law actually says, but I do know I would not want to own a house where a house wall is on the boundary and so could be subject so such devaluation.

Pictures would help. but I think this is describing something I questioned. Below ground wall build up was done as "block on flat" as above, no cavity. I get that bit. But the bricklayer laid a course of blocks on flat, then a second row of blocks of flat exactly on top of the first ones, i.e. no bond. Then the next row was staggered creating a bond followed by another row exactly on top with no bond. So in other words the blocks were staggered / bonded every other row. Now I questioned this. It would have been no more difficult to bond every single row of block on flat and surely that would have been stronger? so why did he not do that? His reply was that is how he was taught to do it. So it is a question for bricklayers please, why not bond every single row of block on flat? EDIT here is a picture of what I am trying to describe, block on flat courses bonded every other row.

T&E in conduit is fine with the added advantage of no junction when going from outside to inside.