ProDave

Get a larger tank than you think you need with a high capacity heat pump input coil. That will still work fine with the oil boiler. Plumb the system with two 2 port valves, one for heating, one for HW, that will be easier to convert to an ASHP later. Avoid the work of the devil the 3 port mid position valve.

If I had the 1 year old boiler I think I would be using it. I presume you have a tank as well?

Because an ASHP generally will not heat water as hot as a gas or oil boiler, it is normal to have a larger capacity HW tank, and one with a high surface area input coil for better heat transfer, so sadly you probably do want a new tank.

That's pretty much the standard SSE supply head in use now. And note (to make a lot of electricians jealous) he has a meter with a built in isolator switch, which are common in SSE land.

That reminds me I have 2 parcels that have been in quarantine for about 5 days now so should be safe to open.

I am convinced mine is running on pre release beta testing firmware. My favourite "niggle" is you can only adjust the DHW temperature if the heating is on. So if I want to adjust the DHW temperature in summer, I have to go downstairs, turn on heating on the time clock,. go and turn one of the room thermostats up to create a heating demand, go back upstairs and adjust the DHW temperature, then go and turn the heating off again. When heating is off, it will only display the DHW set temperature and not let you adjust it. Mine has separate "water leaving temperature" settings for DHW and Heating.

The tiles are now down and grouted And I have been doing some more CAD work, cutting a template for the first sheet of multipanel which should arrive on Wednesday I have been keeping several large flat sheets of cardboard for literally years, specifically for this purpose.

The "box of tricks" has a flow and a return pipe. That is it for the plumbing. You would normally make it as a pressurised system topped up with a fill loop. Some ASHP's have a built in expansion vessel, most don't. If you get a decent, inverter driven ASHP then you can set the flow temperature for heating to a different flow temperature for DHW. The ASHP only does one at a time, unlike a system boiler than can do both together. I have my ASHP set to deliver the low temperature for the UFH. The flow and return circulate water around a closed loop, either the UFH or the heat input coil to the HW tank. Control of whether the water circulates to UFH or HW tank is controlled by a couple of motorised valves. So when it's doing heating the temperature coming out of the ASHP will be low. When it switched to DHW (and the valves change over) the water coming out of the ASHP will be hotter (and the compressor will work a bit harder to achieve that) Notice all of that relates to an inverter driven ASHP. The old fashioned direct drive sort just run the compressor at full tilt until it gets to set temperature then turns it off. I have just wired one like that for a customer and it does both heating and HW at 55 degrees. In this case it's feeding radiators soo probably okay, but I really would not recommend that sort.

That ceiling is in a poor state. Have you ever seen the mess made when a lath and plaster ceiling comes down? And i suspect there is not a lot holding that one up. Personally I would take it down and replace the lot with new plasterboard. Yes it's going to be a miserable messy job. OR as a very minimum leave it there and over board with plasterboard. At least that will hold it up. Put in more screws (and of course longer screws) than if you were just doing a plasterboard new ceiling.

I am in a phase this week of "buy as much materials as I can" fearing builders merchants might shut shop.

What does it do you your SAP score and EPC rating? I expect for the life of the boiler you will continue to be able to buy fuel for it but who knows at what price? It's rock bottom at the moment so buy a big tank. In 20 years when it needs replacing, you probably won't be able to buy one. so do you want to plan ahead or be prepared for big changes when that day comes (quite probably a new HW tank as a minimum) What have you against something more modern like an ASHP? Have you REALLY costed the difference between an oil boiler and an ASHP? Don't forget to include the cost of the oil tank and installation of the boiler (or at least paying an OFTEC engineer to comission it to validate the warranty, even if you self install it)

Would heating only upstairs work in an upside down house? I am convinced the upstairs gets enough heat by convection up the stairwell and leakage through the ceiling / floor void. So if only upstairs had heating, how would very much heat get to the downstairs rooms? I would love to hear from someone that has an upside down house to let us know how it works if you turn the downstairs heating off completely.

Many of us with passive house or near passive house levels of insulation and air tightness find no upstairs heating is needed, even here in the Highlands. We have UFH in the bathroom and en-suite more so you are not walking in bare feet on "cold tiles" What sort of U values are you having in the walls, floor and roof, and what does your SAP assesment say about the heating input required? Like many others I fitted electrical points in each bedroom to provide for a small panel heater if I had "got it wrong" and we found heating was needed. Those are still sitting there, unused, with a blank plate on them.

I am sure I could find a washer to replace that. 2 alternatives. Take that drain cock to a plumber merchant and see if the "tap" bit from another drain cock will fit into yours. (take a small adjustable spanner) Or re plumb for a single inlet drain cock and a separate tee.

WHY does the drain cock need replacing? there is not much to go wrong. If the drain tap won't seal it just needs a new washer.

Just for anyone else reading this. the important thing is to report it to the emergency number as a "dangerous condition" to ensure they come out immediately. And just to reinforce what has been said, anything before the meter is the responsibility of the DNO and electricians can't touch it. All we would be able to do is turn off your consumer unit to remove the load.

Have you tried Steico instead? https://www.steico.com/en/products/wood-fibre-insulation/

I have accepted that he does not want it. And asked when he has finished his house he report back his real world energy usage figures. Like @Jeremy Harris we run ours "too slow" I have a "normal, practical, proven" ventilation rate and a "building regs compliance" rate that I can switch it to if needed.

Which element of the build are you hoping to replace with something cheaper?

Thanks, never heard of them. Funny name as they are nowhere near Cromarty? It is certainly worth a call I will ring them on Monday. It's the various merchants in Inverness that have failed to impress.

No I have generally been disappointed with all the timber merchants I have found, in fact I find buying timber a terribly disappointing exercise. So hard to find what you want, and then even harder to find any that's any good. I hate to say it but the last lot of timber I bought for something nice, was from B&Q, and even they have a few sizes of planed oak, but oh the prices. The new independant builders merchant in town had a small selection of planed oak when I was last there, so that is where I will be going on Monday to see in more detail what they have or what they can get.

Thanks. I am going to check on Monday what the local merchant has. I don't need very much.

Could you take it out of the bag and take a better picture?

As it happens I am discussing something else with British Hardwoods. However they don't have what I ideally need 20mm by 80mm. They have 19mm by 70mm which would work IF you could absolutely guarantee it would not be anything less than 70mm wide. Perhaps you could do a size check on the bits you have? I also need some smaller section oak for the door stops, they only do down to 19mm which I feel is too chunky for a door stop, I had in mind more like 10mm. This sort of searching for the right material seems to always take disproportionately way too long.....

It's starting to look like I just need a length of 80mm by 20mm solid planed oak, and cut it to length to make my own blocks. That will probably work out cheapest. They seem to be coming in at about £5 each ready made and that's before I can even find one that's the right size,