PeterW

1. Pipework is too small and doesn’t follow the MIs or BRegs, tundish is mandatory. 2. Yes - the MIs require a Control block with over pressure relief. 3. Depends on tank temperature. If not the bath must have one to have water below 46°C 4. No - that is in the wrong place and must be removed And all of the exposed pipework should be insulated.

Mitsubishi Lossnay 35 running an enthalpy heat exchanger over the past couple of weeks and this is the output (courtesy of the Shelly monitoring) Sits between 51-58% humidity

What spec is the insulation ..?? I make that about 90-100sqm in total, so the cost of 70mm PIR would be around £1000, the board is probably £250 and the skim plaster would be £80-100 or so. That would be £1300 for materials, add paint and sundries and you’ve got £900 left for labour. I don’t think to be honest a lot of that is unreasonable, so I think you’ll be looking at either doing some of it yourself or dropping it although to save the money ..?

You’re paying the builder to do his job ..? Let him do his job. Assume he’s insured and let him crack on and finish the prep.

How thick is the slab going to be..?? Make it 150mm and you’ll get a serious storage heater for your overnight energy. Add in a 500 litre UVC and you should I never run out of water. You’re not making the most of the tariff by using direct electric heating so consider the heat pump now as you will 2-3 times the heat per kW of electric.

most boilers are sized for DHW load not heating load. 28kW is only normally used to give rapid reheat to hot water tanks and the initial surge of a heating system.

Try this https://www.in2gr8tedsolutions.co.uk/info/solar-generation-calculator.php

Yes - it’s just there to stop the floor short cycling the heat pump. Where is the stat that controls the heat pump..? What you should find is the buffer empties and the heat pump kicks in and then the water is going direct into the floor. Have you got thermometers on the flow and return from the manifold ..? How often is the heat pump running ..??

How big is the house and how big is the ASHP ..?

I’d move the cylinder downstairs into the MVHR room and free up the storage space. main en-suite is an odd layout / size and pipework will be fun as it is over an open space below. upstairs circulation space is pretty big - could lose some of it into a nice seating area if there are any views ..?

What about the litre of water a day out of the system when the hot water kicks in..??!! That’s nothing to do with the heat pump, that’s poor cylinder installation.

@Cpd has a brilliant set up he built to do just this.

Have you got switches at both ends or are you expecting to just put the meter tails into the CU and use the main switch ..?

Is that a WC related pun ..? ?

wasn't me .... but someone did suggest it ..!

Is it ..?? Where’s that documented..? I thought it said the ducts had to be sealed correctly which for the Lindab stuff is an internal rubber seal.

https://www.sealantsdirect.co.uk/soudafoam-gap-filler-gun-grade-750ml/

Yep search duct filter housing

We could all ask as it was taxpayer funded ...

not that I have seen - it’s a dumb cylinder with a box of bits the same as any other. They do a pre plumbed one but so does everyone else. Looks about 15% more to have a nice manufacturers badge on it .

Solar thermal is a one trick pony. Save your money and spend it on more PV.

So none of it is rising damp - that’s good then Sewage leak is contamination - not nice to deal with and can’t be disposed of through a standard skip so beware. Ditch the limecrete unless it’s for some sort of eco reason but tbh I can’t see how it would help and I would be getting a decent DPM and concrete into thag floor.

Ok so I can’t see anything in the regs (England or Wales I assume..?) that says to convert from a kitchen that BRegs is required. It is to convert to a kitchen !

Regs have always been done via calculation in all areas from memory. From the ScotRegs 3.16 you have this a permanent air entry opening or openings with a total free area of 550mm2 for each kW of combustion appliance rated output more than 5kW. (A combustion appliance with an output rating of not more than 5kW has no minimum requirement, unless stated by the appliance manufacturer). The diameter of a 50p piece is 27.5mm, so around the same area.

Ok so not sure why you need building regs unless you are putting a bathroom in ..? You are removing items so assume it already has stairs etc ..?? Your point about building regs only relates to the (pointless) indemnity your solicitor got you to pay for which I expect indemnifies you for cost in case the council come knocking or the whole thing falls down. Either way, it is unlikely to pay out ... A BCO cannot ask you to improve a building to current standard unless you are altering that element as part of notifiable works. So if you installed a toilet into a wooden shed stood on your flat roof, they can only inspect the toilet install and cannot insist you insulate the ceilings and walls if the elements have existed for more than 10 years (from memory) Worth identifying the work you want to do then deciding if it is notifiable.