PeterW

Buffer in the attic is fine. It’s only 100 litres so not massive. Can you not also get the boiler up there and free up some utility space ..?? In terms of zones I wouldn’t use individual controls for hallways etc. as you won’t get any benefit and you’ll end up tripling your costs with controls that are pointless. Even a 9 port manifold will easily cope with that pipe volume. Once you get up to 1000m of pipe on a manifold then it’s usually better to split to a second pump.

Firstly ... 200mm spacing will not heat a 1965 house unless you are significantly upgrading the wall insulation and windows etc. Maximum 150mm spacing with that sort of build. You could also just use a single manifold. No point with one per floor on a house that size, but you will need to find somewhere to put a buffer tank as a large combi will not modulate down far enough to provide low levels of heat when you are reaching the temperature set point. I can’t see how you need 9 zones across that area, even with 150mm spacing you’re only just over 500m of pipe so at best I would be looking at a single 6 port manifold on the first floor, and use actuators to control the zones not zone valves to each manifold. That will at least halve your spend on the manifolds etc and there is no issue running pipes down to the lowest loops from an upstairs manifold.

£3k for install is eye watering. If you check midsummer for prices.

Sorry are these GSE in roof install or standard on roof install ..?? Those panels are £105 each, optimiser is £43, inverter is change of £550 What’s the remaining £3k..?

Only certain rooms (bathrooms for example) and habitable rooms. Egger Protect is 16.2kg/sqm for 22mm from memory.

Why are you looking at Part E for floors as it’s not required for a single dwelling

Yes - TorFloor is a gimmick. If you can lay a deck then you can lay spreaders with ordinary P5 flooring. I’ve seen one install with an issue where the floor doesn’t get very warm as they have had to install 9mm Ply to get structural stability and with adhesive and tiles, the output is only 48W/sqm when run from a heat pump as the 12mm pipe needs a very high flow temperature.

Out of interest - what prices are you getting ..?? Does it include installation ..?

Another vote here for enphase micro inverters. Makes installation very simple and you get the full power out of each panel. It’s also a single wire from the roof into a single isolator, only thing you need to find a home for is the bridge unit which is about the size of a cable router.

That is about 350m of pipe so max 4 loops / zones based on 150mm spacing

Can you get road planings..?? Scrape the top off with a JCB and then put the planings down at 200mm deep, and then run a roller over it and it will be as hard as nails.

Sorry meant floor area ..!! and nothing wrong with you providing parts with a 10% handling charge

Ok ... Area ..?? Is the pipe in..? Or the number of loops..?? Pumpset and Manifold here https://www.wundatrade.co.uk/shop/home/underfloor-heating-manifolds-and-pump-sets/premium-pumpsets/premium-pumpset-wilo-erp-pump/ https://www.wundatrade.co.uk/shop/home/quick-shop/wundatherm-quick-shop/manifolds-quickshop/4-port-premium-underfloor-heating-manifold-2/ None of this is rocket science and I would ask the plumber how many he has installed before ...

Buy this and hand it to him .. https://heatingpartswarehouse.co.uk/product/willis-external-immersion-heater/ Then make sure he puts one of these in ... https://heatingpartswarehouse.co.uk/product/reflex-12lt-heating-vessel-8203300/ Then he needs to put one of these in, to fill the loop... https://heatingpartswarehouse.co.uk/product/altecnic-wras-15mm-filling-loop-kit/ That’s less than £100 of bits, and a couple of hours and some nice bits of copper to install it. Does the UFH have a pump built in ..?

I am assuming running an ASHP at night - wouldn’t necessarily run during the day so I agree I’ve put my figures down as night rate as 9p or thereabouts.

Why will it be cooler ...?? Assuming your oil stat is set at 70°C you could replicate this by using the ASHP to 50°C and then top up using the tank immersion to 65°C which will be more than adequate. In terms of cost that adds about 45p on E7 to your daily DHW electricity bills.

Never come across them (but now bookmarked thanks @Ferdinand..!)

Yep same here - TS either opposite S’Fix or within 1/4 mile in 3 local areas

How deep is the back box..? I would cut it back - both sides - and then use a very quick/cheap punch down connector in the box such as this https://www.ebay.co.uk/itm/CAT5e-6-IDC-4-Pair-8-Way-Junction-Box-8P8C-Inline-Cable-Coupler-Terminal-Socket-/224041015912?_trksid=p2349624.m46890.l49286

who's did you use in the end and how much did they cost ..?

This

The discount isn’t related to the credit account it is related to you having a X-fix account (Plumb - Electri- ) and the discounting is at product level. I have a P-Fix account and get 10-12% off a lot of stuff but not everything.

The D shape ones are easily modified. They have an 8mm threaded pin that you can remove and shorten to 12mm long, and then you drill a careful hole with a drill stop and then clean out the hole and epoxy the pin into the hole. A short (1/2”) stainless screw in the additional hole to stop it swiveling.

+1 to this and speak to your insurance company. Get some decent pieces of plywood - thicker the better - and get them laid under the chimney area so if the bricks do fail they hit the ply not the ceiling below.

Just leave the old ones alone - they won’t go anywhere. Any reason for using 140mm hollows ..?