HughF

Roof, including chimney stack, is being scaffolded for flashing repairs and I want to make the most of the scaffolding, so I’m planning on getting my hetas guy to drop the liners at that point. 4 chimney pots on the top - each fireplace had a separate run up the chimney. I will have two liners installed, one per appliance. I cannot drill through the hearth and access the floor void so the external air supply will have to draw from the room. Unless, as I said earlier, I can draw from outside using a concentric flue liner, if such a thing exists.

As I think it is unrealistic to core down through the hearth retrospectively and get a duct into the floor void, I think we’ll have to settle for a grill/grating in front of the hearth. It’s a real shame a concentric flue liner system isn’t an option.

Or no foam in my case. 1” gaps all round, covered with trims.

Fensa install at my Somerset house…. Bunch of cowboys the lot of them.

Last time I fitted windows without BC or Fensa, I just lied when I sold the property - “they were fitted in 2004 when the extension went on”

Just get him on time + materials and tell him to crack on, you’re only paying him to sling pipe and press fittings.

To be honest, the hydronic design of these things is so piss easy, I could sketch it out on an envelope for you and you could just get a plumber to press it all up. It’s not rocket surgery this stuff.

We’re super happy with our trickle vents, has completely sorted out the indoor air quality and humidity.

We did private on our extension, I was panicking about trickle vents as I’d ordered the doors and windows without them (was planning dMVHR) then decided we didn’t want to go dMVHR. Drilled a few holes and screwed them on. BCO didn’t even look at them.

Private or council BC? private seem a bit more lax in my opinion.

Just say you can’t remember the name of the company who installed them, and you lost the certificate they sent you 🤣

Dragging this thread kicking and screaming into 2025, it looks like some interesting developments by Chris and the team at SPRSUN over in China:- £1700 gets you the new, inverter driven version of the old 'Pro' unit - in a more sensible 6kW output https://coolenergyshop.com/collections/air-source-heat-pumps/products/proinverter-air-source-heat-pump-6kw That's a decent price. No idea if it's built on the Carel platform, for that money I expect not, but it has a particularly wide modulation ratio - considerably wider than their r290 unit, or the older r410a units that I, Marvin and dpmiller are running.

Yep, that's a bargain, given the retail price (which is unreasonable)...

I've done some more detailed research on this, including getting a look inside both the indoor and outdoor unit (via a YouTube training video)... Veismann don't do themselves any favours: 1. They call it a buffer - it's a 2 port volumiser purely for system volume for defrost. 16Ltrs seems a little small, but if that's what they want then that's fine by me. 2. They say the 'secondary circulation pump' lives in the indoor unit - the outdoor unit is without a pump so the pump in the indoor unit is the primary circulation pump. Still seems unnecessary to put all that stuff in an expensive indoor unit that takes up more wall space. 90% of heat pumps have the expansion and primary pump inside the outdoor unit, with just a 3 port needed inside the house (or 2x 2 ports if that floats your boat). I'm sure it's a fine unit, but it would need to be magically better than the usual stuff on the market to make me want to choose it.

Any install by a heat geek or other competent installer... Buffer bad...

It’s was just ‘concrete’ off the truck, laid by my builders (father and son team) with me on hand labouring. 120mm if memory serves. Pipes at 150 centers. click down lvt with the integrated foam backing - not glued.

What's this mythical screed you talk of, we used readymix straight off the truck 😀 Tiny bit of self leveller at a transition where we knocked through and LVT straight over the top.

If it has a buffer, it'll have one more pump than needed. Both those are redundant in a properly designed system.

Don't involve BC, just buy them and fit them...

I went triple from ModernUPVC on my house renovation - no complaints.

My go-to supplier for plastic these days, but I think OP wants something more fancy (european style PH windows)

Coil roofing nailer and associated nails….

This is exactly my floor build up in the extension. Except we’re on 200pir and about 120mm conc. works perfect, crack on.

I’ve already got the stove with an external air supply inlet on the back, the ductwork up/down/left/right is no issue. The issue is where to take the external air supply from now that there’s no pipe installed in the hearth.

I prefer to design my systems from the ground up to not need half the crap most of these all-in-one hydro box/cylinders include - buffer, backup heater, extra zone valves etc. I fitted all of mine into a cylinder cupboard that was 480mm wide. No extra pump, no buffer, just a 3 port diverter and that’s it. Given the price disparity between gas and electricity we have here in the UK we have to design for maximum efficiency, unlike other European countries who can get away with less efficient designs.