dpmiller

blocked drain valve? Boiler full of scale/sludge?

That's a variable flow damper made out of foam and costing about a fiver?

^ as Dave mentioned, I'd be looking at the "supply" flow and return direction.

are the flow and return the right way round at the manifold?

Thanks all. Damp isn't ever going to be a problem anyway as the whole subfloor is poured on a Radon barrier and they're internal walls.

@PeterW 1400x900 trays. No I don't want flush with FFL. I'm aiming for 10mm or so above, but final finish isn't decided yet. Guessing 15mm will cover the final finish, which is likely to be tiles. So (say) 18mm plus a thick mortar bed or 25mm and a thin bed of tile adhesive will get me to the height I want I was thinking/ wondering more about how much movement there might be in the PIR rather than how the tray would be supported as such.

So I'm finally starting on the ground floor buildup. It's 50mm poured screed on 150mm insulation (100mm PIR/50mm graphite EPS). I'm unsure of how the tray works in this situation... The tray is (IIRC) about 45mm thick, so I'll need to set it on ply/OSB/cementboard to get the levels right. That bit's OK. But how does said underlayer sit on the PIR, is it just bonded down or should it extend under the screed edge too, to "key" it in? It's in a corner so two walls and two floor edges. ta

but that's more about the keel than the weight surely?

what does "fail safe" mean in this context?

umm, are you sure about that, our screed is a hemihydrate gypsum, and has no laitence...

what issue do you have with the gypsum stuff @Russell griffiths

hemihydrate here. Very impressive stuff.

the receiver has the relay in it.

this kinda thing: https://www.ebay.co.uk/itm/BRAND-NEW-GREENBROOK-THPW1-C-DIGITAL-WIRELESS-PROGRAMMABLE-THERMOSTAT-FREE-POST/283987840343?epid=5012080247&hash=item421efe8d57:g:8hIAAOSwFqZddnMN

On todays sites they're pretty hot on belts- the second (green) beacon on top indicates belt on AFAIK. I'm guessing that the digger in question didn't have a full cab or the door was latched open?

I'll only buy Soudal in the fancy Genius can now, can sit for weeks and be reused immediately.

why not get a cheapie wireless and stick the receiver downstairs at the bottom end of the wires?

Nope, we'd no desire for anything other than 2g UPVC. Nothing about the look of fancier stuff did anything for us, I certainly didn't want any timber that might need maintenance, and even thermally I couldn't justify the extra cost within our tight-ish budget.

Recommended doesn't mean you can't , they just don't want stagnant pockets of water in the jacket. If you've plenty of flow on the pump, there's no problem with same-side circulation

why was a garage/boiler house unit put in the house anyway? A white cased one would only have been a few quid extra at the time...

Might want to visit your local catering equipment firm if you want really big, and likewise if you want a good chunky prewash tap rather than the domestic type with a piddly spray. https://www.bes.co.uk/plumbing-supplies/kitchens-catering/pre-rinse-system/

get a velux and just don't open it?

Stick your info into LoopCAD and see what it comes up with. 100m is a sensible max for each loop but the more similar you can get the loops the better IMO.

is the setpoint really 30C?

The Miele in Peter's photo has the inlet solenoid valve in the grey bit, and orientation doesn't matter IME. Other brands can use an excess-flow "waterstop" which may be a bit more sensitive.