Nickfromwales

The mixing valves do die off with old age. Just put a new one in and you’ll be in the pub for Friday 15 years is a decent stretch for a part that’s constantly moving / adjusting etc. Do you have a magnetic filter in the system? If not, I’d add one when you change the valve.

"Refereeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee". 👉

Say what?! Is that a Scottish thing?? Have you had too much Sudafed max strength tonight?

We'll all just go and kill ourselves now ok, thanks

Then your heat pump will be quieter than a congregation, when the vicar says "does anyone know of any lawful impediment".... lol

All depends upon the fabric quality and energy efficiency of what you replace the existing dwelling with, to be completely frank with you. The device choice argument is moot, if the agreed option is less economical to run than gas one you turned your back on. You'll notice that all the big hitters that make gas boilers are all selling new ones as 'hydrogen ready', if requested. Why do you think they're doing that? If this is not an uber-well insulated/airtight dwelling with eco 'super-credentials' and MVHR with heat recovery et-al, then stick with gas. If you fit an ASHP and it's not a good fit for the dwelling, you'll be burning the planets resources at the same rate of knots with an ASHP anyways. Remember with gas, the network will NOT be going away, only the product coming out of the end of it will change (in our lifetimes for sure). If your heat pump ends up with a CoP of 1:1 then you've basically heating off direct electricity, on demand, and the planet is doomed. Oh, and stop considering your bloody neighbours so much. They'd shit on you in a heartbeat, if it worked out in their favour to fit a noisy heat pump to their home, ffs. Tell them we said "hi". FWIW, a good quality (even a cheap) heat pump will be as quiet as a church mouse coughing into a hanky. If, however, you fit the same heat pump to a dwelling that doesn't compliment it, then it'll be getting an ASBO PDQ.

Concrete screws want a 6mm pilot hole, but with concrete blocks you can pull them loose by over-tightening a short screw. 50mm or 60mm would be best. If you don't just save shitloads of wasted time and effort and gas nail them with a Spit gun.........

My dear Watson. It won’t do anything of the sort! “Fire away”. Blocks will absorb and dissipate the impact.

Use a gas nailer. My Spit gun earned its £500 price tag on one job in 3 days. When are you doing this job? If you cover P&P you can borrow mine? Fixings aren’t cheap, but the time saving/ease of use is insane.

Willis will work inline, but you’ll need to exceed the target kW heat demand to get it to respond well. Prob need 2x 3kW heaters in parallel to give a 22mm feed if more than 3 or 4 rads. Willis have 15mm connections, so when I install 2 units or more I tee them into compression tees which are 15x15x22mm so I can use 22mm flow and return pipe work to the pump and primary pipe work. If you do this, you can get rid of the TS. TBH, if it’s just a tiny bit of heat needed in a couple of places, eg one or two radiators then I’d rip the wet system out and fit electrical radiators in their place and get near to 100% efficient vs the convoluted setup you’re currently proposing/adapting. Link This is just becoming a very odd way to skin a cat as firing up a full wet system for a bit of heat to a couple of rads, heated on demand by direct electricity, is just ‘no beueno’ afaic.

Flue can't be permanently boxed in either, as it all (every single joint) needs to be inspected annually.

Yup, the second boiler is just madness. A flush, chemical treatment, and mag filter is all that's needed here. Jeeeeeeeeeeeesus. Why have they used a plate heat exchanger if the Vaillant is only servicing rads?!

That solution is fine, and as long as the joints are glued or taped you’ll not have any issues there. I removed your duplicate post btw

You’re god-damned right there should be!!! Theres zero stopping the frames from moving. Open the window and push it to see for yourself.

I can see a concrete screw, but no packers

Quite normal for a window company to underside, but what have they done for fixings? Also, often the head of the opening used the window millions and frames for structural support, so I wonder if the opening is suitable to take this simple swap. Worth checking, particularly with curved bays. One way these are otherwise supported is if the floor joists from upstairs project outboard to take the weight of the above elevation/bay. Can you take a pic showing the front and head of the opening? To seal up, if they’ve fixed them robustly, you would want a continuous bead of Illbruck 330 foam Link (NOT regular builders foam) which will reduce noise and draft to an acceptable level, and then uPVC ‘makeup’ usually gets set in place to make things pretty.

Yup, agreed, but the isolations are probably moot as there is just so little system volume above the manifold rails to not have to worry about 'draining the whole system down'.

The combi should have an integral bypass, but that should be a failsafe only. WRT losing the UFH manifold pump and blending valve, I’m not so sure that’s a good idea as then you are at the mercy of the flow temp from the boiler. How long has the heating been on for, and do the floors feel warm/hot with flow going in at 70°C?? The hottest I’ve set these to in adverse conditions is about 45°C to get a floor surface temp of 24/25°C, and a room temp of 21°C. At 70° it should be like Barbados in there. How is this performing currently?

That's the flow out of the pump.

Hi. For one, the flow gauges iirc will only register flow if the water is going into that rail, as the water pushes into the pipe loops there is a slider that gets drawn into the current and that pulls down the flow register in the gauge. As per your pic, the pump is running but the gauges aren't appearing to be doing anything? The other thing, is that pumps are suppose to be mounted vertically, but that's just old school mentality from 30+ years of plumbing (I don't mount pumps any other way) so air can rise upwards with flow vs against it. Also, as the boiler is only servicing UFH via a mixing valve, there should be a bypass, other than the one ion the boiler, so when there is pump overrun (the boiler pump is pumping faster than the UFH is consuming that flow/pressure) it can cycle back on itself. That promotes longevity of the boiler, and shouldn't be dismissed as 'unnecessary'. Finally, does that gauge show 70oC flow temp?!? Who commissioned this and what is the target/design flow temp that's supposed to be going into the floors?

Does the flue exit on that wall or at 90o to it? If the same wall, is it sealed up properly so no rainwater can penetrate and get into the mortar joints? Is this evident when it rains/immediately after, or 24/7?

Yup, they would have known about the paternity stuff roughly 9 months in advance...?

+1. Maybe get a rudimentary bill of quantities done, to show the lender that you have your side in check eg that you know the actual costs required to get to a completion certificate. All you need here is the BCO’s sign off, architects are being dicks.

SBR won’t really adhere to the duct tape, maybe use some 4” scrim (plasterers) tape to give it some help?

They’ve used JG Speedfit, and as always there are no circlips installed behind the collars….. This is why I only use Hep2O (Wavin Hepworth) push fit in every permanent installation I do, and have done so for the last decade. JG has the ingenious flaw of slowly undoing itself over time, and this will be 20X more of a concern with heating as it’s going hot-cool-hot-cool so will expand and contract for the rest of its serviceable life. Get the circlips (collets) LINK fitted before the boards go back down and sleep soundly. Copper is king, always will be, but modern push fit is perfectly acceptable when installed CORRECTLY.