Nickfromwales

A single check will be quite short, a double check longer and with a hex nut for service (in the majority of cases). Defo try what I suggest and eliminate that is my 2 cents.

Copper is the ultimate, but I would feel bad not covering the plumbers time if he's not done anything wrong (at least some beer money if nothing else).

I’ve been doing this for 30+ years chief, do as the wise Welshman says lol. 😜

It’s down to knowing how much heat the UFH is going to actually deliver. Kitchens are the worst as there’s a lot of redundant floor area covered by units etc. Suspended floors just need as much of, the best insulation you can afford, but also for you to foam everywhere that allows draughty airflow eg around the skirting board etc. 2’ of insulation in a room with an open window means the room will never get to temp, as cold air infiltration (and the resultant convection loss of any heated air) will render the UFH useless (at full power) in a second. Wunda will cost the whole thing for you. Simples!

If a rotary pipe “slice” was used to cut the pipe then it would already have turned the end of the pipe inwards, removing any abrupt shoulder that is often the cause of a damaged rubber o ring. If the old joint was desoldered then defo would need a good clean back to copper and the burrs removing. That all assumed ok, as it’s going to leak from day 1 if so damaged, then you can relax. Hep2O stuff is excellent for quality, robustness, and an effective long-term solution here. Where did the leak come from then? The radiator valve?

Is the non return on the UVC hot outlet a single check or double check? I’d look at that next as these tend to be quiet with lots of flow/pressure and noisy with lower values. May be the ‘groan’ off that tbh.

Ok, but don’t use mortar, it’s crap, use flexible tile adhesive instead. Cement is way to friable, and will just disintegrate over time removing any support you assumed it would provide long term. If you can fit / cut a paving slab then cement board should be a doddle?! Again, use tile adhesive regardless not mortar for bedding those too.

Defo lose timber any time you can. Build up with tile adhesive and cement board vs batten and plywood is my recommendation, and live a long happy (leak free) life. 👍

I just recommended Gordon from Bridgend (iirc) who does a lot of MBC Timberframe’s insulation work. He blows all the cellulose stuff in. For PIR / other sheet insulation try Seconds&Co for big discounts on nearly perfect but ‘seconds’ insulation materials. Spoke to their chap at the NSBRC weekend event and they said they can also supply insulated plasterboard too. ”Save money on your insulation, buy more beer”……sign me up!!!

I'd have told him to Go FHS

9/10 it was the £2 relay that opened the gas valve, but even though I could go get one from Maplin I just couldn't take the risk of a secondary fault at (then) my expense for the same PCB.

Firstly, what’s a hefty call-out fee? The PCB is usually a prime candidate at 10+ years with a combi, so nothing terrifying there. Why was a refurbished board fitted?! Usually not cost-effective tbh. The PRV started passing for a reason, so did they check the pre-charge pressure in the expansion tank when they replaced that part to be sure it’s not just put a band-aid on it? Any grants for a free boiler replacement in that area?

You can cut them and go that route, but best to get your BCO's input to see how much overlap and the number of fixings they'd "like to see" used. In honesty, an overlap of 100mm past the face of the supporting structure in each direction should suffice, with a bolted connection, but best to ask first and execute once

Yup. For heating, via thermal storage, you can directly heat the circulating water with a big immersion and use that to bolster/reduce oil consumption (basically by it being seen as an electrical inline heater of sorts), and that will have some benefit of introducing cheap there direct electricity to space heating, but for a domestic heating scenario in a poorly insulated 2-storey home the least capacity TS I’ve installed for bulk stowage is 2600L. That was storing at 85°C to be anywhere close to being useful/effective and to have sufficient sustain. A 300-500L storage tank heated to 85°C would be drained to a useless temp in an hour or two.

Copper, where it's the plant room or where the pipe is exposed and mechanical damage/aesthetics are important, every damn day of the week. Everywhere else, Hep2O is the weapon of choice. JG Speedfit still remains my go-to for pressure testing/temporary hook-ups, but tbh......a fitting which slowly undoes itself over time is not something that really instills confidence. I go to sites where folk have used this stuff for welfare setups etc, and each and every joint has begun to undo, and none have the 'obligatorily forgotten' circlip fitted which sends a cold shivver down my spine of how many of these are installed in homes and are ticking timebombs....? Put a Hep2O fitting together, do the same with JG, and have a look for yourself as to the difference. Night and day IMHO.

The only member of my household that gets a bath EVERY night lol.

+1. Bigger tank, lower temps, less losses, no brainer.

If introducing a single zone of UFH to an existing oil boiler, you may also run in to issues with short cycling. This would require either certain rads coming on in unison as heat loss (hall / stairs / bathrooms), or a buffer tank being added to the UFH circuit, or the UVC being swapped out to a thermal store (with DHW coil inside it for hot water). You'll also need independent (additional) heating controls for the UFH'd areas to 'zone' them; these will need set-back times that start sooner / end sooner than the areas with rads. Ahhhh....the joys.... UFH here would be a 'want' vs a 'need', so forget any savings or economics tbh. You either do an overlay system and suck up the inefficiencies or dig out and fit lots of insulation, either option will have cost and performance impacts / pros / cons / caveats to swing each argument for / against, so choose wisely. UFH well installed is the best thing of all, but poorly installed (then poorly performing) UFH is utter garbage to live with. Dealing with draughtproofing will be your No.1 priority in any of these cases, to lower the amount of heat required in the first place, so always consider a fabric-first approach at all times. Further note that the closer you get to 'airtight' the closer you get to needing to fit mechanical (forced) ventilation too, so yet another can of worms to then consider for Part O....!

Stopping at the eaves will leave a huge amount of permeability, so I doubt this is anything to hang your hat on, and if 3-3.5 is the target then you'll have fabric infiltration beyond the flow rates of the MVHR which means the heated air will be getting lost faster that the MVHR unit can recover it, so consider your next move based on the worst case scenario so you don't make any unwise investments here.

Are the radiators and pipework being upgraded as part of this install?

What he said...

Bonded too?

Yup, if it's wrong to love a V8 then I don't want to be right 🥰

We usually ask for a 400mm bucket for excavation, with one service laid either side.

I've heard that single room MVHR is less than brilliant, particularly with regards to actual heat recovery. If true "fresh in / stale out" then trickle vents become redundant / unnecessary. Most BC officers don't have a Scooby-Doo tbh.