Nickfromwales

Can you do the same with the cold main shut off, and the cold tap on the kitchen sink open wide, please. This is the path we've chosen......best to embrace our final destination......

If you are happy with caveats because you want a "thin" system, then just treat the floors like a very nice radiator. Simples. You'll get heat relatively quickly when you need it, but suffer a very big hysteresis; unless you can get the flow temp dialled in very well and address the under-over shoot with a bloody good (~0.1-0.2oC increment) thermostat.

vs dig the trench for a new main, pay for it, and find out it did the square root of fcuk all to improve the situation? A 300l accumulator doesn't take up a lot of space.... 🙏

AKA "Welsh modulation" lol It's a good boiler then, on paper, but I wonder how well it deals with particulate build-up if installed in a situation where its constantly low-flame and running a 'less-than-great' cycle pattern? Oil likes to burn hard and strong, for a decent burn cycle afaik.

Yup, that's the kiddy. That should make the (new / old whatever) boiler very happy and let it go on to live a full working life AND enjoy retirement

Ermmmm.....the installers knew this at the time I presume, and carried on anyways; knowing there were 5 actuators that needed to be connected (to a wiring centre that can take 5 Act's and 5 stat inputs per space). Buy a 5 zone wiring centre, or is that somehow too easy and they don't make one (which would be ridiculous). Last house I moved people in to had 19 loops over 8 zones. Shirley, this manufacturer does bigger wiring centres?!?

Is it an oil boiler that can modulate.............?

@Mattg4321 Are we talking here about being happy with the brief joyful 28lpm, or the crap flow rate after the EV has discharged? Leave the mains alone, and fit an accumulator, unless you can be 100% sure that there is a pot of gold to be found at the street that a new main supply will provide at the stopcock?

If you were sealing around PH rated windows in a certified PH then I'd say "non", but for this job "Oui".

https://www.amazon.co.uk/Expanding-Insulation-Insulating-Applicator-Dispensing/dp/B0DHGS84DG?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&smid=A2WJKG6BSKMDO&gQT=1&th=1

@Mattg4321 Have you got space for a 300l accumulator to go onto the cold mains in the plant room, to supply the control group with a steady (artificial) cold mains flow rate? May be a better, cheaper, and simpler spend vs digging up the garden. Would make the plumbing function very well indeed, and may remove this noise issue. If you know the supply to the house isn't rotted or lead or totally knackered, then leave alone and install a full cold mains accumulator and move on with your life a happy chap.

It's an oil boiler? So zero modulation? If you have a 230v signal that you want to connect to a zero volt arrangement you just isolate with a rely. £20 or so in TLC etc and job done. Can you not energise the C of the timer from 230v L terminal, does the MI's not state this? Most are zero volt out of the box vs 230v out, so you can link L to C and energise the relay of the timer so it then gives 230v switched out.

Me too.

Ok, so not really hot enough for micro-bubbling; this you can get when heating with 1 or 2 immersions at ~80-85oC where the water goes milky. You see this with a combi boiler when you run the hot tap really slowly and the water gets stupid hot in the PHE. Run the milky water into a glass, count to 3 and the waters completely clear again. Very curious, and I am thinking maybe the EV has a manufacturing defect. I think I'd put some money down one one possible eliminatory alteration, and that would be to tee the EV off the control group where it's designated to be connected in the MI's, and try that. Regardless of the cold mains, I don't think it should be doing this. The 28 lpm at the bath tap, does that start off blasting out and then tail off to a lower, constant lpm flow rate?, eg characteristic of the "EV as an accumulator" quotes. Bear in mind that they ALL do this to some degree, just yours more excessively it seems? Have you tried a wet test pressure gauge on the Schrader valve, to measure that pre-charge pressure in real time (taking one test at cool and another when hot?). You could then watch it whilst running a basin / bath tap etc to see how this performs. My 2 cents.

What temp is the UVC heated to?

You'll need to turn the water off, disconnect the pipes, cut the valve free, and look as to how you can affix this back in from behind, given the current fixing screws holding the valve in place will have been driven in from the front This will need a plumber with a brain, and DNA that promotes a bit of clever engineering of some plywood brackets etc; these would need to be fitted to the shower valve, then it turned away from you, then held in exactly the right place for the facia and handles to go on, And THEN the plywood / other brackets (made to fit by said person) will then get fixed to the studwork and job's a good one Remember the plasterboard will need to be removed to allow the valve to sit forward (tight up behind the tiles). Choose your plumber well, or maybe a bathroom fitter who has done more of these types of installations (as you don't want the same type of dickhead back that fitted this one).

Probably opening when the UFH is the only demand, and has been doing so for a long time, as with the UFH (as mentioned above) the flow from the boiler pump is firing against a brick wall (when UFH is doing very little / house nearly at temp and just one stat is still calling) unless the bypass valves take the strain and open up. Issue is, they just get worse at closing fully as time goes by. I also do not ever fit those types of UFH blending valves as they are notorious for making squealing noises when the hot in / hot out ratio is close or equal. as they try to strangle the flow; this is at it's worst when it's a decent house with very low temp required or the UFH flow to the loops. The knock on effect of that 'water hammer' (in essence) is that is gets sent hydraulically back through the system and wakes up any other valves or parts which want to sing in harmony. UFH is often fitted very carelessly, and I have seen some installs that you'd think I was making up just how shite the install / setup / plumbing to and from was, and that's not getting started on the number of jobs I have visited that just should NEVER had UFH in the first place (70oC flow into the loops and the rooms at 17oC and no more). If the boiler gets changed or fixed, I'd still want a piece of 22mm pipe bridging the flow and return at the UFH, installed as close to the UFH pump as possible, on close couple arranged tees, so the boiler can just whizz back to itself with zero resistance. An ABV is just unnecessary tbf, and the tee in arrangement will work wonderfully well at completely hydraulically separating the boiler flow from the UFH flow. A lot of people forget that the UFH manifold pump is sucking water through the TMV vs pushing it through. It is free to ignore the TMV and recirculate without effort, the same scenario which you should be creating for the boiler pump. I fear lots have been fixed / interfered with here, instead of the culprit, and this has woken the 'old gas boiler gods' and made them all angry. I have to strip my Ariston combi next week as the PHE has started to dribble, and I bet that ends up in the skip and me in therapy.

I don't give up easily, I assure you, and if it was any other boiler or newer I'd say hang in there, but pouring money into a budget (and old) boiler such as a Biasi is like paying expensive vet fees to squeeze 2 more years out of your favoutite goldfish.

May be the integral automatic bypass valve, if the boiler has one?

That’s a very good price!

In flats above shops near me, I noticed the wall build up included a 25mm acoustic plasterboard sandwiched between the dividing stud walls, 150mm studs full filled with acoustic insulation (does heat & sound then) and then 2x 15mm FR plasterboard plus skim & paint. Seemed a very good solution, studs at 400mm OC iirc.

Ahhhh, “1930’s semi”, so you’re either doing a cosmetic makeover or ‘going deep’. Which one, may I ask? And welcome aboard.

Just make it a regular garage with slab over EPS insulation (or PIR from seconds&Co) and take the sting out of the floor with these? https://www.bigdug.co.uk/workshop-flooring-c348/flooring-mats-c402/garage-flooring-c20293/interlocking-floor-tiles-c20294/bigdug-essentials-interlocking-vinyl-floor-tiles-p14434/s65752 Fit a decent sectional (insulated) garage door and happy days. Heat with direct electric as you suggest and accept this is just a garage not a man cave.

I forgot about that gem, saw that in a friends house when we were fitting their alarm & cctv and was something I couldn’t tolerate. I also noticed the decoration around the WBS was displaying evidence of this happening plus general use…

Ah, ok. @Alan Ambrose ? Any issues?