Nickfromwales

Check out https://tornado.co.uk/?srsltid=AfmBOoosdIVoVQ8X45D5y7q25CnrsiL903M2bP-rKjIiqQV0YigJYT_0

As with everything, there are good, bad, and excellent folk out there.

Likewise. My solar go to guy was as curious to know, but the industry in general (and the on site sparkies at the time) were clueless. I even drew a picture on the wall, of the how the pickup coils were positioned and functioned, to show it should be a feature that comes regardless, but also got blank stares.

For a clients build which had some deep lights and mist heads, I just used an off-cut of duct (125mm for mist heads iirc) and some AVCL to create ‘top hats’, and then taped these into cutouts. These were done after the cellulose had been blown in, but wasn’t too difficult or messy as I could push back and compress it enough for it to stay in place for cutting the membrane. A bit of cellulose fell out, but prob not equal to what I needed to remove to create some clear area for the recess, so all good. Doubt you could do this approach before insulation gets blown in, unless you somehow support these when the cellulose gets pressure filled; otherwise your inny’s would become outy’s.

I think these “should”, by the laws of physics, as in EMF passes through coils to register the flow of energy, so should work bi-directionally in principal. Depends on whether the software is told to register the flow in each direction or not, eg it charges you but doesn’t (won’t) refund you. So to answer the question, I’m not sure.

Nice. I went bat-shit crazy balancing out a 3ph system in Leicestershire, as it not only makes sense by design, but also pays long term dividends for the client of the on-site generation and consumption are given proper consideration from the outset; I’d planned the 3ph CU and circuits well in advance of the house even being built, plus all the M&E requirements et-al, so there was a plan in place for when we were allowed on site to execute all of these works. At that early stage I could plan penetrations through steels, ahead of them being delivered to site, but my favourite () bit was being able to see quite quickly that neither the architect nor the SE gave two hoots as to a) where plant was going to need to reside, and b) how pipes and ducts were to get about the building without significant compromise. Getting your ducks (ducts) in a row early on (for power / other services entering and exiting the building) makes so much light work of 1st fix, it’s just a genuine shame to see missed opportunities when these details etc have not been discussed way in advance of the construction phase. Plan ahead people!!

Net metering at the 3ph meter has been discussed here quite a lot, and makes for great reading. In a nutshell you can consume or export on any 1 of the 3 phases, or 2, or 3, and the sum of the activity affects the meter reading in balance. So, you can have a solar system on 1ph, exporting, and be pulling in power over L2, and if it’s 1kw in and 1kw out, the meter stands still. No need for a 3ph ASHP, but 3ph solar and batteries is now pretty easy to resolve, so don’t panic too much here just get the right advice off the right people. @lookseehear If you want a very good designer and installer that doesn’t charge the earth let me know, (PM). If you choose well, then you can connect ASHP > solar > batteries > hot water > EV charger in one family of products that “talk”, with the advantage of rapid EV charging with 3ph. You can have bigger solar and batteries on 1ph, just then you’d go for a hybrid system so the number of panels and size of batteries isn’t the value you ‘ask’ the DNO for permission to connect to the AC grid, aka “AC coupled equipment’”, just the size of the inverter is declared and whatever’s behind the inverter is then of no consequence. Plenty of options and solutions, and I’ve done a good few domestic new builds where the clients had 3ph and large on site micro-generation, with a mix of 1ph and 3ph equipment on site. When I explain the many available options to my clients, with reason / rationale (and how the entire electric arrangement can be harmonised quite easily), the fog soon clears; it’s just folk don’t know what they don’t know, basically. Also, there’s way too many salespeople out there which is why I stay impartial. Lots on here on the subject.

Yup. Zero discernible diagnosis going on here afaic. I’m stating facts. They’ve not stayed to diagnose, they didn’t rectify the zero pressure on the heating situation, they’re just swapping out knee-jerk items hoping that the most common fault is the fault here. The flip side is that someone better could come and actually do some investigation, and THEN start handing out invoices or requests for deposits; (requesting a deposit for stock EV’s is crazy). This screams of them not wanting to be left out of pocket or holding the baby if their assumed fix doesn’t fix it. I expect they’ll get paid and be gone, but the issue won’t be gone, just forgotten for a while. Cold water coming out of a heated UVC is not an issue for T&PRV, so it looks like the issue is the 6bar PRV has opened on the multi-block which means it is that which has failed; likely needs to be stripped down and cleaned / serviced, and then tested for normal operation, before anything else gets changed at (likely significant) cost. I’d be asking what makes them think the EV’s “have failed?”. I'd be asking if the fault returns will they then come and fix what it actually was that’s wrong, on their dollar. I'd be asking why after a service you were left with a system with zero pressure in it. Just crap. Seriously?

One per vessel, so 1x red, plus 2 (or 3) for the white vessels.

Ask these guys for a full diagnosis of the fault, and why it’s occurred, and the solution. Otherwise you’ll be doing this over and over again.

Ask them to supply a 3rd vessel. The valve is in the first page of this thread with Screwfix part number visible

Yup. No getting away from intumescent strips here I’m afraid. Wouldn’t pass muster with BCO but will also be in your b regs spec.

No cursing here, just frustrated for you. As you’re under the gun you’ll want the quickest route obvs. If it’s cold water going out of the tundish then it’s not cut and dry as to what the issue is. The control group (multiblock do-dah that one pipe of the tundish comes from) governs the cold mains pressure to the entire hot and cold system. IF, the water is defo cold then it can mean the cold mains pressure reducing valve has failed, so cold mains water is just being allowed out through the 6bar PRedV, sometimes this will happen sporadically with use of outlets temporarily relieving the issue or network pressure fluctuating. There are 2 places the system ‘blows off’ from, and that’s one. The other is the T&PRV (temp and pressure relief valve) that the other pipe to the tundish comes from, the one high up at the side of the cylinder, usually with a red cap. This operates if the cylinder pressure gets too high, or if the water gets way too hot; bottom line here is, if the hot water is on and the cylinder is hot then the water in the tundish will be the same temperature, eg not cold as you suggest. You’d likely see steam coming off it / out of the tundish if so. Questions are: 1) was the hot water heated or being heated when you say the cold water was detected at the tundish 2) are you sure it was cold? Do consider getting those Tesla valves bought and installed, may be useful to hit different Screwfix’s if one doesn’t have the qty you need in stock, and have these to hand for the chap to fit. Will save you time and money in the long term and they’re quite cheap. These make a proper service / inspection an absolute doddle, and diagnosing issues becomes much easier too, vs having to fully drain down and refill both heating and hot/cold systems every time there’s a need to check / top up the expansion vessels pre charge pressure or identify potential issues etc. Now it’s down to cost and time I guess, but as you’re a rental then I think it’s best to not roll the dice. My 2 cents is to get the 2x cold (white) expansion vessels changed, but to also increase the volume. It seems what you have is not sufficient for this to be long/term reliable, and you don’t want to keep pushing this fault along waiting for it to go again. May as well fix it properly, once. Either change these out for the next size up, or add a third 24L vessel to this setup is my advice. I imagine heating by immersion a lot through summer etc gets this tank super-hot routinely and takes it to its upper limits. Adding more volume is one solution. Setting the temps on the immersion a little lower is another. Eg if you have sufficient hot water during winter from the ASHP, when not heating from solar / immersion, then the temps could be dropped so the safety devices aren’t being pushed to their limit all summer. Without being there I cannot rule out a stray mixer tap back-pressurising the cylinder, but do you know if the cold mains (strictly) only comes in at the plant room and that goes to the control group on the UVC? If both points are so, then the whole house hot and cold supplies should be “balanced”; this is something you could ask the ‘engineer’ when they call out. It’s very easy to just change broken things without finding, or curing, the reason they broke. That’s my concern.

I was confused by this term too. However a robot in cyberspace says this: With MEP on board this should get sorted, assuming some element of heat recovery from ventilation if it’s a sizeable property. The only factor between pipes and heater wires is the functional longevity of the wires. As more info lands here, the more I think this will be a serious chunk of change going into a commercial heat / cool / ventilation setup. Your MEP people may suggest A2A AC as it’ll service both requirements (heating and cooling) and will introduce heat pumps to the situation which would seem sensible.

Nope. Direct electric is near 100% efficient. I did I’ve an external heat generator, then wet manifolds, plus ongoing maintenance, losses, and the I detect nature of heat delivery, you’re going to be worse off unless the cost per kwh is managed; so gas or heat pump.

They failed to do due diligence, just an assumed 2x dead EV’s at 5 years old. Sugar coat it if you wish. This is just shit service.

Clunking in an attic would be on timbers shared by most bedrooms

👆 @SimonD gets what I was looking to achieve.

Lots. So the most efficient way to heat this would (on the info I have so far) be to have the screed act like a radiator. Minimal mass, achieve heat quickly, turn off as soon as the premises is to be vacated. Heating up 150mm (plus another 30mm or more of adhesive and stone) of solid mass will take a long time, but will hold heat longer, just need to understand downward / outward heat losses better to say if this is a good idea or not. Absolutely a no brainer to run this off a heat pump, if this is anything like a long term situation. Convenience comes at cost, so the mention of using direct, on-demand grid electricity to do space heating is one where I also assume someone is happy to foot the energy bills per annum? At that stage I’d probably advise the use of in screed electric heater wires, as this is close to 100% efficient, less losses.

Ffs. I googled ‘model’ and ended up back here…..

This is lacking a lot of info. 150mm composite what? Purpose of building and anticipated w/m2 heating needed, and what’s heating it? Floor covering? Lots more detail required or answers will be based on assumptions

And he should / could have used the opportunity to state all of that and book a return visit in. They didn’t. =💩

I use contactors every job, hence me saying it was my understanding that ‘they’ did this function. I’ve not used Shelly’s before, but they seem an elegant enough solution for not much money. @TerryE used solid state SSR’s to power up his heating and hot water gubbings, so the attraction is there if you want silent operation vs the clunk of a contractor. @RedSpottedSev, you may want to consider the clunking of 3 contactors and how / where you mount these things. Due to the size, I assume the Shelly’s are contactors and not SSR’s. Anyone living with a Shelly care to comment?

@canalsiderenovation Don't run back into the arms of these dickheads out of desperation. They've not done a good job here, just perpetuated their revenue stream and kept themselves in business. As part of their visit, they should have diagnosed, not just said "fit a bunch of new stuff". FFS. At the ABSOLUTE minimum, they should have asked to charge you for an hours labour, to check the red vessel pre-charge pressure, to ascertain what is going wrong. The system is too young to have major faults, this is a mountain being made out of a molehill IMHO. The issue(s) is NOT diagnosed well enough yet, so we need to know if the discharged water was warm or hot, and if the heating blew this off or the UVC did. Without this info you, and the aforementioned dickheads, are just flying blind. Leave the hot water on via the ashp and use your showers, you'll be fine for the immediate. Turn off the Solic, even though excess PV at this time of year is negligible anyways, which will reduce the magnitude of the situation.

Just put a 4th RCBO in the aux CU and run it to a double socket so you can plug stuff in downstream. Easier and cheaper to get this done in one hit if you’re getting a sparky out.