Nickfromwales

@texas If you click on someone’s text and highlight it you’ll see a box appear saying “quote selection” To ‘mention’ another user just type the @ symbol and then the first couple of letters of their username and you’ll see a drop box appear below that you can select their name from. Like I’ve done with you at the top of this post. May save you some typing lol 😉👍

Hi. If you have a pump connected directly to the cold mains, and you are consuming water faster than the mains flow rate, then you’ll be “sucking” on the mains supply aka applying a negative pressure. A lot of plumbers will speak to a sales rep or some guy behind the counter in the merchant and sell the plumber some kit, the plumber will fit it, and no one ever checks if it’s all ok / compliant as they both just want paying. These systems should be designed after a survey, I say this all the time particularly where an accumulator is the intended solution; this way, when I install expensive equipment and disrupt someone’s lives to do it all, it works afterwards (as intended / promised) and has a great service life. If you have sub 11 lpm flow at the main the 1st advice should be to petition your water authority to see if you can get the local supply uplifted slightly; sometimes there’s just been another 30-40 new homes built and they’ve done nothing to maintain your existing supply, other instances could be that the tapping into the main in the street is furred up (I always ask the neighbours if I can test at their outside taps too to ensure it’s not an isolated issue). If you have a system that fills an A>B break tank then you can’t ‘suck’ on the cold mains supply as the system will be hydraulically separated by an air gap in the break tank. These systems should pump would just be sucking that break tank bone dry faster than the incoming mains can refill it. Some very poorly installed systems will see next doors supply drop to zero whilst the pump is pulling. The water authority do NOT take well to that because of reverse contamination issues.

Collapse the boxes in on themselves, leaving the panel with the cables until last. Remove, chase, fit new box. Will require patience and some understanding that every action has an opposite and equal reaction, eg if you fold the centre of the panel in the edges will contort outwards slightly, firstly, and THEN fold in. If you damage the edges of the plasterboard during these alterations then be sure to inject some 330 foam behind the boards and around the box, as this will give you something solid to fill / sand / paint vs ‘flappy edges’. Wet the block work and plasterboard edges with 50/50 PVA/water mix immediately prior to foaming up.

Have you tried Gordon, the chap that does a lot of the MBC frames? I know MBC will be keeping him busy, but worth a call as you can do this at any time and shouldn’t really hold you up being in the queue.

These may come in handy, for injecting the 330 foam into ‘nooks & crannies’ https://amzn.eu/d/736GNiG

The black flexi stuff is the one you need, the other is for much more adverse situations. A bit overkill and a total pain in the arse to install.

+1

If I saw air temp that low coming into the house I’d want it heated somehow. I doubt adding any more insulation will help here as the fan is sucking cold air in and that’s being detected by the sensor inside the unit. Consider an inline heater to bolster through the worst of the winter, as the heat recovery doesn’t seem very good either that unit? Maybe for a much better long-term solution you could consider a far better unit. LINK

I've called off the hit

Cost impact for exploration? Or 6 and two 3’s?

So for thinner insulation, Aerogel is significantly better than XPS / Marmox etc?

Have you run this past ATAG’s tech support yet?

If you can afford it, then ask yourself the question, not us lot!!! If you want a cinema / TV room and you will use it, then I’d defo go for it without a second thought. Has the builder discussed tanking / waterproofing / any need for a sump pump+ pumped discharge? Ask all the questions before proceeding, so costs don’t spiral and you don’t end up with regrets.

I’ll have another look at space / options and reply a bit later 👍

If this was to be the 'ultimate spec' conversion, then between the 2 close-coupled tees would be another 2-port motorised valve that is "normally open". This would stay open until it was energised by the brown wire that provides signal to the radiator motorised valve. The worry would (could) be that, if there is this permanent bypass loop, when the rads are on that may allow the boiler to ignore some of the rads or decrease the flow to them more than you'd want. The second 2-port would allow the system to toggle between UFH only (with the valve open to allow the boiler to recirculate) and UFH + RADS (with the valve closed) to return this to the way it's currently plumbed). This sounds like overkill, but it's actually the correct way to set this up without a buffer or low loss header. Soooooooooo many plumbers just don't get it; that they set things up which appear to work "fine" on the day, week, month or year(s), but the setup is on borrowed time from day 1 as so many parts are functioning under duress.

@Burkle Quick swap and not too hard to do.

Oh, I forgot to say, don't forget to wear cheap disposable gloves.....and absolute must when using this stuff. I guess you bought the disposable "all or nothing" type canister lol.

..do what I've just done for a client with rising steel columns which are exposed externally and internally, which is to bond Marmox boards to them. Even if it just 10-15mm it'll kill the cold bridge pretty effectively. https://www.protilertools.co.uk/product/marmox-multiboard-tile---shower-backer-board--choice-of-size-?gad_source=1&gclid=CjwKCAiAtsa9BhAKEiwAUZAszX4ebPdNBF3SV58FmCOrszr1VvIk-Kl56JF44R-c_219F_0ONBT6ExoCmPkQAvD_BwE Fill any gaps with foam NOT mastic but these can be cut with a track saw etc very accurately.

For the benefit of new members, just giving this another bump.

Post a pic so we can make some suggestions. 👍

One x would have left that as questionable, but 3 x's made me feel special . I felt bad because I never got you a card, or flowers, but there's always next year.

Yup. The mention of weather comp for this is nonsense, and defo needs at least 100L buffer on the circuit of UFH, but prob better off with a TS (with an integral DHW coil) instead of an UVC, but that ship has probably sailed; retro-fit buffer will now be the robust option. Still amazes me how shit a selection of installers there still seems to be out there, as (most) boiler MI's dictate that the installer should surmise if the design is not within their recommended guidelines, and if not then they should "do something about it".... That's been completely ignored here afaic. Oil boiler direct to UFH = 💩

"What happens on the mile....stays on the mile"

I'm a married man, mate, I'll take whatever is on offer.

It's just maths, and not an issue with your currently installed equipment. The amount of water you are consuming, between each event of 'recovery', exceeds the capacity of the system that you have installed. Yes, fit a bigger system and the problem will go away. Simple maths but remember the "gotcha" which is that it is illegal to create a negative pressure on the incoming cold main supply. A prosecutable offence, no less.