Nickfromwales

How did I miss this ? Beer and a pie ! Is this sorted now?

You can always use lpg for gas cooking btw.

They also are a doddle for DIY non-MCS registered installs ( e.g. cheap ) so look at what you need and aim to self-consume all, or as much of, what you generate. If you have electric only, then I'd look at a Sunamp + Willis ( immersion heater ) based UFH system with a second Sunamp as the DHW ( domestic hot water ) provider. Look to store as much of the pv generation as you can by employing a good pv diverter and once you've got a year under your belt, if necessary, you could add a few more panels if so required. Id forget oil or lpg and put the cash into something smarter. An ashp would be a cheap way to solve space heating but when you need it most, the pv won't really be up to providing what you need anyway so £'s per kW ( taking maintenance and lifespan ) the Sunamp + Willis solution has the most appeal imo. That lot fortified with grid electricity for any time the pv hasn't cut it and you've got a clean, simple, and uber-low maintenance solution.

You have to keep that T&PRV on the buffer so you're covered for the terminal failure scenario, which is all the isolations shut off and the immersion heater on and its stat to have failed. Its that situation that dictates the T&PRV's location ( and the fact that its factory fitted with half a tub of thread lock so its near impossible to remove ). Just put a 15L container under it and you'll be fine as the PRV on the boiler should be a lower setting. The buffer one is 5 bar IIRC and the boiler one will be 3 bar.

Nobody understands me....... Actually the whole conversation revolved around a sealed and pressurised TS being used as a buffer, so by the sounds of it, the guy on the other end of the phone may have been half awake. Bugger.

Looking good. 9/10 though I'm afraid......... If you follow the expansion vessel back to the buffer, you can see it could be isolated from the heating system should the right hand manifold be fully isolated and left so for any duration The expansion vessel should be connected independently to the buffer, BEFORE the isolation valves, as its to protect the vessel more than anything. Ultimately if its your house and nobodys going to work on it other than you then you can sleep easy, but the rule is that you never have an isolation, or any other valve, between the EV and the cylinder / heat source. Im such a killjoy

@PeterW, I think my crossed wire just got uncrossed.......cue another call to telford tomorrow.

Thank goodness that rats and mice have blunt teeth and no desire to knaw through things

Ive only ever had to have that done when we've dabbed thin IWI boards on and they have a horrible cup to them.

Ill nip to the offy's for another 8 ace then, and we'll see how this unfolds

Why I said effective A header tank is called that because it has to be at the head / top of a gravity fed setup. An accumulator can be mounted in a basement or garage etc. One is non-potable, and the other is 100% drinking quality, potable water. Accumulators get size according to each instance, just like choosing between a 25 gal header ( CWS ) or a 50 gal one.

Ah, you mean in with the PVA? Not laying an actual set of bonding?

Ah, 3 decades ago yes, probably as good as it got back then . The beauty of the accumulator is that it stores at mains pressure. No electrical connection or reliance on power, no moving mechanical parts, one pipe in / out and if the power fails to the pump that's pressurising it, you keep getting pressurised potable water to the value of the effective / stored volume. Same exact scenario as you have, but clean fresh water. Agreed that as a modern solution it would be done according to what's available and the info / feedback used to arrive at such a decision, so please ignore my 'bad decision' comment as I thought ( assumed ? ) that you'd installed this recently. Oops

A coat of bonding ? On new plasterboard ?

@Caroline What spec are you building to? Just before we all stray off on different tangents. Are you having solar PV ? With some thought and commitment early on, you should be able to avoid the need to set fire to ANYTHING.

After youve spunked all your cash on the various potions, and devices with which to apply them, your have paid the spread. A 4' blade needs some serious skill, and I just about have the wrists for my 18" Ox for flattening off over old plaster etc. No xmas card for you this December ! Dead man walking The last customer who said exactly that asked to borrow my step ladder to skim his bathroom ceiling. When I came in the following morning, the ceiling was destroyed, his clothes were rolled up in the corner covered in plaster and about 8 litres of sweat, and my lightweight aluminium step ladder had to go in the skip as it weighed about 60kg with all the plaster that was on it. Took about 4 hours to clean the floor and walls too. My mate came in that evening and skimmed it for £80. Was like a sheet of glass. Disclaimer : After all this has been said, I really need you to cock it up or I'm going to put 2 stone on from all the humble pie and custard.

Why would he blue grit it?!? Its new plasterboard not 30 year old render ! I give up Blue grit should not even be in the building

or......better to have tiled and made the plasterer cups of tea..... FFS indeed. Please dont f.uck this up at the last minute !!!!!!!!!!!

Best to explain which outlets get served by your gravity system before bragging it up too much The normal pressurised system delivers potable drinking quality water to outlets used for human consumption, so would you go up to the attic and fill a pint glass from it to have a nice thirst-quenching drink? Of course not. Your kitchen sink taps and likely your WC and electric shower ( if you have one ) will all be cold mains fed, if you haven't forked out a good few hundred quid buying and fitting a noisy shower booster pump, so best we lay all the facts down here as I wouldn't have a gravity / open pipe system fitted if it was free, sorry. A combi is the worst example possible for delivery of hot water to outlets in a multiple occupant dwelling where others are flushing WC's / washing hands etc elsewhere at the same time ( for eg ) someone is trying to shower, so given that a combi is a very neat, cost-effective, practical and simple single-box solution, I don't think its fair to beat them up unnecessarily. If you have a pump that sends pressurised water to the 400L tank then I personally think you made a very bad decision there. A cold mains accumulator would have given whole-of-house, balanced, potable high flow rate hot and cold water and would wipe the floor with that gravity tank. No ta. Best we continue this chat by comparing apples with apples.

Not for secure storage I hope . The scrotes will be in there in minutes.

They have a BS number so must be fit for purpose. Personally I'd prefer the rubber ended hand tightened ones as they don't rely so heavily on the nut being quite as tight to create the gas-tight seal. Looks good to me. Would be prudent either way to have a can of leak detector spray to hand specifically for testing after the changeover, due to the cost of the gas. That would mitigate against any concern and guarantee a leak-free transition every time.

Happy days ?

Ah, a guaranteed leak free system ? They don't make one I'm afraid as it's not down to the system it's mostly down to installer error. Yes, components do fail, sometimes catastrophically, but more often than not leaks are caused by poor installation or incorrect fittings being used. When you go on holidays, turn the water off at the stopcock, simples . If your water pressure / flow rate is good, then IMO your about to unnecessarily increase your risks by adding components that you don't need. A 'tank' will give some redundant water storage, but an open tank won't be ideal for potable ( drinking quality ) water provision as I certainly wouldn't want to be drinking from a break tank when I've got cold mains available. Even more so if it's outside and the squirrels ( or worse ) start using it to give the kids swimming lessons . FYI, a "mains water tank" to me is a sealed accumulator, not and "open" aka "break tank". If you NEED an accumulator then it would be best off outside so it stays cold, rather than attain house ( ambient ) temp, and fitted in an outhouse or other frost protected location. The added benefit here is that if it ever fails the house stays dry, but, you can fit them in attics onto a drip tray to manage any drips etc. A stone resin shower tray would suffice for eg with the trap made off to an overflow pipe to outside. If there's a problem, simply engineer a solution. My old boss used to say "If you're coming to me with a problem you should have waited a bit longer and be telling me the solution instead". In fairness we were usually in the middle of one ocean or another, so running to the merchants wasn't an option Best to first decide exactly WHY you want a tank before deciding what type and where it'll go.

Hypothetically....... DO NOT USE BLUE GRIT !

Bingo bango