I have test fitted the new copper cylinder, but water doesn't get to the rayburn as the bottom coil isnt connected to the main water in t #he cylinder.
Looking in my old cylinder I see holes in the copper tube inside where the 2 rayburn pipes attach.
So I think I should drill through the pipes in the new cylinder so that water circulates to the rayburn.
Is this correct?
George
'ang on. Presumably the cylinder water is what comes out the hot tap. I'm guessing also that a Rayburn is a direct heater, so it doesn't mind the lack of corrosion inhibitor in tap water. If so you don't need a coil at all on the HW cylinder for it, just 2 connection points. But if the Rayburn is not direct heat compatible it would need to remain on a primary circuit with corrosion inhibitor, not tap water.
And if it is a direct heating gravity circulation thing then you'll need large bore piping for it, otherwise you'll get sod all heat into the cylinder.
NT
its 3/4 inch pipe to rayburn and back.
It used to work before i moved the old immersi> > > I have test fitted the new copper cylinder,
I have just found this diagram of maybe how it should be..
But i dont want to break the coil in the new cylinder...
george
OK it requires an indirect corrosion inhibited circuit, so making holes in the coil is a no-no. It sounds from what you say as if it was previously run direct regardless.
To run it indirect you need to use the coil in the cylinder and have a (new) header tank (with ballcock, or you can just fill it manually with a bucket/hose) to keep the primary rayburn circuit full of water. The header tank could sit somewhere above the HW cylinder if there's space. Not a hard job to add one.
If the Rayburn's heat exchanger is all cast iron you probably could run it direct, but Rayburn say not to - there's going to be a reason for that. Likely will rot it through at some point if you do.
NT
I'd better get to the plumbers in bromyard tomorrow and but some 28mm Tee pieces and pipe...
Why are there 2 tanks, cold water and F&E, can i just use the > I have just found this diagram of maybe how it should be..
the inhibiter is a chemical?
does it stop the copper tank and pipes corroding, or just the rayburn's tank?
[g]
fwiw the pipe to the header can be smaller. IIRC there is a rule about having 2 pipes rather than one in case one clogs up - a real plumber will know better.
The current header tank feeds the cylinder which feeds the HW taps, shower etc. What your rayburn needs is a separate circuit that can be filled with chemical.
Can you hook it up directly for xmas? Sure. But you know you'll end up leaving it that way, and I presume one day you'll have a very wet somewhere and a knackered range.
NT
yes. Do check the wiki before buying it.
it won't get into the HW cylinder, it just stops corrosion of the range & anything else on the circuit it's in that would otherwise corrode. Copper doesn't corrode much, though it will corrode through eventually.
NT
if i destroy the bottom coil like the old one was then i cant fix it later!
going to the plumbers tomorrow for 28mm tee pieces, pipe, etc, working on a diagram.
Hope i can share one header tank for xmas without any inhibitor in it.
studying furiously.
The small CH header is a "feed and expansion" tank - so not only does it supply water to fill the primary part of the heating system, it also serves to allow expansion as the water heats, and pushes its way back into the tank. Typically these end up somewhat dirty and full of mucky stagnant water. You really don't want that mixing with your DHW.
You also typically dose the CH header tank with corrosion inhibitor, which needs to be separate from the DHW.
It sounds rather like what you had before had knobbled the indirect cylinder to behave like a direct one, and allowed the DHW to actually circulate through the Rayburn's Hx. Not ideal, but may work well enough if you are not in a hard water area (where the Rayburn Hx will scale fairly rapidly).
Rayburn have offered copper ,Iron and stainless steel boilers/heat exchangers over the years but I doubt the OP has an easy way to find out which type he has. Some of the Iron ones were made with a glass coating.
They are fairly robust even in Iron so a few weeks use without inhibitors may not hurt till he can sort it out properly.
That said we are 4 days away from the 22 nd anniversary of my Sister and Husband bringing their 2 day old baby home to my parents where they were going to stay over Christmas and the following month due to being in the middle of a house move. The evening before they arrived Dad noticed a puddle by the Rayburn, sodding thing had decided that after years of service it was a good time to develop a leaking boiler. Scouring the Counties of Devon and Cornwall on Christmas Eve to find someone who had one in stock and was still open was ?fun?. Eventually found one near Exeter and made the 100 mile round trip followed by a fun evening helping Dad change it over while mother made ?helpful ? comments like I must have it ( the Rayburn) working to cook dinner and didn?t appreciated the suggestion that the toaster still worked. That was a copper boiler which had supplied a direct cylinder for the best part of 35 years, hard water from a private well with a manganese content so high the water could appear ?rusty? .
The replacement was Iron but fortunately the system was due to be upgraded to an indirect cylinder and some radiators added a few months later.
GH
FFS, this is a very safety critical job, please get someone in who knows what they are doing, as you are clearly in way above your head by asking such basic questions. If you do get it wrong, you run the possibility of a steam explosion in the cylinder or Rayburn, with the chance of metal flying all over the rooms they are located in.
The only way the rayburn could ever contemplate explosion is if the circuit were pretty much watertight, no place for anything to explode. None of the options the OP have mentioned include that undesirable feature.
As for a steam explosion in the cylinder, I don't see how that's possible at all. With electric heat perhaps, not with a separate gas or solid fuel boiler.
NT
You would have to try quite hard to do that - this is a vented primary system, regardless of if you do it with a dedicated CH header tank, or as seems it was originally, with a vented direct cylinder. Neither will form a closed pressure vessel.
and even if a closed pressure vessel were formed - as unlikely as that is - you'd still have to get the water in the rayburn exchanger above 100C. Does that happen in a gravity circulated range?
NT
I was copying what was already there, which was a cylinder with holes in the pipes converting indirect to direct, which i have now learnt, and decided to upgrade it to indirect, bought a new header tank today.
I'm aware if there's no breather the copper cylinder could split and drench somebody beneath with boiling water, and that in some cases the return pipe pours boiling water into the plastic header tank and melts it drenching somebody beneath with boiling water ... and that if i light the rayburn without water hooked up then the water tank in it could split and become unusable in the future.
I connected it to electric today and had my first bath in weeks, but am still working on exactly where to put the new little header tank, and a few drips.
Someone on facebook recommends a towel rail to dump excess heat, I know I've got more to learn and evolve the system, annoying that the old tank wore out last week and I've had to do all this in a rush before the Bromyard plumber shop closes tomorrow at noon. But hopefully B&Q will have metric fittings and open next week.
Or else as someone said we might have to use a toaster on New Years Eve !
[george]
Yes it will easily get over 100degrees if we burn sawn up pallets or lots of coal to get the whole house warm, I've only been heating my bedroom but expecting many guests in a few days ...
Water has to get into it somehow. That somehow is where excess pressure vents off safely. Even if directly connected to the mains that would happen - though I don't expect the tank would survive that pressure at all, so again no boiling hot flood.
only a hazard happen with electric heating. Wood or gas boilers can't get the cylinder above 100C. I suppose one could misplumb it, but it would take some impressive cluelessness to route the hot primary water into the header tank first.
Just cut the turkey very thin.
NT
"The small CH header is a "feed and expansion" tank"
The tank I bought today has a plastic cover - so I should drill a hole in this for expansion water?
Or could I just have the expansion pipe being very tall?
How far above the water level should the expansion pipe go to?
[G]HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.