Barking up the wrong Gravity Coil?!

Hi Mysteryman, many thanx for your reply.

I think the case of what my old type cylinder is or isnt is now getting in the way of what components I'm now left with after advice from Plumb centre and Gledhill. Like anything to do with old kit, I appreciate the real need to able to see it first hand rather than second guess an over the counter description, so I cant blame them for not specifing the precise right kit in direct replacement.

To recap then, I have a Rayburn No.2 ( first pattern) which as you rightly said is rare, especially as this one has the ovens on the right hand side and the 2 fire doors open independently of each other.

I have a new flexilag'd Gledhill Indirect gravity coil cylinder 450 x 900 with 1" tappings and 27" Immersion, and a Polytank 24-16-15 CWT.

Presently there is no heat dump radiator, but am willing to fit one if an appropriate one could be recommended, although the pipework to and from the rayburn is in the opposite direction to the site of the radiator so would this end up being on a dead leg configuration?

The Rayburn will at best be used for 3 months a year for background heat/hot water purposes. All other times the immersion will be used for DHW. Pipe run from Rayburn to cylinder is 4 meters approx, but remodelling of the kitchen will mean the pipework being behind a new stud wall prior to passing through the wall into adjoining bathroom. If these are to be un-lagged, do they pose a fire risk passing through timber studs given the heat they can rise to? At a pinch, I may be able to build the wall completely in front of the pipes so no contact is made.

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As I understand the situation, I'm now needing a F&E Tank connected to the flow side of the Rayburn pipework, but may not have enough room to site one.

Should I just fill the flippin thing with sand and forget connecting it up? It's worrying the life out of my 'worry-wart' mother who thinks the whole house is gonna explode!!! As she lives next door I think she's more worried about her windows blowing in!!

As always, many thanks for your input.
 
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One picture's worth a thousand words as they say.

I can now see that it's a direct fortic.
Also that it's an indirect Gledhill that you've bought to replace it.
Unlagged pipes are not a fire risk.
You won't need a heat dump radiator either.
22mm expansion over the new header tank.
Keep the primary flow and return in 28mm all the way and keep then rising from the boiler to the cylinder.
Take the expansion off the flow and take cold feed to the boiler separately into the return.
 
Its often overlooked that an F&E tank on a solid fuel system should NOT be plastic !


Tony

Can you point me in the direction of any regulation? I believe plastic, if WRAS approved F&E tank, can withstand boiling water for a minimum 500 hours...

I believe it is a recommendation , metal feed & exp tank , also a copper overflow , not plastic , float to ballvalve should also be copper !! not plastic , you might also be wise not to sight the exp tank in the loft that is over a bed !!!

I would have my doubts about the 500 hours , I stress the word doubt ?
 
Yes, I was a bit confused about what your new cylinder was, but now we know it is an indirect, that is all OK. As you say, you will need a feed and expansion tank. As it is a full indirect cyl, you can connect a radiator in as described above.
 
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Thanx Guys,

just out of interest, would the sitting water within the coil and flow and return pipes heat when the cylinder is heated by the immersion? guess the immersion would have to be on for a longer time than the hour a day I was reckoning on. Was just thinking about a towel rail being connected that only gets hot 3 months of the year. Were I not to fit one inline with the system, I was going to buy an electric element and wire in on a timer.

Do I need a rad/towel rail with 3/4" tappings and run in 22mm or can I fit a normal off the shelf job.

Many thanx.

Nick.
 
It won't thermo-syphon away from the cylinder if that is at the highest point.

Your HTR will probably be ok on half inch, it depends upopn the size and the exact layout.
 
The old cyl was a primatic; the new one is an indirect.

Mind you, I was confused too.
 

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