Draining an old (c. 1955) immersion cylinder

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ClubMan

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Somebody I know has a leak in their old c. 1955 immersion cylinder. Looks like it's corroded at the bottom or base and maybe it's a pinhole leak. Obviously emergency action is required and they are trying (!) to get a plumber out right now.

Anyway I had a look at draining it but there was no drain cock at the cold water inlet or elsewhere as seems usual these days. Is it the case here that the recommended way to drain it is to remove the vent/overflow/expansion pipe at the top and then siphon the water out? I can't see any alternative (short of puncturing it!). I have already shut off the cold water inlet and run the hot taps but since there is no input pressure you cannot empty the tank fully by just running the hot taps.

Also - it's an indirect cylinder like the 4th one listed on this page

copper_direct-indirect.jpg


with a coil for heating the water from the otherwise separately plumbed oil fired central heating system. I'm just wondering if the tank is drained is it still OK to run the central heating or would that cause problems with an empty tank?
 
Re: Draining and old (c. 1955) immersion cylinder

If you can manage to syphon out as much as you can, then you could start to undo the cold feed with a basin placed underneath to finish the job. Actually, you can get cheap drill-powered pump in most DIY sheds these days, that with the addition a couple of lengths of garden hose should drain most of it.

There won't be a problem running the heating with the empty cylinder. You'll lose a little heat to the air in the tank, but that should be negligible.
Leo
 
Re: Draining and old (c. 1955) immersion cylinder

Thanks Leo. I just wondered if running the central heating with an empty tank might cause problems with air pressure or something. Anyway - it looks like there may be a professional on the job now so it might not be necessary for me to drain the tank as an emergency measure after all. At least I learned a bit in the last 12 hours with my crash course in plumbing basics! :)
 
Re: Draining and old (c. 1955) immersion cylinder

No prob., you always learn most in these circumstances, often what not to do, but you learn all the same!
Leo
 
Re: Draining and old (c. 1955) immersion cylinder

Yeah - I nearly bit the bullet and attempted to drain it by opening some additional unused inlets around the back. That might've been fun. Reason - and the housholder in question - held me back though. :D The main thing I learned is to identify and label the various stop cocks/valves around the house because in an emergency situation you probably won't have time to figure them out!
 
Re: Draining and old (c. 1955) immersion cylinder

Be carefull with such an old cylinder the heat exchanger is possibly a hand built one with vertical pipes soldered to two manifolds If there is to much press differential it will leak many of them weep in any case so you may not be able to leave the heating working..Plumbers are surprised when water level in plumbing tank rises when they pressurise old heating systems
 
I don't understand what you are describing. What is the "heat exchanger" here (the coil in the original diagram?), what is "press differential" and what is "the plumbing tank"? I think I need a picture. Anyway the cylinder and attic tank and some piping in question was removed and replaced by a professional since as I hinted at above and everything is fine now.
 
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