replacing old hot water cylinder

gamston

hi folks, thinking about replacing my old hot water cylinder
can't remove the heater element (not worked for years)
the hot water flow keeps slowing down every few months so I have to connect the cold water to hot water pipes at washing machine and force cold water though hot pipes to remove air lock/muck
tried to remove the hot water pipe from the cylinder but will not move (to see if any old insulation/ muck floating in cylinder and blocking outlet)
looking at the connections on my old cylinder (35+ yrs old) they don't match the "new" standard heights
my ones cold water in 100mm, boiler feed 190mm, boiler rtn 1000mm
1250 mm high 450mm wide
do you think my one was bespoke or just the size they made in old days ?

FreeBear

You may well find that the pipes and fittings are old imperial sizes. So even if you did find a tank that is a straight swap, you'd struggle to connect to the pipes. However, not all is lost. Imperial to metric pipe fittings are available so that you can use metric pipe & fittings - You'll need to modify the existing plumbing to suit, so not a major problem.

A gravity fed hot water system ?
If you don't already have one, a good idea to fit a zone valve to the pipe to/from the boiler (and a tank thermostat).

gamston

yes gravity feed , got zone valves & tank stat,
I'll have enough room to replace pipes with 22mm connectors, think I'll see if I can get a bespoke cylinder (if its cheapish)

southcoastrgi

I'd look at the feed pipe in the roof 1st to make sure there isn't a high spot, I doubt it is anything to do with your cylinder

jk0

I have got quite old cylinders working after removing the cr*p with my Vax through the immersion hole. You need a Monument immersion spanner and a lump hammer. Hit it clockwise slightly before anticlockwise, to break the seal.

markin

Its common for the pipe from the feed tank to need replacing.


https://www.youtube.com/watch?v=F8vYOEzkr6A

gamston

worried about trying to remove nut connectors or the element just that tight I feel the cylinder will twist/rip open
changed most of the pipework to and from the cylinder,
only thing I could do is cut the hot water pipe near top of tank and put probe/gripper to pull out any muck floating near outlet, reconnect pipes with 22mm connector

southcoastrgi

markin wrote: »

Its common for the pipe from the feed tank to need replacing.


https://www.youtube.com/watch?v=F8vYOEzkr6A

That pipe hasn't nothing to do with the OP's problem