Hot Water Immersion Cylinder
Hot Water Immersion Cylinder
Author
Discussion

badboyburt

Original Poster:

2,043 posts

201 months

Saturday 22nd October 2011
quotequote all
The thermostat in the immersion cylinder has failed, noticed a burning smell in the cupboard and see the cable has arced out on the fitting, replaced cable and fitted a new thermostat.

I still dont have any hot water so possibly when the cable arced out the stat it might have possibly damaged the immersion itself, anyway get out the box spanner and tried to remove the complete immersion but no joy, any tips or tricks as I dont want to split the cylinder.

Its a 900 x 450 cylinder with a vertical immersion.

Thanks.

Arthur Jackson

2,111 posts

254 months

Saturday 22nd October 2011
quotequote all
You've checked fuses etc??
To get it out; Use a flat ring spanner if you can or box if it's all you have. NEVER one of those cranked ones..
Give the spanner as much force as it needs to 'almost' move the cylinder then hit it to twist it out. Sustained effort is MUCH more likely to tear the cylinder than impact. Loosen it with the cylinder full, incidentally, then drain enough water once it's loose to remove it.

badboyburt

Original Poster:

2,043 posts

201 months

Saturday 22nd October 2011
quotequote all
Arthur Jackson said:
You've checked fuses etc??
To get it out; Use a flat ring spanner if you can or box if it's all you have. NEVER one of those cranked ones..
Give the spanner as much force as it needs to 'almost' move the cylinder then hit it to twist it out. Sustained effort is MUCH more likely to tear the cylinder than impact. Loosen it with the cylinder full, incidentally, then drain enough water once it's loose to remove it.
Fuses are fine, should have blown when the cable arced but didnt, I fitted a new one which I know works, Ive dug out my flat ring but its no good.

Cylinder is full as the bloke who I paid many £££££'s to fit it a few years back didnt fit a drain off valve.

herewego

8,814 posts

237 months

Saturday 22nd October 2011
quotequote all
Have you checked that you have power at the element?

badboyburt

Original Poster:

2,043 posts

201 months

Saturday 22nd October 2011
quotequote all
herewego said:
Have you checked that you have power at the element?
Power is getting to the thermo stat but not the element, hence why I want to remove this one and fit a new one.

Arthur Jackson

2,111 posts

254 months

Saturday 22nd October 2011
quotequote all
badboyburt said:
Power is getting to the thermo stat but not the element, hence why I want to remove this one and fit a new one.
If it's getting TO the thermostat, is it coming out the other side???

Harpo

482 posts

206 months

Saturday 22nd October 2011
quotequote all
bbb, do you have a meter to measure the resistance of the element? With the electrics off of course! No point removing it if it's okay.
If it does need replacing check the thread on the tank is clean and use a few turns of ptfe tape on the new element. Have fun!

badboyburt

Original Poster:

2,043 posts

201 months

Saturday 22nd October 2011
quotequote all
Arthur Jackson said:
badboyburt said:
Power is getting to the thermo stat but not the element, hence why I want to remove this one and fit a new one.
If it's getting TO the thermostat, is it coming out the other side???
Its coming out of the thermostat but not into the element.

badboyburt

Original Poster:

2,043 posts

201 months

Saturday 22nd October 2011
quotequote all
Harpo said:
bbb, do you have a meter to measure the resistance of the element? With the electrics off of course! No point removing it if it's okay.
If it does need replacing check the thread on the tank is clean and use a few turns of ptfe tape on the new element. Have fun!
Yep the element is cooked, I just want to get it out and fit a new one, last thing I want to do is buy a new cylinder.

Shaolin

2,955 posts

213 months

Saturday 22nd October 2011
quotequote all
I did this a while ago. I was told to bang the spanner (proper big box one - about £8 from B&Q I think) to loosen it, but noticed the cylinder started to distort around the heater. I got a long pipe (2-3 foot?) to fit over the handle and extend it and it came off quite easily with steady pressure and no more distortion.

herewego

8,814 posts

237 months

Saturday 22nd October 2011
quotequote all
You could try squirting penetrating fluid all around the fitting, but whether it could actually penetrate the joint I don't know. Couldn't do any harm though.

Arthur Jackson

2,111 posts

254 months

Saturday 22nd October 2011
quotequote all
Shaolin said:
I did this a while ago. I was told to bang the spanner (proper big box one - about £8 from B&Q I think) to loosen it, but noticed the cylinder started to distort around the heater. I got a long pipe (2-3 foot?) to fit over the handle and extend it and it came off quite easily with steady pressure and no more distortion.
This is why box spanners are a bad idea. You need the effort in line with the nut, not 30mm above it. Believe me, impact is always better than steady pressure.

Shaolin

2,955 posts

213 months

Sunday 23rd October 2011
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Arthur Jackson said:
Believe me, impact is always better than steady pressure.
You probably have more experience than me, but in my case, it was the opposite - so not always.

Magic919

14,223 posts

225 months

Sunday 23rd October 2011
quotequote all
Shaolin said:
Arthur Jackson said:
Believe me, impact is always better than steady pressure.
You probably have more experience than me, but in my case, it was the opposite - so not always.
Note the part about box spanners.

spike ST500

1,295 posts

179 months

Sunday 23rd October 2011
quotequote all
I prefer a box spanner, as can put equal force on both sides, to prevent heater twisting in tank.

I just tent bend flat spanners!!

If a combination between force, and shock blows don't work, then you need to drain off the top 2"-3" of water, and heat up the old immersion with a blowtorch, to help loosen the thread.