Replacing an Immersion Heater

[coxinio]

Hi all, first post on here.

My immersion heater appears to be faulty, the cylinder seems to boil, it occasionally trips out the electricity and there is some dripping from a small crack in the outer plastic casing.

I have ordered a replacement heater and immersion spanner.

Can anyone offer me any advice on the best way to go about changing it?

Are there any steps I should follow, things i should not forget etc.

Any help is much appreciated.

 

[Diyisfun]

Ensure you switch off/remove fuse. Make note of the wiring terminations. Do not over tighten. There will be other tips, Im sure

 

[EliteHeat]

Turn off the cold supply to the cylinder!

 

[bogstandard]

Sometimes its possible to rip the soft copper tank due to the pressure need to move the "Nut" retaining the element unit. Could try some WD40
Switch of all electricity at the mains if you are not sure of your wiring
Its a very simple job - though you could wind up needing a new tank

 

[Agile]

Nobody has mentioned the most important point !

Try to loosen the boss nut BEFORE you empty the cylinder as the water pressure will help to hold it rigid ( like an inflated baloon ).

If its a top entry element you will not need to drain much water out. In fact because drain cocks are usually seized and/or do not reseal, I usually just use a towel to mop up the 1/2 litre of water that comes out after you have drained from the hot tap.

Tony

 

[coxinio]

Thanks for the info so far guys. Will I need to turn clockwise or anti clockwise to remove the old heater?

 

[Diyisfun]

Anti

 

[croydoncorgi]

Think again before you act!

The threaded flange the heater goes into is large-diameter. The copper wall of the cylinder around it is thin (or if it's an old cylinder, VERY thin). I assume you've never done this job before. A lot of force, correctly applied, is needed in most cases. There is a big risk that you'll tear open or buckle the cylinder.

Unless you KNOW that it will unscrew easily, I strongly suggest you get someone in to do it.

 

[Nige F]

Question from Herts. answers from London saying get "someone " in ........from London ,perhaps Too far for me and my 24inch stillsons

 

[Agile]

I can assure you that Croydon CORGI does not travel north of the river except for the very occasional curry meal and he is mainly into larger installation work rather than small repairs.

Herts is a considerable distance from London and I am sure a local plumber is more suited.

In any case he thinks that he can do it himself!

Tony

 

[croydoncorgi]

Not true!
I still get tempted across the bridges by the Sirens of Westminster, Chelsea and Fulham!

 

[coxinio]

Right guys, why is nothing ever straightforward?

I have removed the old heater and installed the new one, wired it up as per the supplied diagram and how the previous one was wired.

After trying it switched on for a couple of hours there appears to be no change whatsoever to the temperature of the water. I've checked the wiring again and everything seems to be as it should be.

Does anyone have any ideas of what might be causing this problem? Has anyone had this problem before?

Any help at all appreciated.

Matt

 

[tincup]

Hi


Check for 240V.
Check fuse.
Check the terminal screws make contact with bare wire not insulation.
The stat may have tripped. There's a very small reset button on the face of stat, make sure down.


Hope this helps.

 

[coxinio]

It now appears to be working, after another play it seems the temp on the new thermostat increases by turning it anti clockwise, whereas the old one was clockwise.

Its always the little things lol.

 

[Agile]

Perhaps I am over cautious, perhaps instilled by working for BBC Engineering.

However, when I test anything I start at the minimum setting/power and then gradually increase it to the correct operating point.

Tony