Immersion troubleshooting - is there anything else I can test

[ericmark]

I had the same problem with my immersion heater, I want to get the whole unit changed as it is too short, and am still waiting for a plumber to change it, so I have set the thermostat a little lower for the moment so the cut out does not trip.

I would agree with the comments about the guy masquerading as an electrician, so easy to put the clamp on around the cables to see if working, there was no excuse for not getting it working, so would not use him again.

Even when it seems likely that the extra over temp trip is not needed, I would not risk it with a thermal plastic header tank, with a steel header tank even if water boils all it does is spit out boiler water down the over flow pipe, that was a regular event when I was a boy and we used coke fired aga to heat water.

Since you say you have a back boiler, likely your header tank can stand boiling water, so bypassing the second over temp trip is no problem, but with a thermal plastic tank this can be the result picture from the report on BBC of baby's death but with a back boiler you should have a metal header tank.

 

[Emit]

Dam I forgot to add pics and stuff. Next I’d forget the bronze float . Then I’d forget I’m in the real world

 

[DP]

Immersion isn't providing any hot water. There's not gas to the property, just a coal back boiler, which isn't currently lit.

Here's what I've done so far, can I do anything more?
Pressed the reset switch on the thermostat
Replaced the thermostat
Called out an electrician to confirm electricals are all OK, but he didn't have a clue about anything else to do with it
I had a good careful look, and tested the connectivity across the elements with my multimeter. Resistance was 19.8 ohms.

What might be wrong here? Can I test anything else myself? Is it plumber and new immersion time?

Test WITH POWER OFF, each connection to earth.
Are you getting 240 on the element itself?

Immersion heaters often split if moisture gets into the powder insulation inside the sheath. Split sheath can be checked by testing to earth.

 

[HERTS P&D]

JESUS WEPT!

Just replace the immersion!

Andy