Immersion heater faulty

bobodhi · May 5, 2010

Hi, I've been asked to go look at an immersion heater which isn't working.
I haven't looked at one before and would appreciate a heads up.
Obviously there may be a problem with the power supply or the unit may be faulty.
Would appreciate any comments by those with experience as to a suitable approach to the problem.
Cheers, Kevin

All Sorts · May 6, 2010

Yes new heaters had to be installed (by someone else subsequently so don't know how fault actually manifested itself). I'm sure I heard somewhere in a previous life that you should never megger those elements anyway.. presumably as you'd be shoving x2 or x4 it's normal operating current through a low resistance?

Don't start draining anything until you've proved the thermostat as it's very easy to check that so daft not to prove that as first step. If it's awkward to get at or to see what you're doing just kill power, disconnect the stat and pull it right out. You don't have to drain anything to go that far as the stat rod is covered within the heater assembly. Then it's simply a switch operated by a dial. Any suspicion against the stat just join the 2 wires into it to short it out, then switch on and watch whether the electric meter wheel starts whizzing round or not!

bobodhi · May 6, 2010

All Sorts said:
Yes new heaters had to be installed (by someone else subsequently so don't know how fault actually manifested itself). I'm sure I heard somewhere in a previous life that you should never megger those elements anyway.. presumably as you'd be shoving x2 or x4 it's normal operating current through a low resistance?

Don't start draining anything until you've proved the thermostat as it's very easy to check that so daft not to prove that as first step. If it's awkward to get at or to see what you're doing just kill power, disconnect the stat and pull it right out. You don't have to drain anything to go that far as the stat rod is covered within the heater assembly. Then it's simply a switch operated by a dial. Any suspicion against the stat just join the 2 wires into it to short it out, then switch on and watch whether the electric meter wheel starts whizzing round or not!

Thank you, very useful to hear a commonsense approach to problem solving, it's very easy to miss out the logical first steps (Is it plugged in?) and dive straight into the complexities.