Immersion heater confusion

[mikeroe]

I have two Backer immersion heater/thermostats installed in my hot water tank. Both had worked fine for some years. Now, there is no hot water in the mornings. Thinking it was the night-time heater I swapped with the booster heater to check. But I still have no hot water in the morning and the supposedly broken heater works fine when swapped into the other position. So I guess the heater/thermostat is fine. I wondered if it was the electric supply but the light on the isolator switch works fine so I presume there is current. So can anyone tell me why I don't get hot water overnight? I swapped the fuses two but these seem OK too.

[ntl_marc]

 Mike...i bet your on economy 7 and electric heating...am I right? If so there is an interupter at the main consumer device that "clicks" loudly at a certain time of day ie evening and mornings... which is larger relay that switches the economy 7 on and off. Listen out for that familiar click in the evening and mornings it might not work. Usually this happens when there is a timechange ie the clocks go back or forward... and the unit seems to breakdown.This happened to us in the old house and had to phone the electric board for them to change that relay/solenoid at no cost to you as its their equipment.

If your not on economy 7 then disregarde this info... let me know if your are and wether this has helped you!