Hope someone can help, this is driving me round the bend. I have a hot water cylinder (separate from the heating, which is warm air from a separate furnace) with a 27" Immersion heater that goes in the top of the cylinder. It's connected on it's own from the consumer unit, via an electronic timer.
For the last 8 years, it's all worked fine - except being in a hard water area, the thermostats and/or elements tend to need replacing every 2-3 years. On Sunday night, the water was boiling so obviously the thermostat had gone.
Decided to replace the element as well, because it's been in for 3 or 4 years and from past experience due to peg out. I thought if I was getting a plumber in it would be better to replace both at the same time.
So, plumber came on Monday and replaced the immersion heater (and thermostat). The new heater is one that has a 'safety cut out' that's supposed to trip if the thermostat fails and the water gets too hot. Sounds like a good idea in theory.
Unfortunately, after partially heating the water, the cut out trips and the immersion heater stops working. After calling the plumber for advice, I reset the heater and it worked again for a short while then cut out.
I called the plumber back and he came back on Tuesday and fitted a new thermostat. Unfortunately, a short while after he left, the heater cut out again.
So, he's come back yesterday (Thursday) and replaced the heater element itself. Guess what - the replacement one is doing exactly the same thing.
What I don't understand is this: none of the wiring, timer or anything has changed and it all worked fine before changing the element. But - I guess it can't be the element or thermostat at fault since they've both now been changed (2nd new element and 3rd thermostat).
So can anyone shed any light on what might be going on??
For the last 8 years, it's all worked fine - except being in a hard water area, the thermostats and/or elements tend to need replacing every 2-3 years. On Sunday night, the water was boiling so obviously the thermostat had gone.
Decided to replace the element as well, because it's been in for 3 or 4 years and from past experience due to peg out. I thought if I was getting a plumber in it would be better to replace both at the same time.
So, plumber came on Monday and replaced the immersion heater (and thermostat). The new heater is one that has a 'safety cut out' that's supposed to trip if the thermostat fails and the water gets too hot. Sounds like a good idea in theory.
Unfortunately, after partially heating the water, the cut out trips and the immersion heater stops working. After calling the plumber for advice, I reset the heater and it worked again for a short while then cut out.
I called the plumber back and he came back on Tuesday and fitted a new thermostat. Unfortunately, a short while after he left, the heater cut out again.
So, he's come back yesterday (Thursday) and replaced the heater element itself. Guess what - the replacement one is doing exactly the same thing.
What I don't understand is this: none of the wiring, timer or anything has changed and it all worked fine before changing the element. But - I guess it can't be the element or thermostat at fault since they've both now been changed (2nd new element and 3rd thermostat).
So can anyone shed any light on what might be going on??
