Immersion heater water going cold

[MrMick70]

Hi everyone,

I have an unusual problem relating to immersion heaters.

I have a good general knowledge of plumbing, electrics & gas and have done so for the last 50 years.

Over the last two weeks my electric immersion heater does not heat hot enough in the required time.

It is on a timer and goes cold in less than 30 minutes from switch off.

I have tested almost everything, there are no leeks, dripping taps, no thermo-syphoning., including checking the temperatre of the water in the header tank. I have replaced the thermostat. What more can I do?

Thank you All

 

[conny]

2 possibilities come to mind.

1/ Heater element is faulty and not reaching correct temperature before being 'timed out'.

2/ Timer is faulty and not running for the specified length of time.

Can you bypass the timer and switch it on manually for the length of time you normally have your timer set to? Stick a strip thermometer (looks like a photograph negative),to the immersion tank and see what temp. the water actually gets to. Try this before you bypass the timer and after you bypass then compare the readings.

Good luck.

 

[MrMick70]

Thanks for that.

Timer not suspect. Cannot check manually, but I have a spare element, but this does not account for water going cold once hot.

 

[rssteve]

if you aint got a leak, and the water aint going back up to the header tank, and the water is definatly all hot and not just the top part? then you must be draining if off to somewhere. Nabours maby?

 

[JohnD]

either the hot water is going somewhere, like a leak or dripping tap, or else the heat is escaping from the water, like someone has moved the insulation to make the airing cupoboard warmer, or it is thermosyphoning round a pipe.

Or else it was not up to the correct temperature in the first place.

 

[MrMick70]

It is self contained, no leaks, no thermo-syphoning, just a mystery.

 

[MrMick70]

Problem solved.

One learns something new each day.

This wa a problem that I have never come across before. It turned out to be an intermittent break in the heater element. I changed it with a problem. One leg of the element bent at about 45 degrees from the vertical and made it difficult to remove.

It now heats to a very acceptable temperature and is still nice & hot after five hours.

My thanks to all who gave their advice.

Thank you.