DIY Doctor UK DIY Forums

Heres an interesting but annoying problem. Our immersion heater is heating the water in the tank but only seems to heat about a sixth of the water because running the tap for more than a couple of minutes the water is progressively cooler when it was hot before. the heater has been left on for about an hour which normally was enough to keep the water hot for the rest of the day.
How can this be?

There are different lengths of element and if a short type is installed, only the top few inches of water will be heated.

Either the wrong element has been fitted, or the cylinder will not take the longer version. Check any labels on the cylinder which should state the maximum length and compare that to the element fitted.

Often in indirect cylinders, the immersion is only designed as a backup emergency source and only a small amount of water is heated.

Hi,

Perhaps the element is breaking down= replace it.

Hth

if it used to work as you say, I suspect it is scaled up. if it has always been like its probably the wrong size..... if you have a n indirect cylinder it should be ised as a backup only really anyway.

Is there any other method of heating the water except the immersion? If so it may be that the immersion is working as well as it always has - it's the other methodthats the problem.

If you decide you do need to replace the immersion heater and you are in any way uncertain I'd really recommend getting someone in - particularly if you don'y have the correct tools. There is a very real risk of damaging the cylinder if you don't know what you are doing.

Cheers