DIY Doctor UK DIY Forums

I'm not sure exactly where I should post this so I'll try the obvious place first.
The immersion heater in the top of the storage tank seems to have failed and I intend to have it replaced however I have noticed that there is another red circular cover at the bottom of the tank which looks exactly like the immerser fitting on the top except that there are no cables to it. I would be interested to know what this might be.
:?

Another immersion heater.

It is not unusual for a cylinder to have two.......(at least a few years ago)


The one in the bottom would be used if you wanted a lot of hot water, the top one for smaller amounts.