Immersion heater not heating water, AGAIN!!!

[DeanR32]

Morning PH

I've got another problem with my hot water again. It's supposed to heat overnight (as you know), but in the morning it's like warm at best.

During the evening over the weekend I set the timer to heat up so I could see if it gets hot at all. I started beating the water, and 10-15 mins later, it started running through the tundish luke warm.

I'm away at the moment for work, so my missus called a plumber to come poke about. He set the water to heat as normal, through the night, and called my missus to ask if was hot. Of course it wasn't, so he said he will order a new thermostat and fit it Monday.

Is he right? He said the water is getting way too hot and getting released through the tundish, but it was only luke warm when I felt it. It could only have been heating for 15 minutes max.

Any suggestions from the knowledgeable fonts on PH?

[DeanR32]

Cheers for the replies

We have had a problem with the expansion vessel before. A couple of months ago it was full of water. A pal of mine (qualified) emptied it. When I checked it (Sunday) it was still as light as it was when he emptied it.

I'm certain the water is starting to heat, but something is letting it release through the tundish luke warm.

Does this shed any light a bit better?

[DeanR32]

Cheers again for the replies

As there was a problem with the vessel, I think I'll get that changed anyway. My thought was that it was a faulty PRV, but there can't be much that could go wrong with that, surely?