Water boiling in header tank

Banjo Carney

Hi I've got a duel heating system, oil and solid fuel. The solid fuel system hasn't been used this winter yet only the oil.

I went into the attic earlier to get the Christmas decorations and the water was boiling in the header tank. There was steam coming through the insulation cover.

What would be the most likely cause of this. Thanks in advance.

Wearb

Make sure your boiler is cycling on the boiler stat.

Also check that tank has water in it and ballxock not stuck.

Have you done any work on the heating recently.

Banjo Carney

Thanks for your reply. About a month ago when the boiler started it was tripping the switch. I was away at the time and it was sorted by a plumber. I think it was the pump he changed I'd have to check with my wife.

Wearb

What switch?

Tails142

I would think it's probably not boiling? Did you check the temp with a thermometer?

Your new pump is probably set too high and it is circulating hot water up into the header tank which would be at 70 degrees or whatever the stat on your boiler is set to.

Pumps normally have three settings. I think the advice, particularly with a header tank set up, is to set it to the lowest setting, see if that heats all your rads properly and if not then go to '2' and so on. This will cut down on 'pitching' - have you ever noticed water coming out the overflow from your header tank?

Banjo Carney

https://www.boards.ie/discussion/comment/121492708#Comment_121492708

The trip switch on the fusebox. I think water from the pump was leaking on to electrical connections

Banjo Carney

https://www.boards.ie/discussion/comment/121492737#Comment_121492737

Yeah maybe not actually boiling but hot enough that there was steam coming out through the cover.

Now that you mention it there was water coming out the overflow a couple of years ago. If I remember rightly the hot water cylinder was changed at that time.

John.G

What pump and setting (photo?)