DIY Doctor UK DIY Forums

My feeder tank for the central heating has started to overflow, this appears to have a vent pipe I assume from the cylinder. I have isolated the feed to the ballcock, to ensure this wasn't dripping in. There is another open ended pipe feeding into this tank. I am not sure what this is but assume it some form of relief fromt he cylinder, can anyone point me in the right direction,

Thanks

There will be two vent pipes in your roof. The one of the CWST comes from the cylinder. The one over the F&E tank comes from the primary circuit.

It sounds as though you are experiencing "pumping over". It could be due to any one of a number of factors:

1. CH Pump Speed Too High

Try turning it down and see what that does. Note this will only be a temporary solution.

2. Blockage In Pipework

Needs flushing out if it's sludge or if it's a magnetite deposit it'll probably need that section of pipe cutting out and replacing. I'm afraid you'll need a professional for this.

3. Feed and Expansion Configuration Incorrect

Low chance of this if it's a recent occurence but if so needs to be fixed.

4. Vent Pipe Too Low

Needs to be raised.

5. Boiler Stat Set Too High or Gone

Boiler overheating.


The water coming out of the vent pipe is only a symptom and not the problem. It's important that this is fixed because all you are potentially doing is drawing aerated water back into the system which causes more corrosion which causes more sludge and also wastes a vast amount of heat and fuel.

Whatever the answer is you are going to have to get someone in to look at it for you. This isn't a DIY thing if you don't know what you are doing.

Hope this is of some help.

Cheers

Thanks roseberry for the reply,

I have now investigated further, I believe I have a pressurised hot water system and a vented central heating system.

The header tank has been fully isolated and i have checked that it is not filling up from the vent pipe, it is filling from the bottom, i.e. the feed pipe to the central heating system.

Is this pumping over?

thanks roseberry

I thought it was my hot water cylinder overflowing, I now know that is not and that the header tank is filling up from the bottom,

I have a pressurise hot water system and a vented central heating system. the central heating system is not filling the header tnak through the vent pipe, I have checked this thoroughly

I beleive this may pumping over ?

anyone know what my options are.