Hot water in expansion tank

[duncwilson]

Hi -

Please please help because it it a bit of a worry !!

We have a combi (open system) and the expansion tank in the loft is hot & i mean hot !!

Should the expansion tank contain such hot water ??

If not - what could the problem be ??

thanks

 

[mmalone]

could be pumping over. check your pump speed, could also be a blockage but check pump speed first and turn down if required..

 

[duncwilson]

Thanks very much for the advice.

I will have a play with the pump speed and see what happens.

Only think that seems to confuse me is that :

1. this situation occurs even when central heating is off & i am just using boiler for hot water (Worcester Heat Slave open vent Combi).

2. the water is not pumped to the header tank - the header tank merely exists as an expansion vessel for central heating system.

The boiler is about 30 years old - do you think it is worth my while desludging the system ??

 

[duncwilson]

I forgot to add :

Central heating works fine, everything works OK its just that expansion vent pipe coming out of boiler is very hot and header tank is full of hot & steamy water which i am sure is not normal

 

[oilman]

....................
1. this situation occurs even when central heating is off & i am just using boiler for hot water (Worcester Heat Slave open vent Combi).

................


The boiler is about 30 years old - do you think it is worth my while desludging the system ??

Would this be an oil combi?

when you are demanding HW, the boiler may be overheating, this could be a blockage, and it could be a faulty thermostat. Can you control the boiler in HW mode by altering the thermostat?

 

[duncwilson]

Hi oilman - a friend in need is a friend indeed - a friend who knows about plumbing is better !

Yes it is an oil boiler

I can alter the temperature of the hot water with the dial on the front of the boiler and this works fine - when i turn it up the burner starts, when i turn it down the burner stops.

Question for you - the vent pipe into the header tank is under the water in the header tank - should it be above ??? Could this be the problem ?

Thanks