Hot water overflowing in to central heating header tank

[mickymo]

Hi can anyone help I have a glowworm energy plus EP40B energy saver boiler with cylinder and water tanks that I serviced only two weeks ago as I was having problems with my central heating not working although the hot water was ok.
I changed the three way motorized valve as that is what I was told was needed but no it was not that I then found out it was the wirefree receiver at fault so I changed that and the transmitter.
all is working well now but when I went up in the loft I noticed steam comming from the central heating header tank on inspection there was also hot water running from the expansion pipe this happens when I have the hot water is on on its own also when the heating is on on its own and worse when both are on both togeathe the tank does not overflow it stays at the same level no matter how much hot water runs in to it.

Can anyone help thanks. Mike

 

[misterdubya]

You have a partial or full blockage in part of your heating system. The header tank is being used by the system as a 'bypass' for the blockage - hence it wont overflow as the water pushed into it by the open vent is travelling straight back down the cold feed and re-entering the system.

Can you post a pic of where the cold feed / open vent join the system (the blockage maybe in that area)?
Mr. W.

 

[mickymo]

Hi misterdubya.
Thanks for your reply I am new to this and do not know how to post a pic yet
where do you mean to take pic do you mean where the cold feed and open vent enters the header tank.
If I put in some anti sludge liquid in the header tank could that clear it
A couple of month`s ago I changed the cold water tank for a new one and all the pipes were connected like for like could I have unsettled something there. Mike