radiators getting hot with hot water only selected

[pb21]

Hi

We just bought a house with a gravity fed back boiler. The back boiler is a baxi bermuda 552.

The boiler is on the basement floor with the water tank above it on the ground floor.

the radiators from ground floor to top floor get hot when only hot water is selected on the programmer.

I thought there might be a valve that operates to stop the hot water expanding into the radiators to stop this kind of thing but I cannot find the valve.

I am only a novice so an experts opinion would be most welcome.

Regards in advance.

Peter

 

[AD]

I have a Baxi Bermuda 552 system in my house. ( Currently not working, needs a replacement back boiler. If anyone knows a cheap replacement let me know )

Anyway when ours was working the same thing happend. Heat the water up and the radiators get warm. All i think that happens with this system is the back boiler heats the water up and circulates around the system, now when you have the radiators on it turns the pump on. So even though the you only have the water on its only the pump that doesnt operate.

Correct me if im wrong, just trying to let you know it happens on someone elses Baxi Bermuda ( or at least did )

-=AD=-

 

[oilman]

I recall similar circumstances when we used to have a solid fuel boiler. The boiler was on all the time, and the radiators got warm. The radiators got hotter when the pump was switched on but it sounds much the same as yours.

 

[corgiman]

I think the problem is either

1. the Aniti gravity valves is stuck
2, ther is no anti gravity valve

You need to have a operational gravity valve to stop this

it is like a one way valve but not as strong and opens when the pump operates, if you have one replace it if you dont put one on

 

[pb21]

excuse my naivity if there is no anti grav valve fitted would the problems have been there from the beginning of the boilers installation? I cannot find the valve will it be a part of the boiler or located externally?

regards

 

[corgiman]

Not necessarily mate

Have been out and fitted anti grav valves to very old systems that have desided to need one.

It will be fitted on the central heating circuit on the positive side of the pump

 

[COG]

Its been 18 years since i fitted a 552 but didnt they have a valve fitted with the combined injector tee on the return, which used to stick and block with sludge

 

[corgiman]

I dont think so mate as I have had to retro fit several

Mind if this is the case it is no longer a DIY job as the fire will have to be removed.

Call an engineer PB sorry