Central Heating

[Russb45]

I Have a typical pumped heating system. The hot water is fine, heating is fine but the feed/expansion tank overflows. I have changed the float valve on the tank but this has made no difference. I just dont understand why the expansion tank keeps filling up.

Russ

[Hard@it]

Check your level of water in the tank when system off, water level should be no more than 80-100mm above outlet. Bend the ball lever to attain. If not then is the water warm or is it coming over the vent, heck pump direction, if on flow it should be going away from boiler if on return check location of cold feed it should be on the discharge side of pump. Another thing is to check overflow outlet position it may be too low !

Remember this tank does not have to be full it is only a top up

[pilotlight]

Russ, If the problem has only shown recently, after having no problems, there is a possibility that the coil in the hot water cylinder has developed a split. This will cause the water level in the expansion tank to try to rise to the same level as the domestic tank.

Cheers.

[Hard@it]

see your other post