I have baxi back boiler have noticed hot water coming from over flow and the cold water header in attic is now full of hot water and heating making guggling noises only getting air out of system when bleeding rads any ideas.
Thanks

Dave, January 2009

Did you check the pump as there are usually 3 speeds on them.If it is on 3 turn it down to 2 and see what happens.If the thermostat was at its highest setting then it could have acted similarly to a boiling kettle and thats why it has been pumping over.Hopefully with the boiler stat on about 1/2 way and if need be the pump speed turned down a notch,you should be able to stop it pumping over.

Tony S, January 2009

Thanks tony where likely would the blockage be on cold feed have checked the pipe capped near the gate valve for air and water there is neither does this indcate a blockage somebody also told me that the thermostat on back boiler faulty can cause it to overflow the same do you agree when heating swithed of no water is coming from overflow i think the blockage awnser is more likely after finding no water or air at the pipe near gate valve.
thanks
Dave

Dave, January 2009

It is a possibility if the cold feed from the tank is blocked,also when the copper tank cylinder coil developes a leak it can cause continuos overflowing.

Tony S, January 2009

Thanks tony have check thernostat was up full i have turned it down prior to doing this the boiler has not fired up when switched on every thing was fine yesterday is it possible for the boiler to stop taking in water from tank and pump out via over flow

Dave, January 2009

Check 2 things.The first that your boiler thermostat is not too high as you may get rumbling noises which will be causing the hot water to pump over into the tank.The other is to see what speed your pump is set to.It may need turning down to a lower setting if this is causing the overflowing.

Tony S, January 2009