[Aogos]

Hiya all,

Can anyone tell me, even a good guess, what might be happening here. We have an indirect boiler system (the hot tank refilling from the cold tank in the attic). I recently noticed we had terrible condensation in the attic. We regularly go up there and have never seen any previously. After a good look around, it appears that the vent pipe is filling the cold water tank with a steady stream of hot water. This only occurs a short time after the heating is switched on but continues to do so until the heating is switch off. We've lived in the house for over 10 years and it's never happened before so we are a little concerned about what's going on. In recent weeks, I have changed a leaking radiator downstairs for a new larger one but did nothing more than shut off the water supply and drain the system to do so. I've called in two plumbers so far but both have failed to turn up so are at a loss what to do :(

As a short term solution we've moved the vent pipe to just over the water tank and then covered both with polystyrene. Now the steam from the hot water just vents outside so at least the attic is no longer getting condensation.

[NorthernHeat]

I'm not real sure of your problem. I think the tank is an expansion tank, not a refill tank. Make sure it is not a loose, rusty or plugged flue pipe.