Recent content by lankyT

Yes, and even if there is a fault, the heating water can't get into the domestic hot water, only the other way round.

That's what I was thinking. Maybe the odd drip of condensation but that's all. And if there's a fault it's good if the overflow runs.

I'm just basing this on logic, not experience - but I would have said no, as long as it's only very small amounts, because it will only replace the water lost by evaporation, which would otherwise be replaced by the ball valve opening.

Isn't the point of an overflow to run when there IS a fault? But my question is does it matter? Will enough water come out of the vent pipe to cause am overflow? I would have thought only if the boiler is being continually overheated, and then a warning from the overflow pipe might be a good...

The only problem I can think of is that it could cause the overflow to run when there's no fault.

Due to lack of space the header tank for a hot water cylinder is about 5m away, but the header tank for the boiler circuit is directly above it. It's a gravity feed from a solid fuel backboiler. Is there any reason not to run the vent pipe from the hot water cylinder to the boiler header tank...