Water inside boiler casing

[Dan S. MacAbre]

Last time I looked inside our old Thorn Apollo (either the thermocouple ot the top socket needs replacing every five years, or so) when I took the inner metal case off, it looked like water had been running down the inside for a long time. My first thought was that the heat exchanger gaskets needed replacing, but our CH water is usually dark brown (even though I put inhibitor in every other year), and there was no brown stain as usually happens on the odd occasions that our CH water manages to escape. But I can't imagine anywhere else that it might come from. Is it normal for the gaskets to need replacing after 30 years? I wouldn't be surprised. Could it be condensation? We've started to go to Rome every February in the school holidays, but I'm not sure that the pilot light would cause that much moisture, given the ventilation from the flue.

[stuart noble]

We had a similar thing and the WB engineer had no idea where it had come from. Driving rain blown back down the flue? Doubt it. It dripped on the pcb and buggered that so I was not best pleased.

[Dan S. MacAbre]

It's always dry when I look, so it's not there all the time. Just rather odd. I did think about rain blowing into the balanced flue, but it would have to be very windy indeed, and the jacket is sealed with a gasket anyway, which would resist it being blown in.

Oh, it might be from the window cleaner who uses a long brush that has water pumped into it, and it goes everywhere. I can imagine that some would land on the outer bit of the flue and run in. Perhaps.

[Brian Reay]

I'd think condensation is unlikely- you need a cool surface. I'd be surprised if even the case was cool enough.

I'm afraid, given the age of the beast, I'd suspect a leak. Hopefully not in the exchanger (been there).

In the past, I've seen different colour (or no colour) to the trace left by leaks in a system. I'm not sure the lack of colour is significant.

[Dan S. MacAbre]

Me too, but that's why I mentioned we were away for a week each February. It's pretty cold by the time we get back :-)

I think I'm just going to have to wait until it's really obvious where it's coming from. Like crusty deposits building up, or something. Or maybe run it for a day with the boiler off. Too cold for that now, though :-)