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.