No, I haven't gone and bought a combi :-)

A friend has a Worcester 240 combi boiler, about 9 years old. The
pressure started dropping a week ago, and it now needs topping up
several times a day. Further investigation reveals that it is losing
water from the drain that goes to the outside of the house. This isn't a
condensing boiler.

I have zero experience with combis. Any pointer to what this might be,
where to start, etc.? What is this drain? Why is it there? What does it
connect to? What could be causing the water loss?


TIA


--
Grunff