In message , at 12:48:37 on
Fri, 27 Nov 2015, e27002 aurora remarked:
My limited experience with combi boilers is that they are far from
reliable.

I have experience with precisely one, and it has been as reliable as
one might expect a system boiler to be.

How many have you experienced, and how old? The technology doesn't
differ that much from a system boiler. It's just that if it fails
there is no hot water backup.

One, well I did say limited, :-). And, its age was, to me unknown.
Before I bought this condo, I rented an apartment here in town for two
years. It had a combi boiler, it heated the water for the radiators
and instantaneously heated the water for the shower and faucets. Twice
during my stay I called out the repairman because the hot water supply
failed.

The worst one we had was in a rented house, and the hot water was out of
action for three weeks (in February). British Gas, who had a maintenance
contract, called almost every day, and were simply unable to work out
what to do with it. Eventually they called out someone from the
manufacturer.

For three weeks we had to boil water in pots on the cooker to wash or
have a bath. The managing agents were useless; as far as they were
concerned it was BG's problem.
--
Roland Perry