Frequently when I turn on the cold tap, I get hot water coming out of it for the first 30 seconds or so, it eventually turns to cold but it has been happening with increasing frequency of late. Shorty before we moved into the house a new boiler was installed? Any idea what could be causing this or is it perhaps an installation problem?

Is your water heater separate from the boiler? OR does the boiler do both?

As far as I know it's a combi boiler, have asked a few questions of both installing plumber and landlord and they say its just the pipes are run to close together, but I disagree as the water coming out is far too hot.

A bad check valve could cause that problem if it is a combination unit.

The check valve prevents the boiler from overheating the water doesn't it? Ie: the boiler does not stop heating!

The check valve prevents the boiler from overheating the water does'nt it? ie: the boiler does not stop heating!


A check valve prevents the hot water from backing up into the cold water line due to temperature/pressure differentials.