gas boiler adjustment

[Steve]

We recently had BG out to replace a filling loop on our Worcester electronic 9.4. While the engineer was here, he tinkered with the boiler itself, and ever since, every time I turn a COLD tap OFF, the resulting increase in pressure causes the diverter valve (brand new last year) to actuate as though someone's turned on a hot tap. This is what the boiler sounds like anyway. I understand how this works - the increase in pressure when the cold is turned off forces water through the diverter valve/heat exchanger/flow switch into the hot side, forcing the boiler to think the hot water is on. Our taps are quarter-turn, so the increase in pressure is sudden.

Is there anything I can do? Or should I get BG out to fix this? Will it harm the boiler?

TIA

 

[bster]

non return valve or surge arrester

 

[Paul Barker]

It does no harm, boiler won't ignite. check valve can fix it but adds noise to the system which may become worse than the insignificant problem you now have that many combi owners around the country suffer unaware or in silence..

Best cure is a domestic hot water cylinder.

 

[ChrisR]

If you have any little-used hw taps, run them for a while - could be air in the pipe.