Disconnecting water supply to Worcester Bosch Greenstar boiler

[terry.shitcrumbs]

Hi. I want to fit a lever-operated ball valve to the mains water feed to my boiler. When I chop the feed pipe and fit the valve, inevitably, I'll end up introducing some air into the pipe. Does anyone happen to know whether o n modern boilers, this is likely to cause a problem?

My intention would be to turn the boiler off before starting the work and t hen leave it turned off while I purge the air by running nearby hot taps. I 'm probably being over cautious, but I wondered whether it might be the cas e that modern boiler heat exchangers have such fine passageways for the wat er that air is apt to get stuck, thereby requiring a special protocol for p urging. I could imagine that running the boiler with air bubbles in the hea t exchanger might cause localised boiling and damage to the unit.

Thanks for any advice.

Terry.

[David]

As long as it is recent you should be fine.

Our recently (3-4 years?) installed WB Combi has a start up purge program which it runs before firing up after it has been powered off.

If you run water through the hot taps before firing the boiler up that should clear any major air out.

Cheers

Dave R

[John Rumm]

With most combi boilers the mains cold water feed does not go through the main heat exchanger anyway - but through a secondary smaller plate heat exchanger that is heated indirectly by the primary system water being diverted through it rather than directly by the gas burners. So there is no problem with air on the hot water side of the secondary heat exchanger.