Water pressure/leak testing without disconnecting boiler?

[Donkmeister]

I've put in new pipework for a new bathroom as well as replacing some existing pipework that was in the way of building the bathroom. I would like to test my joints before I start screwing boards down, and have borrowed one of those pumps with a tank of water, hand-pump and gauge.

I had my heating system replaced in the last year and now have a Worcestor 38kW combi boiler. This has an isolator on the cold water infeed but does not have an isolator on the DHW output and there isn't an isolator elsewhere.

Is it safe to pressure test the hot side of my system with the boiler taking the pressure? If so, what pressure is safe?

NB none of my joints are leaking under mains pressure, however with lots of building in the area and our water mains being upgraded soon I'd rather know there is some headroom in this!!!

 

[John D v2.0]

Have a look in the boiler manual, they always specify, but it can probably take 10bar.
However consider that you'll be stressing the joints there as with elsewhere, so it's possible to find new leaks in old pipes.

Are you sure they're increasing your water pressure? Normally they would just add capacity, unless you're suffering from low water pressure at the moment, I wouldn't expect a particular change. What's your current mains pressure?

 

[Donkmeister]

Have a look in the boiler manual, they always specify, but it can probably take 10bar.
However consider that you'll be stressing the joints there as with elsewhere, so it's possible to find new leaks in old pipes.

Are you sure they're increasing your water pressure? Normally they would just add capacity, unless you're suffering from low water pressure at the moment, I wouldn't expect a particular change. What's your current mains pressure?

This is going to sound silly... I bought a pressure gauge a while back and forgot about it until I read your response. I've just checked... 4 bar static, 3 bar when the shower in the old bathroom is running full whack. That sounds healthy, so I doubt I'm getting a pressure increase when they upgrade the mains then!!!

Thanks John.