Boiller losing pressure

[pyardley]

Hi,

I've got a Valliant combi boiler in a basement flat. I've been seeing the pressure drop to zero. It used to take about a week but now it drops to zero after about 2 days. I refill to 1 bar and it drops to zero again.

I'm guessing its a leak, but is there anything I can test I before getting an engineer in?

Many thanks

 

[Rogue Trader]

check the expansion relief pipe from boiler (the one that goes to outside & is open ended) Check to see if it,s dripping. Also check all visible pipework for signs of water leakage

 

[pyardley]

thanks - I will attempt to check the expansion relief pipe. The problem is finding it (new flat with everything boxed and hidden away)

Certainly no leakages on any of the pipes I can see.

 

[Gasman1015]

Pressure the boiler to 1.5 bar, then close the flow and return isolation valves,
leave boiler switched off for a couple of hours, if pressure drops then boiler leak otherwise a system leak.

 

[pyardley]

Thanks for this tip - do I need to switch the boiler completely off (i.e. no hot water)?