Could one leaky valve cause pressure to go in one day?

[bpowell555]

Sealed system has lost all pressure twice over the last couple of days, and today within 12 hours. I would have thought this would make a noticeable leak but the only one is a slow rad valve that till now hasn't caused a problem. Could that be it or would I expect to see at least a puddle?

Or should I look towards the expansion vessel or boiler?

Pressure went from 1.4 to zero from this morning to this evening...

Cheers!

 

[Terrywookfit]

Fasten a plastic bag over discharge pipe to check!!

Also check exp vessell as FAQ!

 

[bpowell555]

May have answered my own question - looked again and the leaky valve was p!ssing water. It turned out the screw in top part was undone, so tightening that stopped the leak and the system is ok now