Do non-return valves fail?

[jmkennedyie]

Greetings. New to this world so apologies in advance for info I didn't add, or added that I didn't need to...

10 yr old bungalow with oil burner (non pressurised, small open tank in attic) integrated with back boiler behind a fireplace. Two worms in hot press, one from back boiler (joined to attic), one in parallel with rads to get h/w direct from oil burner.

Plumber came yesterday as h/w would not circulate and boiler cut off after a few minutes. Pump fine. He removed any air between attic tank and hot press worm, did some bleeding beside the boiler. Maybe other stuff. System working good-o when he was leaving . I tried again a few hours later - but boiler wouldn't come on . Can hear pump, and rattle coming from non-return valve (?) beside the boiler. When I turn off system, sounds like bubble rising from hot press area.

Any ideas? Do non-return valves fail (intermittently?) ? Something loose in pipe jamming the valve? Would a complete drain/refill of system make things worse, or better to get plumber to check out the rattle in case I move it? Any special notes on refilling a system to avoid trapped air?

Any help much appreciated!
- John.

 

[corgiman]

if your not 100% happy in getting stuck in mate my advise is DONT call him back

As to your question yes they do so pop a new one in

 

[oilman]

if your not 100% happy in getting stuck in mate my advise is DONT call him back

Don't understand the logic of this

 

[corgiman]

Sorry Oilman I meant if you are not happy with draining down your central heating system then I would advise against doing it, as if you make a mistake then your lack of confidence may make it worse thats all

I speak from experiance.

 

[jmkennedyie]

Confidence draining it is not a problem - did it before and system worked since. And it was all working dandy when plumber left yesterday. Just don't want to remove any evidence in or around the valves. Sounds like they could be the culprit, so I'll get d professional back and pop them out - I don't have the knowledge, kit or confidence to replace them .

Thanks for the time - I'm sure yee are all flat out this time of year.