Boiler Banging and then blowing out

[Squonk]

HI!

Wonder if somebody can help me diagnose what's going on with my CH - It's an open system, Gloworm Fulesaver UFB 40B (about 13 years old) in a 17 yr old purpose built flat.

Turned the CH on for the the first time this winter Wednesday (Water has been on all the time) - all ok. Came back in this morning after a night away to a cold flat and a noisy, hot pump.. (Grundfos 15/50)

Have had the centre screw out of the pump, impellor turns fine. Both the Control valvee seem ok.

Boiler had gone out - relit it and started HW, pump started to churn away, nothing heated up then after about 5 mins- 2 or 3 big bangs in the pipes and it went out. So now it's off and staying off until I get it looked at!

Opened 2 bleed valves by the boiler and on near the HW control valve - marked lack of pressure!

Obviously needs looking at by a pro but any ideas on what could be causing it? System not been drained for eons either..

Thanks!

 

[Gasguru]

Any water in the feed and expansion vessel?

 

[Squonk]

Hi

Yes, although can't see exactly how full it is.

 

[Gasguru]

Does any water come out of the bleed points and the centre of the pump.

 

[Squonk]

Thats the worrying thing - no!