Worcester Greenstar Ri HEADACHE!

[SlimD]

Hello,

I'm hoping that some of you mosre experienced guys can help me. I qualified and got Gassafe this year and it's been a steep learning curve as I'm learning something new with every job .

However, my in-laws Greenstar has me baffled. It starts to fire up but doesn't get past the 45 second stabilisation period. Instead after about 30 secs it makes thumping and hissing noises then the green light goes out and it waits a while before trying again.
It's on a Y-plan system and I get the impression that there's not enough water flowing through it and it's over heating the water, hence the hissing & banging noises. The pump had seized so I replaced that thinking it would cure it, but no. I've also manually opened the 3 port valve in case that was stuck and restricting flow to the boiler.
It's probably something pretty obvious but it's been a long week and I'm tired and fed up with scratching my head so would appreciated any suggestions from anyone who's familiar with these boilers and can put me out of my misery.

Thanks in advance.

 

[tamz]

Its circulation or lack off. Either pump or air lock. Pretty simple to suss out. Did you bleed the heat exchanger correctly through the hose on the top of it?
Do it when its off as i once had a nice steam flash burn up my arm off one.

 

[SlimD]

Been trying that and it's making no difference. Just blows out a bit of water, air and steam then steady stream of water but next time the boiler does same as before. I've bled the pump too.
Blocked heat exchanger maybe?

 

[SlimD]

It's definitely circulation (or lack of) related but I'm still head scratching.

 

[tolly]

check for blockages where the fill and vent join, you can do this with a magnet.

 

[tolly]

also you said you changed the pump, did the pump valves open back up ok if you used them?

 

[SlimD]

Tried that too, nothing. Magnet not sticking.

 

[mfgs]

Completely drain the system and refill, sounds like an airlock.

 

[Last Plumber]

I cant remember if there is a filter on the return on these but if there is it will need checking.

 

[SlimD]

Sorted. One of the valves on the pump wasn't open properly. It was sticking and, being tired, I mistook it for fully open. It's fully open now and problem solved.
Thanks very much for the help everyone.

 

[Last Plumber]

Sorted. One of the valves on the pump wasn't open properly. It was sticking and, being tired, I mistook it for fully open. It's fully open now and problem solved.
Thanks very much for the help everyone.

Well thanks for letting us know. All to often people just swan off once it's solved and you never hear from em again.