Worcester Greenstar Junior 28i issue

[Kewat66]

Hi All,

I had look at at Worcester Greenstar Junior 28i today that stopped working. Boiler wasn't producing any heat or hot water. When assessing the problem a strong smell off gas was found coming from the gas valve. The reset button was flashing 1 per second. The boiler was trying to function on hot water but when it was put on CH it sounded as if it wanted to take off!
just trying to get pointers i am in the correct area but if gas valve blocked or not working would this cause these symptoms?

Thanks

kewat66

 

[Ermintrude]

Was the fan working?

 

[diamondgas]

What did you 'sniff' the gas valve with? These are zero pressure governors so I'd be worried if it were leaking without a fan running!! However if the general smell was within the case chamber and the fan is running then you'd need to know if the ignition sequence was being completed IMHO Ignition then noise could be a couple of things ... but ignition and a smell of gas is worrying... Bit more info on what you've done so far may help us help you kewatt66

 

[Kewat66]

Yes fan working fine

 

[Kewat66]

I put my gas sniffer nest to the gas valve and it went nuts, but yes the fan was working at this time.

 

[SafeGasInstall]

where was gas leaking from ? test point left open ???

 

[Kewat66]

No checked test points and these were closed. When it was running through the sequence there was a strong gas smell when you stepped back from it.
When the boiler was idol, sniffer picked nothing up and no smell of gas?

 

[diamondgas]

These are premix burners so anywhere on the positive side of the mix has the potential to 'leak' out the mixture. With the case off there's also a chance that 'wind' from outside can blow back unburned mixture into the chamber? did you get ignition?

 

[Kewat66]

Yes got ignition for a few seconds on hot water, then went off. It tried to ignite on ch but just ran through the start sequence, then lots of noise in the burner chamber. Pump was working as you could hear and feel the water rushing around.

 

[Kewat66]

Then went into reset and red light flashing 1 per second. Gas was smelt as it was trying to ignite.

 

[diamondgas]

Then went into reset and red light flashing 1 per second. Gas was smelt as it was trying to ignite.

I'd be looking at gas supply, ignition gap and/or flueways including possible condensate blockage ... I don't get to work on a great deal of greenstars but aren't these the ones with the flap that sticks in the burner mixing chamber? Not sure if that'll give the issues you're talking about ... Also heard of the flaps snapping off and ending up on the inside of the burners if it is the type I'm thinking about...! Maybe someone can verify that though? ...

 

[P J F PLUMBING]

I went to service one of these today took case off smell of gas around the gas valve !!! Put sniffer around def gas leak test points both tight but leaking called worester they said gas valve needs changing !! 2 years 5 day old out of warrenty !! Unreal Thank worcester for that

 

[Kewat66]

Thanks for that. Have got new valve ordered so hopefully will sort it.

 

[P J F PLUMBING]

Replaced the one from today new valve all ok now

 

[diamondgas]

Thanks for that. Have got new valve ordered so hopefully will sort it.

Have you tested the valve for soundness Kewatt66..? An expensive piece of kit the custard has to pay for if it isn't at fault IMHO... Not saying it isn't, but a simple soundness test will verify if its passing or not yeh?