Worcester-Bosch Greenstar 30CDi combi

[eddie7]

I have recently moved into a block of flats that have Worcester Bosch combi boilers to provide underfoor heating. If the hot tap is turned ON with the underfloor heating running there is a short sharp noise - a squawk that appears to come from the boiler - probably caused when the diverter valve operates. The boiler has been serviced and the diverter valve motor and the diverter valve have been replaced, but the noise is still there. Other residents seem to have the same problem.

Any ideas?

 

[AGAS]

probably caused when the diverter valve operates. The boiler has been serviced and the diverter valve motor and the diverter valve have been replaced, but the noise is still there.

if the diverter has been changed why do you think its still the diverter ?

 

[eddie7]

I don't, but it is the only thing that moves and changes the direction of flow of the water in the sealed central heating circuit.

I recorded the sound and sent it to the Tech Dept of Worcester Bosch and this is their reply. Does it make sense?

Thank you for the audio file, from this we believe this to be a part called the bearing plate which sits above the fan sticking.

 

[eddie7]

Got a reply from the Tech Dept of Worcester Bosch after sending them a recording of the sound made when the hot tap is turned ON. They are suggesting that it is a bearing plate which sits above the fan, and it is sticking. Does that make sense?

 

[AGAS]

you need a gas engineer to sort this problem out , indeed if that is the cause

 

[edvinpaus]

Does the boiler make a deep rumbling noise? This happened to me once before, I had to get a new Fan Diaphragm, or what Worcester boilers call a 'Bearing Plate'. Make sure to change it soon, because the initial onset of the rumbling and shaking can crack the solder joint.