Worcester Greenstar HE combi fault?

[Bucko]

I have a Bosch Greenstar HE35 plus boiler (3 years old) and it’s a fantastic bit of kit.
However I wanted to heat the lower floor radiators this weekend so shut off the top floor radiators and ran the heating. All was fine for a few hours but then the boiler started to make a loud roaring noise similar to an aircraft taking off in the distance. This noise is produced when the burner fires up and the fan speed increases to run the burners to full. Even when just heating domestic water. There is a little vibration on the fan PCB but not enough to make this noise. Any clues on what has happened with proposed solutions.
Thanks

 

[Agile]

How many times in the three years have you had the boiler serviced professionally with a proper check of the combustion setup using a flue gas analyser?

Tony

 

[Bucko]

The boiler had a service and check about 2 years ago by the Bosch engineer. He adjusted the levels at that time. They were slightly out then I remember him telling me that. He also did a mod on the ignition to make the holes larger to stop any corrosion shorting against the burner case.

 

[gas4you]

I don't like Worcesters but this sounds like you need a corgi in to check gas pressures/mixtures etc. I usually recommend calling in Worcester on a fixed price call out to fix faults.

Craig (clf) on here is one of our Worcester lovers and experts

Over to you Craig.

 

[clf-gas]

First proposed solution.

Open the upper rads again and run boiler, post back with what happens

 

[Agile]

The boiler had a service and check about 2 years ago by the Bosch engineer.

All manufacturers recommend that boilers are serviced every year.

In the case of band B boilers they are mostly very stable and many will go for 2-3 years between services.

Band A boilers should have at the very minimum an FGA check but many have issues with seals and should be carefully checked every year.

Tony

 

[Bucko]

Open the upper rads again and run boiler, post back with what happens

I did this as I thought this may the problem with water circulation. It made no difference the noise was still there. I did wonder if I had forced more water around the lower radiators stirring up dirt and this has got into the heat exchanger. Would this cause this noise?

 

[corgiman]

Agile is right you most likly need to get this boiler serviced PROPERLY ASAP

 

[gas4you]

Agile is right you most likly need to get this boiler serviced PROPERLY ASAP

Well pigs can fly. You agreeing with Agile

 

[corgiman]

I often Do Gas

He is like softus and annoyingly correct most of the time

Dont you just hate em

 

[clf-gas]

Open the upper rads again and run boiler, post back with what happens

I did this as I thought this may the problem with water circulation. It made no difference the noise was still there. I did wonder if I had forced more water around the lower radiators stirring up dirt and this has got into the heat exchanger. Would this cause this noise?

Ok a few different things could be the cause, and as you rightly said sludge may well be a key player.

Though my thoughts lie with the gas valve and fan flue. You will need an engineer, I would advise Worcester engineer. This aint a problem to fix over postings and threads.

 

[Bucko]

Do I assume from this that the conclusions are that it is possible that the gas mixtures would change in a matter of an hour and also that incorrectly set mixtures could cause this level of noise in the burners?

 

[Bucko]

Thanks for your advice Craig much appreciated.

 

[corgiman]

what about the rest of us

what are we scotch mist???

and yes it can

 

[Bucko]

Sorry

Thanks to you all
I will let you know the outcome