Worcester Bosch Style 8000 Combi Boiler Steaming from the Flu and Whinning Sound?

mazibee

Hi Everyone,

I have a Worcester Bosch Style 8000 Combo Boiler and its steaming from the flu, ( Its 2.5 years old)

It has also started to make a whining sound when the hot water tap is closed  ( it used to make a sound when the hot water taps are  closed but that whining is an additional sound)

The boiler was serviced 2 months back.

Any idea what can be the reason?

Thanks in advance

NSG666

Steam is a by product of the combustion process so quite normal when the boiler is running. Is the whining definitely coming from the boiler as sometimes float valves whine as taps are closed and the sound transmits around the house? How long does the sound last? Does it stop if you crack a cold tap open?

mazibee

@NSG666

Thanks for your reply.

The steam from the flue does not seem normal,  as its too much,  as compared to when I notice from the neighbour houses.

I have made a video but I am unable to upload it here.

Yes, I have checked again last night and the whining sound is from the boiler

When the heating is on

When the close the hot water tap , its mixed w3ith the sound that used to come when the boiler is filling

That whining  sound lasts until the boiler filling sound last (after closing the hot water tap) for approx 40-50 seconds

I am non-technical, is there any circulating filling valve that can make that noise?

Thanks

BUFF

mazibee said:

The steam from the flue does not seem normal,  as its too much,  as compared to when I notice from the neighbour houses.

The amount of steam can vary according to how your boiler is set up & the ambient temp. You have a condensing boiler but is it running at the right flow/return temperatures to condense most of the time?
Also, generally when first switched on it will probably go straight to full power for a few minutes before modulating down to a lower level - this will also result in different levels of "pluming".

You can always call the company/engineer who recently serviced it.

Bendy_House

Hi Mazibee.

It's almost certainly as NSG says.

This is a 'condensing' boiler, so gains extra efficiency by extracting heat from the burned flue gases. A lot of water is produced by the combustion process, and in older (non-condensing) boilers, this was sent out the flue as invisible 'steam'.

Condensing boilers like yours cool the exhaust gases, extract a lot of that otherwise-wasted heat, and this has the effect of condensing the steam so that it's now visible - it's become water-vapour. This shows as a 'plume'. The plume is very much more visible in cold weather.

Why is there so much in your case? I think it's because you are looking at it whilst the boiler is supplying hot water? I don't know what power rating your model is, but let's say it's a 35kW jobbie. When your boiler is heating just your radiators, it's likely only running to provide 10, 15, or so kW of power - it'll vary according to demand. If you listen to your boiler at this time, it'll likely be making just a gentle hum or mild 'whoooo'..., and this will rise and fall according to demand, and the resulting fan speed. Look at yer flue - you'll likely see a gentle flow of plume wafting out, just like all your neighbours'.

Then you turn on a hot tap... The very powers of fiery hell are now unleashed - all magnificent thirtyfivethousand watts of screaming gaseous power. In other words, your boiler fires up at its max rating - the fan will whine at its top speed, and the plume will be ejected like a rocket blast.

I suspect all is quite normal. Your boiler is certainly still under guarantee, so I'd personally leave it until the next service and ask the fellow about it. 

mazibee

BUFF said:

mazibee said:

The steam from the flue does not seem normal,  as its too much,  as compared to when I notice from the neighbour houses.

The amount of steam can vary according to how your boiler is set up & the ambient temp. You have a condensing boiler but is it running at the right flow/return temperatures to condense most of the time?
Also, generally when first switched on it will probably go straight to full power for a few minutes before modulating down to a lower level - this will also result in different levels of "pluming".

You can always call the company/engineer who recently serviced it.

Thanks Buff.

Bendy_House said:

Hi Mazibee.

It's almost certainly as NSG says.

This is a 'condensing' boiler, so gains extra efficiency by extracting heat from the burned flue gases. A lot of water is produced by the combustion process, and in older (non-condensing) boilers, this was sent out the flue as invisible 'steam'.

Condensing boilers like yours cool the exhaust gases, extract a lot of that otherwise-wasted heat, and this has the effect of condensing the steam so that it's now visible - it's become water-vapour. This shows as a 'plume'. The plume is very much more visible in cold weather.

Why is there so much in your case? I think it's because you are looking at it whilst the boiler is supplying hot water? I don't know what power rating your model is, but let's say it's a 35kW jobbie. When your boiler is heating just your radiators, it's likely only running to provide 10, 15, or so kW of power - it'll vary according to demand. If you listen to your boiler at this time, it'll likely be making just a gentle hum or mild 'whoooo'..., and this will rise and fall according to demand, and the resulting fan speed. Look at yer flue - you'll likely see a gentle flow of plume wafting out, just like all your neighbours'.

Then you turn on a hot tap... The very powers of fiery hell are now unleashed - all magnificent thirtyfivethousand watts of screaming gaseous power. In other words, your boiler fires up at its max rating - the fan will whine at its top speed, and the plume will be ejected like a rocket blast.

I suspect all is quite normal. Your boiler is certainly still under guarantee, so I'd personally leave it until the next service and ask the fellow about it. 

Thanks, Bendy for the wonderful explanation.