White Bloom on Blast tube of Kerosene Burner

[andyr123]

Hello. we have a Stanley 80 twin cooker with 2 burners in one for CH part, one for cooker part. I had it apart yesterday to clean out combustion chamber and noted that the blast tube on the CH burner had this white bloom on it. The boiler/cooker had a service nov 2015. Both burners on the cooker part and the CH part have both identical burners (i couldnt be sure of same jet size) but the Cooker burner has a black'ish sooty blast tube wheras the CH burner has this white bloom inside it (took picture) .
Going back to my old days when you could service your old cars without any diagnostic machines, if you took at the spark plugs and they had this white bloom on the electrodes it denote the car mixture was running too lean / weak and mixture had to be adjusted (by then a screw on the carb) so could it be the same thing on this CH boiler ? - could it be running too weak or have too much air to kerosene ratio? - just wondered what others think on here. Be great to get an expert on kerosene oil boilers advice. Thanks.


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[slapper]

Wouldn't worry about it, its just products of combustion. Main thing is that the burner is running correctly and free from sooting

 

[halfway]

I wouldn't consider that normal combustion residue. It is on the inside and outside of the tube. There is also soot on the fins and on the nozzle.
That looks like something unusual got into the combustion mixture.

The nozzle size and combustion settings should be in the report that you got with your 2015 service.

 

[Burnerman]

How much kero do you reckon to have burnt since the last service?
I've found that the blast tubes often have different deposits on these, and I've put that down to the cooker side not being used too often, or maybe only at a low temperature setting. Another issue is the differing flue gas passages on these boilers.
Either way, a flue gas analysis / fuel pressure check should determine what is going on.
Personally I've found the flue baffles to need much more frequent attention than on traditional systems.
John

 

[oilhead]

And you hope that your service engineer removed the very fiddly baffles in the boiler. I would have expected the blast tube to be cleaner than this.
Why did you feel it necessary to investigate the appliance?

 

[andyr123]

And you hope that your service engineer removed the very fiddly baffles in the boiler. I would have expected the blast tube to be cleaner than this.
Why did you feel it necessary to investigate the appliance?

Burner was making a whining noise, and 'crack' noise as it was heating up. took off the motor/fan off cooker burner (because we dont use cooker part) and put the motor complete with its blower fan (which was really clean due to hardly any use) in place of the CH burner motor/blower fan - so now got rid of the awful screech when CH burner starts up. still got 'cracking' noise there which I think may be either a bit of metal that cracks as the boiler heats up or one or more of the baffles cracking/banging as the boiler heats up - one day I shall have to take the whole lid off and have a look at the baffle(s)

 

[andyr123]

going back a couple of years back I took out the burner to clean the bottom of the combustion chamber of soot/rust/dirt and im sure when i looked at the blast tube it was of a black sooty colour same as the blast tube on the cooker burner. I cant think why its white on it now, apart from maybe the mixture is too weak/has too much air to oil ratio - still , even with this white bloom the boiler has no trouble firing up/ starting up and operating so i dunno

 

[Burnerman]

The whining noise would be the motor bearings.....dead simple to replace if you want.
I'd still say you need to get the fuel pump pressure and flue gas analysis checked if you want the thing as clean as possible (once the baffles and flue ways are clean).
John