WB Combi 12/14 burner problem

[jackg]

Installed in 2004.
Serviced annually by the same man, OFTEC registered.
The burner is a Bentone
Black smoke started coming out of the exhaust about two weeks after the annual service in January.
Called the engineer, he replaced the burner nozzle.
Fine for a couple of days then black smoke.
Engineer came and said he had used a slightly different nozzle which is usually ok.
He turned the oil pressure up slightly and got the boiler to work ok with the same nozzle.
It was fine for a couple of days then black smoke.
He did not have the correct nozzle.
He came today to install the correct nozzle and adjusted the oil pressure.
It was fine for a couple of hours then black smoke.
Errr what next?

 

[Burnerman]

To get the full 14kW output the B9A burner should have (if its this one thats been fitted, depends on the age)
0.50 60deg ES nozzle
Fuel oil pressure 100 psi
CO setting 11.5%

I'm wondering if the engineer used a flue gas analyser to set up the burner?
There's a possibility that the air door box has moved (somehow) thereby restricting the air intake but thats unlikely! The approximate door setting is number 7.
Were the baffles cleaned inside the boiler, and the flue outlet cleaned likewise?
The thing needs setting up properly - its not working well even at the start, and then gets so bad thats its chuffing smoke. Not good!
John

 

[jackg]

To get the full 14kW output the B9A burner should have (if its this one thats been fitted, depends on the age)
0.50 60deg ES nozzle
Fuel oil pressure 100 psi
CO setting 11.5%

I'm wondering if the engineer used a flue gas analyser to set up the burner?
There's a possibility that the air door box has moved (somehow) thereby restricting the air intake but thats unlikely! The approximate door setting is number 7.
Were the baffles cleaned inside the boiler, and the flue outlet cleaned likewise?
The thing needs setting up properly - its not working well even at the start, and then gets so bad thats its chuffing smoke. Not good!
John

Not sure how he set up the burner.
When he serviced it he gave me a print out of the machine he used.
The top line of which reads: Test to 325-1.
I think it is a gas analyser as it has readings or flue temp, O2, CO2, CO and efficiency.

He cleaned the baffles but not the flue outlet.

 

[Burnerman]

It sure sounds like it, but haphazardly adjusting the pump pressure isn't the way to go.
Personally I'd give someone else a try!
John