oil boiler

[ringy1]

hi i am just servicing a oil boiler, firdbird popular 90 the burner is a riello 40 g3b does anyone know the co2 percentage for this burner as i dont have a burner manual thanks.

 

[Burnerman]

I'll try to dodge the (friendly) blows that are sure to come my way but look for a smoke reading of zero to trace, and a combustion chamber application of between 12% to 13% CO2 as a general start level. Be aware that flue temperatures will vary due to excess air increasing the flue temperature for example. Cheers John

 

[Boilerman2]

Set CO2 at No More than 11.5 - 12.0%, as you will then leave the boiler with an excess air of around 38 -40%, which will give a margin for error to allow for changing weather and wind conditions which will effect the flue pull etc 13% and you could reisk having to go back to a sooted boiler (ouch)

 

[Terrywookfit]

Set CO2 at No More than 11.5 - 12.0%, as you will then leave the boiler with an excess air of around 38 -40%, which will give a margin for error to allow for changing weather and wind conditions which will effect the flue pull etc 13% and you could reisk having to go back to a sooted boiler (ouch)

I will second this advice.

 

[ringy1]

i was just servicing it a while ago and oil pressure is at 8 bar but when i adjusted the damper because excess air was at 102 and im trying to get it between 20 and 50, it goes down to about 60 and my analyser beeps that it detects that co is too high how can this be when excess air is well over 50? and i tryed adjusting my oil aswell but i am getting no joy

 

[Boilerman2]

You really need to be looking at Co2 as the leading factor, Excess air can be misleading as it is effected by many factors such as air ingress through poor seals, are you measuring the combustion gasses Upstream of a Draught Stabilizer? as this will give very wobbly readings,

11-5% CO2 should be easily obtainable on a Popular, with a CO 0f no more than 10 - 20PPM

 

[Boilerman2]

Oh! forgot to mention, have you repalced the Oil Nozzle with one of the Correct Capacity, Spray angle and Spray type?

if the Nozzle is worn you will never be able to set the Burner up

 

[ringy1]

yes nozzle is changed its a 0.50usgh 80S. and there is no stadilizer and CO2 was reading in around 9

 

[oilman]

That CO2 is miles too low. The CO2 starting point is say 11%. Then check for smoke. If the smoke is zero, increase CO2 to 12%. If still no smoke, I would leave it at that.

Another frequently forgotten figure is FGT. If this is high you need to make adjustments.

You are setting up the boiler. It will not always be possible to achieve manufacturers settings. The installation configuration is not likely to be the same as the original test set up, so the settings wont be the same.

 

[ringy1]

cant get the CO2 up any higher than 9 without CO level going to high could it be the nozzle i changed nozzle bout 2 months ago but did not replace nozzle prior to FGA today

 

[oilman]

You'd better check the fuel supply.

 

[snb]

silly question but you have got your analyser set for light oil and not nat gas.

as said check FGT as this often requires the oil pressure to be reduced to achieve this.

If you are still having trouble then it indicates that the volume of air is not great enough. this could still be dirty fan or failing motor.

 

[oilman]

Or a blocked flue.

 

[ringy1]

damper was set at 2.2 and oil pressure at 8 bar. O2 is 10.9 CO2 is 7.4 flue temp 192 EFF gross 82.0 XS air 108.5 cant get CO2 passed 9 without CO level going to high. ill check the flue for blockage and yes analyser is set on light oil

 

[Boilerman2]

I'm not suprised with a 0.5 usg Nozzle a 26.4 Kw/h Boiler will be Grossly UNDERFIRING, as I previously stated a 0-75 usg at 9-0Bar for Class C.2. Oil would be more approriate, you should then find that you can obtain the recommended 11.5%