FGA

[martineire]

can anyone tell tell me i just serviced a firdbird popular 90 boiler today its about 20 years old. when i was doing my FGA all my reading were in range O2 was 5.4 CO was 5ppm CO2 was 11.5 RATIO was 0.0000 XS air was 34.6 EFF gross was 81.8 but the flue gas temp was very high 315 degrees when this should be around 210 degrees. Why is this so high when my oil pressure is at 8 bar so i cant really drop it much lower than that. Boiler stat was set at 75degrees would this have that much of a bearing on the matter.Any help what do ye think

 

[Terrywookfit]

Did you remember to refit the baffles?

 

[martineire]

Did you remember to refit the baffles?

Of course that goes without saying

 

[holty]

5ppm seems way to low.

 

[martineire]

Your ment to have CO as low as possible, it is carbon monoxide after all

 

[holty]

really. i never knew that

 

[martineire]

5ppm seems way to low.

You said it

 

[bengasman]

Your ment to have CO as low as possible, it is carbon monoxide after all

And??
As long as you don't intend to sniff it, it is fine to blow it into the atmosphere.

 

[martineire]

Your ment to have CO as low as possible, it is carbon monoxide after all

And??
As long as you don't intend to sniff it, it is fine to blow it into the atmosphere.

Exactly thats my point. Holty said it was way too low its ment to be low thats what im saying anyway if you read my original post all my reading are within there parameters except my flue gas temp is way too high when it should be around 210. does anyone has a theory why this may be, when my oil is set bout 8 bar

 

[sooey]

I don't do oil, but has it got the right nozzle in?

 

[Agile]

If its burning correctly, and that seems to be the case, then a high flue temperature indicates a lack of thermal transfer into the water.

Is the flame side of the heat exchanger really totally clean?

Probably unlikely but could the HE be lime scaled on the water side obviously.

Tony

 

[martineire]

Nozzle is a .75 80S it is the same nozzle that was in it before i touched it but i renewed it obviously. The heat exchanger is clean no soot or sulpher build up. O and how the hell can i find out if the heat exchanger is limescaled?

 

[martineire]

I went back and ive sorted it out now i actually had the oil pressure set at 9 bar pressure wheres a popular 90, max burner settings for 90,000 BTUs is oil set at 8 bar with a .75 80S nozzle which i had fitted at 9bar pressure when making my adjustments. So the burner was overfiring for 26.4kw boiler . But can anyone tell me if i was to leave the burner input setting as they were would this be potientally dangerous or would it just of being a case of a wast of heat out of the flue can anyone tell me???

 

[AlanE]

Bottom baffle would probably melt! If the flue temp was 50% up then the bottom compartment would be even more probably.

 

[martineire]

Really a standard efficency boiler flue gas temp should be around 210 degrees and by just increasing the flue gas temp to 300 would melt the bottom baffle.