The Importance of Combustion Analysis
The importance of undertaking combustion analysis upon gas & oil fired heating and cooking appliances cannot be over-emphasised.
Failure to do so, can have catastrophic consequences!
One example that serves to reinforce the importance of undertaking combustion performance analysis, was encountered recently.
An oil boiler had been serviced for a number of years by another engineer, clearly analysis of the products of combustion had not been carried out during any service visit.
This oil boiler was just over 6 years old!
Following the service, combustion analysis was undertaken and the readings obtained on our Analyser are shown below.
Apologies for the slightly blurred picture.
C02 - was 8.7%
CO - was 856ppm – Yes that was; 856ppm
CO/CO2 Ratio - was 0.0099
O2 - was 9.2%
Excess air - was 78.9%
Absolutely atrocious!
The balanced flue outlet was also very close to the entrance doorway into the rear of the property.
Further investigation revealed the boiler data badge was incorrect, stating an EH pattern nozzle when it should have been an ES.
The Data Badge entry shown below.
Nozzle fitted during all previous service visits, according to the boiler Data.
Appliance data we obtained from technical manual is shown below.
Nozzle fitted on our visit to this boiler is shown below.
Combustion analysis undertaken following change of nozzle spray pattern, shown below.
No adjustments were made to pump pressure nor air shutter setting, prior to the analysis.
Now the readings were as follows:-
CO2 - up from 8.7% to 11.8%
CO - down from 856ppm to 7ppm – yes that is 7ppm
CO/CO2 ratio - down from 0.0099 to unrecorded.
O2 - down from 9.2% to 5%
Excess air - down from 78.9% to 31%
All that remained, was to carry out a minor reduction in the burner air setting following the analysis and to observe the improved readings.
Comments