14
13. Perform the following combustion analysis. All adjustments below must be made with the following instruments: draft
gauge, O
2
or CO
2
analyzer and CO tester.
A. Adjust the primary air damper to provide about 25% excess combustion air. Confirm this by checking the flue gas
for its FREE OXYGEN (O
2
) or CARBON DIOXIDE (CO
2
) PERCENTAGES with a test instrument. Free oxygen
should be about 4.5%, or carbon dioxide should be about 9.5% for natural gas, 12.1% for propane gas.
B. CARBON MONOXIDE (CO)– Should be checked for its presence in the flue gas. This percentage
should not exceed .04% (or 400 PPM air free).
If an O
2
analyzer is used:
CO
AIRFREE
= x CO
PPM
If a CO
2
analyzer is used:
For Natural Gas: CO
AIRFREE
= x CO
PPM
For Propane Gas: CO
AIRFREE
= x CO
PPM
C. NOTE: The EHG was designed to fire into slightly positive, balanced, or slightly negative combustion chambers. For
optimal performance, check overfire draft and adjust to NEGATIVE -.01 (-2.5Pa) to -.02 (-5.0 Pa) inches w.c. during
burner operation.
D. The flue gas temperature should be between 325°F (163 °C) and 550°F (288 °C) for gas burners. Higher flue gas
temperatures indicate overfiring or excessive draft through the appliance. Lower flue gas temperatures may cause
excessive condensation and indicate underfiring. Consult your local utility or the appliance manufacturer for acceptable
flue gas temperatures.
CAUTION: IF THE BURNER Btu/hr (kW) INPUT IS CHANGED, THE AIR SHUTTER MUST BE ADJUSTED. REPEAT
STEP 13
14. Adjust the High & Low gas pressure switches according to actual firing conditions. The High gas pressure switch
should be set at approximately 4”w.c. and the Low gas pressure switch should be set at approximately 2”w.c. for close
burner control. Nuisance lockouts will occur if the switch settings are too close to the gas manifold setting, and
fluctuations in gas pressures occur. Reattach switch covers.
15. Record the installation data, the combustion readings, etc., and affix to this manual, or the burner and/or appliance.
Space has been provided at the back of this manual for start-up notes, dealer’s name, address, telephone number, as
well as the date of installation.
SUGGESTION: All new installations should be re-inspected for proper combustion and burner operation after one or two
weeks of normal operation.
For subsequent normal starting and shut off procedure, refer to the “Consumer Instructions” in the back of this manual or
the instruction plate attached to the burner.
TO RESTART THE BURNER AFTER A FLAME FAILURE, remove power from the burner for 1 minute to reset the
primary controller. Push the manual reset on the Low Gas pressure switch. The burner should relight after power is
restored and the unit has a call for heat. If problems persist, refer to the troubleshooting section of this manual.
To stop the burner in the event of an emergency, remove power from the main electrical disconnect, shut off any manual
gas ball valve, or turn the burner on-off switch to the off position.
20.9
(20.9 – %O
2
)
11.7
% CO
2
13.8
% CO
2
To Next Page
Loading...
