How To Check Gas Combustion
The combustion testing and adjustments must be performed by a qualified installer, service agency or the gas
supplier. All combustion analyzer must be performed with calibrated equipment to ensure proper reading and
accuracy.
If the combustion levels are not within the range given in Table 1 for the firing rate, shut the unit and contact
Eternal Engineering support team. Failure to comply with this requirement could result in severe personal injury,
death or substantial property damage.
After setting, the CO level should not exceed maximum 200 ppm for both Natural and Propane gas.
WARNING
!
!
Recommended Combustion Levels
Setting values O
2
/ CO
2
Model
Gas type
Natural gas
Propane gas
O
2
CO
2
O
2
CO
2
GU100
3.0 - 6.5%
8.0 - 10.0%
3.5 - 6.9%
9.0 - 11.0%
(Table 1)
42
EC Adapter Cap
Analyzer Probe
Gas Analyzer
Gas / Air Ratio Valve
Inlet pressure port
Adjustment screw A (Tool: T40 trox bit)
Manifold pressure port
NOTICE
!
Using a combustion analyzer is required for checking
and tuning the gas valve.
!
Please loosen the 1/8" NPT screw and check
the manifold pressure by using a manometer
with 0.01" W.C. resolution.
Please check the inlet pressure to ensure
the incoming gas pressure is within unit's
required specification.
Min and Max inlet and manifold pressures are
indicated on the Eternal OM and Rating label.
