P-K SONIC
TM
Gas Fired Boiler
T
T
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Technical Service 1.877.728.5351
echnical Service 1.877.728.5351
echnical Service 1.877.728.5351
echnical Service 1.877.728.5351
Appendix B – Boiler Altitude Derate Schedule
For installations over 2000 ft. elevations, a derate schedule is applied. The boiler input rating must be
reduced by
4% per 1000 ft. which is illustrated in the graph below.
Derate procedure is as follows:
With the boiler at high fire, adjust the gas valves to get 5% O2 in the flue gas.
Refer
to
Section 3.12.2
Combustion Setup and Adjustment
.
If this cannot be achieved, perform the following steps:
•
If the O2% is too high, then the inlet gas pressure should be adjusted to the minimum pressure
allowed, typically 5”
W.C.
The gas valve should be adjusted to obtain approximately 5% O2. If the
O2% is still too high, the fan speed may be lowered. This procedure should only be performed by
factory trained personnel.
•
If the O2% is too low, then the gas valve settings should be reduced. This procedure is also described
in Bulletin 06-08.
