P-K SONIC
®
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: June 2, 2017
Released: June 2, 2017
HARSCO Industrial, Patterson-Kelley 2017
All Rights Reserved.
1004905978 P-K SONIC NURO Installation and
Owners Manual (Rev F Jun-2017).docx
Page 98
Appendix B
– Boiler Altitude Derate Schedule
For installations over 2,000 ft. elevations, a derate schedule is applied. The boiler input rating must be
reduced by
4% per 1,000 ft. which is illustrated in the graph below.
Although the appliance’s capacity is reduced due to the lower air density, the combustion tuning should
follow the standard combustion guidelines of
. Tune the combustion for the same O
2
and CO
2
levels as discussed in
