AERCO KC1000 Low NOx Boiler July 2011 - Manual (Page 109)

APPENDIX J
J - 1
KC1000 LOW NOx DUAL-FUEL
SWITCH-OVER INSTRUCTIONS
The KC1000 Low NOx Boiler is shipped from the factory configured for either natural gas or
propane operation, as specified on the Sales Order. However, if required, the unit’s operating
configuration can be easily switched from natural gas to propane (or vice-versa) by performing a
simple change to the spring contained in the unit’s differential regulator.
The extra spring required to switch from natural gas to propane, or from propane to natural gas
is included with the unit accessories (see Chapter 2, para. 2.2). Units configured for natural gas
operation include a zinc-plated regulator spring, part no. 124803. Units configured for propane
operation include a brown painted spring, part no. 122548.
The following instructions provide the steps necessary to convert the unit from Natural Gas to
Propane operation. Proceed as follows:
1. Shut down the unit and close the external gas supply valve.
2. Remove the sheet metal covers and locate the differential regulator on the left side of
the unit.
3. Refer to Figure 1 and remove the cap on the differential regulator.
4. Using a flat-blade screwdriver, remove the adjustment screw by turning it counter-
clockwise. Remove the installed zinc-plated regulator spring (124803) used for Natural
Gas operation. DO NOT DISCARD THE REMOVED SPRING.
5. Install the brown painted spring (122548) required for Propane operation.
6. Replace the regulator adjustment screw. Rotate the screw clockwise to a depth of 1-1/2
inches from the top of the regulator housing.
7. Upon completion of the spring change, perform the combustion calibration procedures in
Section 4 of this Instruction Manual.
REGULATOR CAP
CAP GASKET
ADJUSTMENT
SCREW
SPRING
(PARTIALLY
REMOVED)
DIFFERENTIAL GAS
PRESSURE REGULATOR
FIGURE 1. REGULATOR SPRING REPLACEMENT