AERCO KC Standard to Low NOx Convertion Instructions User Manual
Page 8
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CAUTION
USE CARE WHEN REMOVING THE AIR/FUEL VALVE TO AVOID
DAMAGING OR LOSING THE FLANGE O-RING.
21.
Completely remove the Air/Fuel Valve from the unit. This assembly will be modified in
Section 3.
22.
Remove the Exhaust Manifold insulation (Figure 4) by removing the three 1/4-20 screws and
fender washers securing it in place.
NOTE
Current KC1000 units are equipped with Siemens Safety Shutoff Valves
(SSOVs). However, some earlier units may be equipped with Honeywell
SSOVs. The mounting location of the Low Pressure Gas Switch will differ
slightly, depending on the SSOV installed. Refer to Figure 6 (Siemens) or
Figure 7 (Honeywell) for the appropriate SSOV installed.
23.
Next, refer to Figure 6 (Siemens SSOV) or Figure 7 (Honeywell SSOV) to locate the Low
Pressure Gas Switch on the right side of the unit. Disconnect the two wire leads from the
switch.
24.
For Siemens SSOVs, the Low Pressure gas Switch is installed in the upstream SSOV port
using an NPT reducer. For Honeywell SSOVs, the Switch is installed directly in the gas supply
inlet pipe. Temporarily remove the Low Pressure Gas Switch as follows:
(a) For Siemens SSOVs, remove the switch (with NPT reducer attached) from the upstream
SSOV port using a 5/8” wrench.
(b) For Honeywell SSOVs, remove the switch from the tapped hole in the gas supply inlet
pipe using a 1/2” wrench.
The Low Pressure Gas Switch will be reinstalled in Section 4.