506843-01
Page 34 of 39
Issue 1132
9. Remove screws from both sides, top and bottom of
vestibule panel.
10. Remove heat exchanger. It may be necessary to spread
cabinet side to allow more room. If so, remove five
screws from the left side or right side of cabinet. See
Figure 31.
11. Backwash using steam. Begin from the burner opening
on each clam. Steam must not exceed 275° F.
12. To clean burners, run a vacuum cleaner with a soft brush
attachment over the face of burners. Visually inspect
inside the burners and crossovers for any blockage
caused by foreign matter. Remove any blockage. Figure
29 shows burner detail.
13. To clean the combustion air inducer visually inspect and
using a wire brush clean where necessary. Use
compressed air to clean off debris and any rust.
14. Reinstall heat exchanger in vestibule. (Replace the five
screws in the cabinet from step 10 if removed).
15.
NOx units only
- Replace NOx inserts.
16. Reinstall collector box and combustion air assembly.
Reinstall all screws to the collector box and combustion
air inducer. Failure to replace all screws may cause
leaks. Inspect gaskets for any damage and replace if
necessary.
17. Reinstall burner box, manifold assembly and burner box
cover.
NOx INSERTS
Figure 30
18. Reconnect all wires.
19. Reconnect top cap and vent pipe to combustion air
inducer outlet.
20. Reconnect gas supply piping.
21. Turn on power and gas supply to unit.
22. Set thermostat and check for proper operation.
23. Check all piping connections, factory and field, for gas
leaks. Use a leak detecting solution or other preferred
means.
24. If a leak is detected, shut gas and electricity off and
repair leak.
25. Repeat steps 24 and 26 until no leaks are detected.
26. Replace access panel.
Some soaps used for leak detection are corrosive to
certain metals. Carefully rinse piping thoroughly after
leak test has been completed. Do not use matches,
candles, flame or other sources of ignition to check for
gas leaks.
CAUTION
Remove 5 Screws If Necessary
(either side of cabinet)
Figure 31
