4 - Removethecollectorboxlocatedbehindthecombus- tionairinducerBecarefulwiththecollectorboxgas.- ket.Ifthegasketisdamaged,it mustbereplacedto preventleakage,
5 - Labelthewiresfromgasvalveandrolloutswitches, thendisconnectthem.
6 - DisconnectgassupplypipingRemovefourscrewsse.- curingtheburnermanifoldassemblytothevestibule panelandremovetheassemblyfromtheunit,
NOx INSERTS (X models only)
/
FIGURE 31
7 - NOx units only- Remove the three screws that attach the NOx insert to the corbel at the entrance to each
heat exchanger section, Carefully remove the NOx in- sert from each section, See figure 31.
8 - Insert the brush end of cable snake into the top of one of the heat exchanger openings, Do not force the cable into the heat exchanger. Insert the cable and operate the drill on slow speed. Move the cable in and out of the heat exchanger section three or four times or until sufficient cleaning is accomplished. Reverse drill and slowly work the cable out of opening,
9- Repeat procedure for each heat exchanger section.
10- After each of the top heat exchanger sections has been cleaned, insert the brush end of the cable snake into the bottom openings of each of the heat exchanger sections and clean as described in step 8,
11- Remove the cable from the heat exchanger. Use a vac- uum cleaner to remove debris knocked loose during cleaning.
12- Attach the exhaust end (positive pressure) of the vacu- um cleaner to the top of the heat exchanger section, Any loose debris will be forced to the bottom of the heat exchanger section, Vacuum debris from bottom open- ings.
13- Replace collector box and combustion air inducer. Check gaskets for damage. Damaged gaskets must be replaced to avoid heat exchanger leaks. Replace all screws to the collector box and combustion air inducer. Failure to replace all screws may cause leaks,
14- To clean the burner, run a vacuum cleaner with a soft brush attachment over the face of burners. Visually in- spect inside the burners and crossovers for any blockage caused by foreign matter. Remove any blockage,
15- NOx Units - Reattach the NOx inserts to the corbels at the entrance to each heat exchanger opening, See fig- ure 31,
16- Replace burner/manifold assembly onto the vestibule panel,
17- Reconnect wires to pressure switch,
18- Reconnect vent pipe to combustion air inducer outlet, 19- Reconnect gas supply piping,
20- Turn on power and gas supply to unit,
21- Set thermostat and check for proper operation,
22- Check all piping connections, factory and field, for gas leaks. Use a leak detecting solution or other preferred means,
Ak CAUTION
23- Ira leak is detected, shut gas and electricity offand repair leak,
24- Repeat steps 23 and 24 until no leaks are detected. 25- Replace front access panel.
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