12− | If the appliance will not operate, follow the instructions | |
| urning Off Gas to Unit" and call your service techni- | |
| cian or gas supplier. |
|
Turning Off Gas to Unit |
| |
1 − | Set the thermostat to the lowest setting. | |
2 − | Turn off all electrical power to the unit if service is to be | |
| performed. |
|
3 − | Remove the upper access panel. | |
4 − | White Rodgers 36E Gas Valve − Move gas valve | |
| switch to OFF. |
|
| Honeywell VR8205 Gas Valve − Move switch on gas | |
| valve clockwise | to OFF. Do not force. |
5 − | Replace the upper access panel. | |
Gas Pressure Adjustment
Gas Flow (Approximate)
1 − Operate unit at least 15 minutes before checking gas flow. Determine the time in seconds for one revolu- tions of gas through the meter. A portable LP gas me- ter (17Y44) is available for LP applications.
2 − Compare the number of seconds and the gas meter size in table 12 to determine the gas flow rate. Multiply the gas flow rate by the heating value to determine the unit input rate. If manifold pressure is correct and the unit input rate is incorrect, check gas orifices for proper size and restriction.
3 − Remove temporary gas meter if installed.
NOTE − To obtain accurate reading, shut off all other gas appliances connected to meter.
Supply Pressure Measurement
A threaded plug on the inlet side of the gas valve provides access to the supply pressure tap. Remove the threaded plug, install a field−provided barbed fitting and connect a manometer to measure supply pressure. Replace the threaded plug after measurements have been taken.
Manifold Pressure Measurement
To correctly measure manifold pressure, the differential pressure between the positive gas manifold and the nega- tive burner box must be considered. Use pressure test adapter kit (available as Lennox part 10L34) to assist in measurement.
1 − Remove the threaded plug from the outlet side of the gas valve and install a field−provided barbed fitting. Connect test gauge
measure manifold pressure.
2 − Tee into the gas valve regulator vent hose and connect test gauge
TABLE 12
Gas Flow Rate (Ft.3/Hr.)
Seconds for 1 | Gas Meter Size | |
Revolution | 1/2 cu ft Dial | 1 cu ft Dial |
|
|
|
10 | 180 | 360 |
|
|
|
12 | 150 | 300 |
|
|
|
14 | 129 | 257 |
|
|
|
16 | 113 | 225 |
|
|
|
18 | 100 | 200 |
|
|
|
20 | 90 | 180 |
|
|
|
22 | 82 | 164 |
|
|
|
24 | 75 | 150 |
|
|
|
26 | 69 | 138 |
|
|
|
28 | 64 | 129 |
|
|
|
30 | 60 | 120 |
|
|
|
32 | 56 | 113 |
|
|
|
34 | 53 | 106 |
|
|
|
36 | 50 | 100 |
|
|
|
38 | 47 | 95 |
|
|
|
40 | 45 | 90 |
|
|
|
42 | 43 | 86 |
|
|
|
44 | 41 | 82 |
|
|
|
46 | 39 | 78 |
|
|
|
48 | 38 | 75 |
|
|
|
50 | 36 | 72 |
|
|
|
52 | 35 | 69 |
|
|
|
54 | 33 | 67 |
|
|
|
56 | 32 | 64 |
|
|
|
58 | 31 | 62 |
|
|
|
60 | 30 | 60 |
3 − Start unit on low heat (68% rate) and allow 5 minutes for unit to reach steady state.
4 − While waiting for the unit to stabilize, notice the flame. Flame should be stable and should not lift from burner. Natural gas should burn blue.
5 − After allowing unit to stabilize for 5 minutes, record manifold pressure and compare to value given in table 13.
6 − Repeat steps 3, 4 and 5 on high heat.
NOTE − Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to remove barbed fitting and replace threaded plug.
CAUTION
Do not attempt to make adjustments to the gas valve.
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