h. Turn off all electrical power to the system.
i. Remove the manometer and flexible tubing. Re- move the barbed fitting and replace the plug or tighten the pressure test screw.
j. Turn on electrical power to the system and ener- gize valve.
k. Using a leak detection solution or soap suds, check for leaks at plug or pressure boss screw.
▲! WARNING
Replace and/ or tighten all plugs removed or loosened when adjusting gas pressure. Leak check the fittings before placing the furnace into regular service.
Failure to follow this warning could result in fire, ex- plosion, or property damage.
Installer’s Guide
Table 14 lists the main burner orifices used with the furnace. If a change of orifices is required to correct the furnace input rating. Refer to Table 17.
TABLE 15
FINAL MANIFOLD PRESSURE SETTINGS
FUEL | PRESSURE |
NATURAL GAS | 3.5" W.C. |
|
|
LP GAS | 11.0" W.C. |
|
|
Y
NOTE:
The manifold pressure must be referenced to the burner box. The burner box pressure tap equalizes the gas valve pressure regulator. Manifold pressure is checked by installing a tee (field supplied) in the tub- ing, between the tee coming from the burner box tube and the gas valve, in addition to the regular gas valve pressure tap on the outlet side of the gas valve. See Figure 53.
▲! CAUTION
Replace manifold pressure tap threaded plug and leak check after checking/ adjusting manifold gas pressure.
33 |
