18-CD29D1-3
33
Installer’s Guide
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 55.
▲
CAUTION
!
Replace manifold pressure tap threaded plug and leak
check after checking/ adjusting manifold gas pressure.
Table 19 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 20.
TABLE 17
FINAL MANIFOLD PRESSURE SETTINGS
MODEL
FUEL
PRESSURE
NATURAL GAS
LP GAS
*UH1B040A9241A
3.5" W.C.
11.0" W.C.
*UH1B060A9361A
3.5" W.C.
11.0" W.C.
*UH1B080A9421A
*UH1C080A9601A
3.5" W.C.
11.0" W.C.
*UH1C100A9481A
*UH1D100A9601A
3.5" W.C.
11.0" W.C.
*UH1D120A9601A
3.3" W.C.
11.0" W.C.
*DH1B040A9241A
3.5" W.C.
11.0" W.C.
*DH1B065A9421A
3.0" W.C.
9.5" W.C.
*DH1C085A9481A
3.5" W.C.
11.0" W.C.
*DH1D110A9601A
4.5" W.C.
11.0" W.C.
5. Adjust gas heat by removing the adjustment
regulator cover screw.
a. To increase outlet pressure, turn the regulator
adjust screw clockwise.
b. To decrease outlet pressure, turn the regulator
adjust screw counterclockwise.
c. Adjust regulator until pressure shown on mano-
meter matches the pressure specified in Table
17.
1. The input of no more than nameplate rating
and no less than 93% of the nameplate rating,
unless the unit is derated for high altitude.
d. Replace and tighten the regulator cover screw
securely.
6. Cycle the valve several times to verify regulator
setting.
a. Repeat steps 5-6 if needed.
7. Turn off all electrical power to the system.
8. Remove the manometer and flexible tubing and
tighten the pressure tap screw.
9. Using a leak detection solution or soap suds, check
for leaks at the pressure outlet boss and pressure
tap test screw.
10. Turn on system power and check operation of the
unit.
u
n
i
t
.
▲
WARNING
!
SAFETY HAZARD
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.
T
Содержание *DH1B040A9241A
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