26
EX38DT Installation and Operation Manual
Instructions:
Natural Gas
Short Vent Lengths:
0 - 7 ft (2 m) + 1 elbow (A1 - A4)
Long Vent lengths:
7 ft (2 m) +1 elbow - 13 ft (4 m) + 3 elbows (A5 - A8)
Propane Gas
Short Vent Lengths:
0 - 7 ft (2 m) + 1 elbow (L1 - L4)
Long Vent lengths:
7 ft (2 m) +1 elbow - 13 ft (4 m) + 3 elbows (L5 - L8)
Code
A1 / A5
A2 / A6
A3 / A7
A4 / A8
L1 / L5
L2 / L6
L3 / L7
L4 / L8
Altitude
0-2,000 ft
0-610 m
2,001-5,400 ft
611-1,646 m
5,401-7,800 ft
1,647-2,377 m
7,801-10,200 ft
2,378-3,109 m
0-2,000 ft
0-610 m
2,001-5,400 ft
611-1,646 m
5,401-7,800 ft
1,647-2,377 m
7,801-10,200 ft
2,378-3,109 m
Manifold test
pressure - W.C.
Low
1.69 in.
(43 mm)
1.59 in.
(40 mm)
1.49 in.
(38 mm)
1.43 in.
(36 mm)
3.21 in.
(82 mm)
3.01 in.
(76 mm)
2.85 in.
(72 mm)
2.73 in.
(69 mm)
Manifold test
pressure - W.C.
High
3.8 in.
(96 mm)
3.0 in.
(76 mm)
2.7 in.
(68 mm)
2.5 in.
(62 mm)
6.4 in.
(162 mm)
5.6 in.
(143 mm)
5.1 in.
(129 mm)
4.6 in.
(116 mm)
1. Turn off the gas and the power
supply.
2. Remove the 3 screws that hold the
front panel. Lift the panel straight up
and then remove.
3. Remove test port screws (1/8 NPT
tap) with 3/16 Allen wrench located
at gas valve and burner cover.
Install two 1/8 in. barb fittings (field-
supplied). Attach dual port
manometer to the test ports as
shown. Ensure that the manometer
is properly calibrated.
4. Turn on the gas and power supply
to the furnace.
5. Ensure “Set Back” feature has been
deactivated. (“Set Back” feature is
active by default.)
6. With the unit in the Off position,
press the Test Switch at the bottom,
right of PC board until it beeps.
7. Select the correct code for gas type,
altitude, and vent length on the LED
display using
▲
and
▼
buttons.
Refer to the table below.
Table 8: Gas Pressure
Figure 33
Negative
Port
Positive
Port
PCB Test
Switch
Summary of Contents for EX38DT
Page 41: ...EX38DT Installation and Operation Manual 41 8 Parts Cut Away Diagram Figure 58 ...
Page 42: ...42 EX38DT Installation and Operation Manual Exploded View of Service Parts Figure 59 ...
Page 43: ...EX38DT Installation and Operation Manual 43 Exploded View of Service Parts Figure 60 ...
Page 44: ...44 EX38DT Installation and Operation Manual Exploded View of Service Parts Figure 61 ...
Page 45: ...EX38DT Installation and Operation Manual 45 Exploded View of Service Parts Figure 62 ...
Page 46: ...46 EX38DT Installation and Operation Manual Exploded View of Service Parts Figure 63 ...