Furnace condensate is mildly acidic, typically in the pH range of
3.2 to 4.5. Due to corrosive nature of this condensate, a condensate
pH neutralizing filter may be desired. Check with local authorities
to determine if a pH neutralizer is required.
APPLICATION
The furnace, A/C, and humidifier drains may be combined and
drained together. The A/C drain must have an external, field-
supplied trap prior to the furnace drain connection. All drain
connections (furnace, A/C, or humidifier) must be terminated into
an open or vented drain as close to the respective equipment as
possible to prevent siphoning of the equipment’s drain.
See Fig. 44 for example of possible field drain attachment using
1/2-in. CPVC or PVC tee for vent and A/C or humidifier drain
connection.
Outdoor draining of the furnace is permissible if allowed by local
codes. Caution should be taken when freezing ambient may freeze
drain pipe and prohibit draining.
PERSONAL INJURY HAZARD
Caution should be taken to prevent draining where slippery
conditions could cause personal injuries.
Excessive condensate draining may cause saturated soil
conditions which could result in damage to plants.
CONDENSATE DRAIN PROTECTION
Freezing condensate left in condensate trap and drain line may
cause cracks, and possible water damage may occur. If freeze
protection is required, use condensate freeze protection accessory
or equivalent 3 to 6 watt per ft at 120–v and 40°F self-regulating,
shielded, and waterproof heat tape. See Installation Instructions
supplied with accessory or heat tape manufacturer’s recommenda-
tions.
1. Fold heat tape in half and wrap on itself 3 times.
2. Locate heat tape between sides of condensate trap back. (See
Fig. 45.)
3. Use wire ties to secure heat tape in place. Wire ties can be
positioned in notches of condensate trap sides. (See Fig. 45.)
4. Wrap field drain pipe with remaining heat tape, approximately
1 wrap per ft.
5. When using field-supplied heat tape, follow heat tape manu-
facturer’s instructions for all other installation guidelines.
START-UP, ADJUSTMENTS, AND SAFETY CHECK
Step 1—General
1. Furnace must have a 115-v power supply properly connected
and grounded.
NOTE:
Proper polarity and proper grounding must be maintained
for 115-v wiring. If polarity is incorrect, control LED status
indicator will flash rapidly and furnace will not operate.
2. Thermostat wire connections at terminals R, W, G, and Y/Y2
must be made at 24-v terminal block on furnace control.
3. Natural gas service pressure must not exceed 0.5 psig (14-in.
wc), and be no less than 0.16 psig (4.5-in. wc).
4. Blower access panel must be in place to complete 115-v
electrical circuit to furnace.
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent unit
operation.
These furnaces are equipped with a manual reset limit switch
in burner box. This switch will open and shut off power to gas
valve if an overheat condition (flame rollout) occurs in burner
enclosure. Correct inadequate combustion-air supply or im-
proper venting condition and reset switch. DO NOT jumper
this switch.
Before operating furnace, check flame roll-out manual reset switch
for continuity. If necessary, press button to reset switch.
Fig. 44—Example of Field Drain Attachment
A94054
OPEN STAND
PIPE FOR
A/C OR
HUMIDIFIER
DRAIN
TEE
TO OPEN
DRAIN
Fig. 45—Condensate Trap Heat Tape
A93036
CONDENSATE TRAP
WIRE TIE(S)
HEAT TAPE
(3 WRAPS MINIMUM)
42