Proper Burner Flame. Cozy Hi-Efficient Direct Vent

BURNER

PROPER BURNER FLAME

The burner flame may be observed by raising the sight glass cover. A proper flame will have a dark blue inner mantle, with a lighter blue outer mantle that extends from the burner into the heat exchanger tube, (see Figure 11).

There is no primary air adjustment on the burner, and proper flame is assured since the correct manifold pressure and orificing have been done at the factory.

FIG. 11

Primary Flame

Burner

Heat Exchanger Tube

Secondary Flame

TO REMOVE MAIN BURNER

FOR INSPECTION AND CLEANING

1. Turn off all electrical supply to heater.

2. Turn off gas supply.

3. Remove front panel.

4. Unplug wire to direct spark ignitor and sensor.

See Figure 12.

5. Disconnect vacuum hose from burner box.

6. Remove screws holding burner box top to burner box.

See Figure 12.

7. Remove burner plate and burner box top. Take care not to contact, or strain ignitor in any way as it is extremely fragile.

See Figure 12.

8. Remove 2 nuts holding burner bracket.

See Figure 12.

9. Slide burners toward heat exchanger and lift up from rear and back. See Figure 12.

10. Clean or replace as needed.

11. Reinstall by reversing Steps 9–1.

NOTE: The furnace and all components must be inspected at least annually by a qualified service

technician. This should include the burner, heat exchanger, and vent system. Be sure that the flow of combustion and ventilation air are not obstructed and that all hoses are undamaged, and all clamps are securely tightented.

FIG. 12

Maxitrol

Gas

Valve

Burner

Box Top

BURNER ORIFICE

This appliance equipped only for altitudes 0 - 2,000 ft.

Appliance input ratings are based on sea level operation and need not be changed for operation up to 2,000 feet

(609.9 m) elevation. For operation at elevations above

2,000 feet (609.9 m).

The BTU input must be reduced 4% per 1,000 ft. Orifice change must be completed by a qualified installer or service technician. See the following orifice chart for the proper orifice drill size for a specific elevation.

Direct

Spark Ignitor

Burner

Burner

Bracket

Manifold

NATURAL GAS - (SPECIFIC ELEVATIONS)

Model No.

HEDV253A

HEDV403A

0 to

2,000’

51

45

2,000 -

4,000’

52

47

4,000 -

6,000’

52

48

6,000 -

8,000’

53

49

8,000 -

10,000’

54

50

1017952-A Page 12

PROPANE GAS - (SPECIFIC ELEVATIONS)

Model No.

HEDV254A

HEDV404A

0 to

2,000’

58

55

2,000 -

4,000’

60

55

4,000 -

6,000’

62

56

6,000 -

8,000’

63

56

8,000 -

10,000’

64

57

WIRING

!

WARNING: THIS IS A GAS-FIRED APPLIANCE. KEEP THE AREA CLEAR OF GASOLINE AND OTHER

FLAMMABLE VAPORS AND LIQUIDS. ALL COMBUSTIBLE MATERIAL MUST BE KEPT CLEAR OF THIS

AREA TO AVOID FIRE OR EXPLOSION.

This appliance is equipped with a three prong power cord with grounding plug. For your protection against shock hazard, this appliance should be plugged directly into a properly grounded three-prong receptacle. Do not cut or remove the grounding prong from this plug.

NOTE: If any of the original wire supplied with this appliance has to be replaced, it must be replaced with type 105ºC wire or its equivalent.

CAUTION: Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation.

Verify proper operation after servicing.

FIG. 13

Black

Purple Red

Thermostat

White

HEDV25-A

HEDV40-A

PICTORIAL

Red

Orange

Black

Yellow

GROUND

24V

Circuit Board

R G W C

CMB Blower

L1

ACC

ACB COOL

Transformer

Black

Green

Black

Black

Draft Inducer

HEDV25-A

HEDV40-A

LADDER

Gas Valve

Pressure Switch

Limit Switch

Thermostat 24 VAC

Circuit Board

115 VAC

Draft Inducer

Circulating Blower

WIRING DIAGRAM | HEDV253A, HEDV254A, HEDV403A & HEDV404A

Page 13 1017952-A