Greenheck Fan PVF Start-UpProcedure, Sequence of Operation, Recovery from Lockout, Heat Mode

Start-Up Procedure

1.Turn off power to the unit at the disconnect switch. Close all manual gas valves.

2.Check that all gas and electrical connections are weatherized.

3.Make sure that the combustion air inlet and the combustion blower discharge are free from obstructions.

4.Inspect the unit to make sure that no damage has occurred during installation.

5.With the furnace control center access panel removed, connect a “U” tube manometer to the manifold pressure test port as shown in Figure 2. This will be used for checking the manifold gas pressure.

6.Set the thermostat or discharge temperature controls to lowest setting.

Sequence of Operation

Power-up/Standby

After power is supplied to the unit:

1.The ignition control will reset and perform a self- check routine.

2.The diagnostic LED will flash for up to four seconds.

3.The ignition control will begin scanning the thermostats.

Heat Mode

When the thermostat or discharge temperature controls call for heat:

1.The ignition control will check that the pressure switch for the combustion blower is open.

2.The combustion blower will be energized and the 15-second pre-purge begins.

3.The gas valve is energized and the igniter will spark for up to 10 seconds.

Natural Gas - If a flame is not sensed during the trial for ignition, two additional trials will be attempted before going into lockout for one hour.

LP Gas - If a flame is not sensed during the trial for ignition, the control will go into lockout for one hour.

4.When a flame is sensed, sparking stops immediately. The gas valve and combustion blower remain energized.

7.Open all manual gas valves including the combination gas valve and turn power on.

8.Call for heat with the thermostat or discharge temperature controls and allow the burner to light. Greenheck duct furnaces are equipped with an automatic spark ignition system which automatically lights the burner. DO NOT attempt to light the burners manually.

9.After the burner is lit, check to make sure that the supply blower is operating.

10.Verify that the gas controls sequence properly (see Sequence of Operation below).

11.Check the manifold gas pressure (see Burner Adjustments on pages 5 and 6).

5a. Two-stage control: The burner will light at 100% fire and remain there for 10 seconds. The thermostat will then operate the burners at high or low fire, depending on the demand for heat.

5b. Electronic Modulation - The burner will light at

100% fire and remain there for 10 seconds. The main burner gas valve will then modulate from 100% down to 50% as needed. If the burner remains on low fire for an extended period of time, the burner will shut off and re-light as necessary.

6.The ignition control constantly monitors the thermostat, pressure switch, and burner flame to assure proper operation.

7.When the thermostat or discharge temperature controls are satisfied, the main valve is de- energized and the combustion blower shuts off following a 30-second post-purge period.

Recovery from Lockout

The ignition control will automatically reset after 1 hour if the thermostat is still calling for heat. Prior to 1 hour, a manual reset (cycle power to unit) is required. The thermostat may be reset or the power interrupted for a period of 5 seconds. See page 7 for Ignition Control Diagnostics.

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