Sequence of Operations. Cozy Hi-Efficient Direct Vent

HEDV SEQUENCE OF OPERATIONS

Heater in

Stand-by

Thermostat

Calls for Heat

Power on to Draft

Inducer

Pressure

Switch Closes

Inducer Proved

YES

NO

Inducer Continues to Run

Spark

Ignition

Energized

Pressure Switch Closes

Proving Inducer

NO

YES

One Hour Lock Out

4 Sec.

Gas Valve

Opens Gas Flow to Burner

Burner

Flame

Proved

YES

NO

90 Sec.

Blower

On

15 Second Inter Purge

3 Attempts for Ignition

NO

YES

Heat

Cycle

Thermostat

Satisfied

Gas Valve

Closes Gas Flow to Burners Off

180 Sec.

30 Sec.

Draft

Inducer

Blower

Off

Heater in Standby

STEP #:

1) Thermostat calls for heat.

2) Draft Inducer turns on.

3) Pressure switch closes.

4) Spark ignition begins.

5) Gas flow to burner.

6) Burner ignition proven.

7) Circulating Blower on.

8) Heater burns through heating cycle.

9) Thermostat satisfied.

10) Gas flow off to burner.

11) Draft inducer off.

12) Circulating Blowers off.

13) Heater in stand-by.

NOTE: If there is a malfunction during Steps 3, 5 or 6 the operation sequence will stop at that point. For Steps 5 or 6, if the malfunction still occurs after two additional attempts, the control will lock out for one hour. For purpose of testing, the one hour lockout can be overridden by resetting the thermostat or interrupting the electrical power.

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