Reznor VR Unit Installation Manual User Manual

Page 44

Form I-VR, P/N 205202 R13, Page 43

PROBLEM

PROBABLE CAUSE

REMEDY

Burner cycles

on and off

1. Gas pressure too high or too low.

1. See Gas Supply Pressure Table, Paragraph 6.3.

2. DSI control board not grounded.

2. Make certain DSI control board is grounded to furnace chassis.

3. Faulty DSI control board.

3. If 24 volt is available to the DSI control board and all other causes have

been eliminated, replace board.

4. Combustion air proving switch

not closing.

a) Make sure unit is properly vented.

b) Remove obstructions from vent.

c) Replace faulty tubing to pressure switch.

5. Faulty combustion air proving switch.

5. Replace combustion air proving switch.

6. Spark electrode assembly grounded.

6. Be certain spark electrode assembly lead is not grounded or insulation

or ceramic is not cracked. Replace as required.

7. Cracked ceramic at spark electrode assembly. 7. Replace spark electrode assembly.

No heat (Heater

Operating)

1. Incorrect valve outlet pressure.

1. Check valve outlet pressure. See Rating plate for valve outlet pressure.

2. Improper thermostat location or adjustment.

2. See thermostat manufacturer’s instructions.

Blower motor

will not run

1. Circuit open.

1. Check wiring and connections.

2. Defective DSI control board.

2. Replace board.

3. Defective motor.

3. Replace motor.

Blower motor

turns on and

off while burner

is operating

1. Motor overload device cycling on and off.

1. Check motor load against motor rating plate. Replace motor if needed.

Blower motor

cuts out on

overload

1. Low or high voltage supply.

1. Correct electric supply.

2. Defective motor.

2. Replace motor.

3. Poor air flow.

3. Clean motor and blower.

4. Defective bearing.

4. Replace motor.

Trial for

Ignition

Call for Heat

Is there a

spark across gap at

ignitor?

Does gas

ignite?

Is the

spark ignitor

corroded?

Clean spark

ignitor.

Is the spark

ignitor in flame

correctly?

Replace spark

ignitor.

Repositon

spark ignitor.

Is gas flowing?

Is the ignitor

position correct in the

gas flow?

Check gas pressure

and supply voltage. If

either are low, correct

and repeat startup.

Reposition spark

ignitor.

Is there

24VAC at the gas

valve?

Is there 24VAC

from gas valve output on

DSI control board to

chassis?

Check wiring

and connections

to gas valve.

Replace DSI

control board.

Replace gas

valve.

Is there spark

voltage at DSI control

board?

Check high

voltage wire

continuity.

Is there 24V

to "W" to power

control?

Replace DSI

control board.

Check wiring

and/or 24VAC

transformer output.

YES

FIGURE 44 - Ignition Troubleshooting Guide

(Assumes pressure switch is actuated.)