Trane GHND-SVX01A-EN T. Too much heat., U. Cold air is delivered on start up., V. Cold air is delivered during heater operation.

GHND-SVX01A-EN • High Efficiency Propeller Fan Gas Unit Heater 43
Trouble Shooting
3. Thermostat malfunction.
4. Heater cycling on limit control.
CORRECTIVE ACTION
• Refer to “Operation”.
• This is especially true when the heated space is enlarged. Have the heat loss
calculated and compare to the heater output (80% of input). Your gas supplier or
installer can furnish this information. If heater is under sized, add additional
heaters.
• Replace thermostat.
• There should be NO ducts attached to the front of this heater. Check air movement
through heat exchanger. Check voltage to fan motor. Clean fan blade and heat
exchanger and oil fan motor.
T. Too much heat.
POSSIBLE CAUSE(S)
1. Thermostat malfunction.
2. Heater runs continuously.
CORRECTIVE ACTION
• Replace thermostat.
• Check wiring per diagrams; Check operation at valve. Look for short (such as staples
piercing thermostat wiring), and correct; Replace gas valve; Refer to “Operation”.
U. Cold air is delivered on start up.
POSSIBLE CAUSE(S)
1. Fan switch heater element improperly wired.
CORRECTIVE ACTION
• Be sure fan switch heater terminals are connected per diagrams.
V. Cold air is delivered during heater operation.
POSSIBLE CAUSE(S)
1. Incorrect manifold pressure or input.
2. Voltage to unit too high.
3. Air through put too high.
CORRECTIVE ACTION
• Refer to “Operation”.
• Check motor voltage with fan running. Should be 115 volts AC.
• Refer to “Operation”.