Sterling GF-250, TF-400, TF-150, TF-300, TF-200, TF-350 Symptoms, Possible Causes, Corrective Action

Table 6 - Tubular Propeller Troubleshooting Guide (continued)

SYMPTOMS	POSSIBLE CAUSE(S)	CORRECTIVE ACTION
I. Burners will not shut off.	1. Thermostat located incorrectly.	1. Relocate thermostat away from outside
		wall or drafts.
	2. Improper thermostat wiring.	2. Check thermostat circuit for open and close
		on terminal strip on heater “R” and “W”.
	3. Shorted circuit.	3. Check thermostat circuit for shorts “staples
		piercing wires”.
	4. Defective sticking gas valve.	4. Check for 24v on gas valve terminals when
		thermostat is not calling.
	5. Excessive gas supply pressure.	5. Refer to “Installation”.
J. Rapid burner cycling.	1. Loose electrical connections at thermostat	1. Tighten all electrical connections.
	or gas valve.
	2. Excessive thermostat heat	2. Adjust heat anticipator setting for longer
	anticipator setting.	cycles. Refer to “Electrical Connections”.
	3. Unit cycling on high limit.	3. Check for proper air supply across heat
		exchanger and proper gas supply.
	4. Poor thermostat location.	4. Relocate thermostat .
K. Noisy power ventor.	1. Power ventor wheel loose.	1. Replace or tighten.
	2. Power ventor wheel is dirty.	2. Clean power ventor wheel.
	3. Power ventor wheel is rubbing on the housing.	3. Realign power ventor wheel.
L. Fan will not run.	1. Loose electrical connections.	1. Check and tighten wires on fan circuit.
	2. Defective motor or overload.	2. Test for 115v on terminal ACB Heat and
		“L2” if voltage is present replace motor.
	3. Defective control board.	3. Test for 115v on terminal ACB Heat and
		“L2” on the control board, if voltage is not
		present 45 seconds after trial for ignition
		replace board.
M. Fan motor turns on and off	1. Motor overload protection is tripping.	1. Check motor amps against motor name
while burner is operating.		plate, check voltage, replace if found defective.
	2. Loose wiring or connection.	2. Check for 115v between motor leads.
	3. Control board is defective.	3. Check terminal ACB Heat for voltage if
		voltage not constant, replace board.
N. Fan will not stop.	1. Control Board is in flame failure mode.	1. Turn 115v power off to the unit, wait 10
		seconds and reapply voltage to the unit.
	2. Fan improperly wired.	2. Check wiring of fan circuit to wiring diagram.
	3. Defective board.	3. If unit is not calling for heat and board is not
		in a flash code mode, replace board.
O. Not enough heat.	1. Incorrect gas input.	1. Refer to “Operation”.
	2. Heater undersized.	2. Is the heater output sized correctly for
		heat loss of the space. Has the space
		been enlarged.
	3. Thermostat malfunction.	3. Check thermostat circuit, 24v on terminals
		“R” and “W” on terminal strip.
	4. Heater cycling on limit.	4. Check air movement across heat exchanger.
		Check voltage and amps at the fan motor.
		Check gas input to ensure unit is not over
		fired. Check heat exchanger to ensure unit
		is not dirty.
	5. Incorrect orifice sizes.	5. Check orifice size, replace if undersized.
P. Too much heat.	1. Unit is over fired.	1. Refer to “Operation”. Check orifice size.
		If too big replace.
	2. Thermostat malfunction.	2. Check thermostat for operation, to ensure
		circuit open and closes.
	3. Heater runs continuously.	3. Check wiring per diagram; check
		operation at the gas valve, look for
		a short in thermostat circuit.

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