User Manual

Fan runs, heater does not light.
Open fuel supply
vaves .
Provide proper
gas pressure to
heater inlet.
Check continuity across
switch. If contacts are
open determine cause.
Check for:
proper voltage, blockages
at air inlets or outlet, loose
fan, or low fan speed.
If good, replace backflash
switch.
Are all fuel
supply valves
open?
Is proper
gas pressure
supplied?
Are the
backflash switch
contacts closed?
Does gas
solenoid valve open?
Is proper
voltage
supplied to
valve?
Defective wires or
connections. If good,
replace ignition control.
Defective
valve.
Does ignitor
spark?
Is high voltage
lead securely
connected to
ignition control
and ignitor?
Connect High Voltage
Lead
Is ignitor
properly
gapped?
Check igniter gap
Regap to 3/16 in.
Is ignitor gap
positioned
toward burner
orifice?
Reposition igniter.
(See Service Instructions)
23
TRADESMAN HEATER
Problem
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
NoNo
No
Determine if ignitor receives high voltage: -- Disconnect ignition lead from ignition control. -- Position a screwdriver tip about 3/16 inch away
from ignition control where lead was connected .
-- WITH GAS OFF, start the heater. -- If no spark is seen, replace the igntion control. -- If spark is seen, reconnect igntion lead to control. -- Disconnect the lead at the ignitor. -- Hold the lead about 3/16 in. from a grounded
section of the heater.
-- WITH GAS OFF, start the heater. -- If no spark is observed, replace the ignition lead. -- If spark is observed, replace the ignitor.
No
Yes
Check the burner orifice
for blockage. Clean or
replace the orifice .