Electrical System Troubleshooting YES
NO
If it is determined that problem is not fuel related but instead is electrical in nature, follow the boxes until the problem is solved. Then run the unit or a cycle to be sure problem does not repeat.
SECTION
16
16
• Remove primary control cover. • Jump the thermostat T-T terminal on the primary control if not done. • Reset safety switch.
CAUTION Be sure fire chamber is free of any unburned fuel.
Electrical System Troubleshooting troubleshooting
Does burner start?
Electrical Troubleshooting
SECTION
caution
• If the relay contacts pull in but are “chattering”, relay is bad and control needs to be replaced. • If relay contacts pull in and burner runs but still shuts off on safety, replace CAD CELL eye. • If burner starts but stops shortly after (short cycles) without tripping safety switch, check for loose wire and replace primary control.
YES
to test primary control safety shutdown • After burner starts, disconnect one wirelead from the cad cell at the primary F-F terminal. Primary control should shut down on safety after 15 to 45 seconds.
If any problem repeats itself, start over.
Does burner continue to run?
16
Does transformer have good spark? NO
• Check wire contacts. If good, and system has primary control, replace transformer.
YES
YES
Primary Control • Remove the primary control from the burner housing and check if voltage is being supplied to the control at the black and white wires, use a meter. Voltage should be 120 volts. • Do not make contact with transformer springs.
Is 120 volts present? NO
• Reset safety switch. • Check the same white lead with orange lead for power to motor and transformer.
Is 120 volts present?
technical information
Always turn off electrical power when removing or replacing controls and be alert and careful when troubleshooting controls with power on.
• If 120 volts is present and the transformer has a good spark but the motor doesn’t start, the problem can be either the motor or pump. Carefully turn motor fan. If it rotates easily, motor needs to be replaced. If hard to spin, turn power off and remove motor. With motor off the burner, try again. If it doesn’t run, replace motor.
NO
Find and repair open circuit.
Find and repair open circuit.
234 16_Troubleshooting_p295.indd 234-235
F.W. Webb Company
www.fwwebb.com
The F.W. Webb Heating Catalog
F.W. Webb Company
235 3/24/08 4:29:57 PM