A Step-By-Step Guide To Waste Oil Furnace Troubleshooting

At Interstate Energy, we wanted to make waste oil furnace troubleshooting simple and easy. Our comprehensive guide covers all of our available models, from the CB-140 to the CB-5000. Just use the process of elimination to identify the problem and the steps you need to take to address it. Let’s dive into a few of the more common problems.

The Burner Won’t Run

When your burner refuses to run, there are only a few possible causes that you should check for. Some of these causes have quick and easy solutions. If the green power light is NOT ON, run through the following checklist:

• Is the circuit breaker or main switch open? Simply close the circuit breaker or the switch.
• Is the fuse or the circuit breaker blown? Contact your Clean Burn professional to get the electrical system checked out safely.
• Is the burner cable damaged or not plugged in properly? Check on the condition of the burner cable and plug the cable in properly. If it is damaged, contact the pros at Interstate Energy to get quick professional attention and next-day delivery.

In some instances, the burner may not be running at all while the green power light is ON. If this is the case, you’ll need to check for a few possible causes:

• Has the oil primary control shut down on safety reset? If this is the case, you’ll need to reset the oil primary control. To do this, follow the instructions in section 7 of the appropriate furnace manual.
• Is the wall thermostat not operating? Check on the condition of the wall thermostat and the attached cable. If either is damaged, you’ll need assistance from your Clean Burn professional.
• Is the heater block failing to heat up? Place the back of your hand near the back of the burner to feel for heat. You can also use a thermometer for a more accurate reading. The heater of the CB-140 model should be at least 120 degrees F. The heater for all other waste oil furnaces should be at 140 degrees F. Wait 15 minutes to see if the heating block heats up. If it fails to heat up, you’ll need to call your authorized Clean Burn dealer.
• Has the F-120 proving switch not closed? If the heating block heats up, check on the red wire at the F-120 proving switch for power. If there is no power, you may need to replace the proving switch.
• Have the oil primary control terminals been wired incorrectly or have they been damaged? Check on the “F” terminals to see if they are connected properly and check the voltage. For each furnace, the voltage must be at 115 volts. A damaged oil primary control will have to be replaced.
• Have the L-200 or L-290 limit switches been opened? In this scenario, test the switches for power. Power should be indicated on both sides of the switch. For further instructions, see section 7 of the appropriate furnace manual.

We hope that these waste oil furnace troubleshooting steps help you identify the burner problem. If you can’t, then you’ll need to contact your authorized Clean Burn dealer for professional help.

The Burner Ignites, But Fails To Stay Running

In this scenario, there are only a handful of possible causes that you’ll need to check through. Run through the following list of possible causes:

• Is there a fuel delivery problem? If so, proceed to the cad cell.
• Is the cad cell dirty? Clean and check the condition of the cad cell.
• Are the cad cell wires loose? Make sure those wires are connected properly at the “F” terminals on the oil primary control.
• Is the cad cell damaged or are the cad cell wires damaged? If you trust your capabilities, replace the cad cell and the wires. If the damages are from the furnace heat, then you’ll need to clean your entire furnace (combustion chamber, flues, and stack). You should also check for a backdraft from the exhaust fans in your building.
• Is the primary control not receiving the right ohm signal from the cad cell? If so, then disconnect the yellow wires and start the burner to check the ohm reading from the cad cell. If the reading exceeds 500 ohms, then you may need to reposition the cad cell and the retention head.
• Is there air in the suction oil line due to leaks at the fittings? If this is the case, you may need to reinstall and properly seal the suction line fittings. You can vacuum test the pump by following these procedures.
• Is there air trapped in a high point in the pressure oil line? Trapped air could indicate that you need to bleed the air out of the pressure oil line.

In some cases, the burner might ignite and continue to run, until it shuts off on reset sometime later in the day/night. If this happens to you, then run through the following waste oil furnace troubleshooting tips:

• Is there air in the fuel supply? Prime the pump. If it fails to prime, move onto the next troubleshooting section.
• Is the primary control not receiving the proper ohm signal from the cad cell? If you think this is the root of the problem, you’ll want to check on the ohm signal by using the steps listed above.
• Is there insufficient air pressure? You’ll need to adjust the air regulator for proper air pressure. Never turn the air compressor off while the furnace is operating.
• Is the heater block cold? A cold heater block could mean you should avoid shutting off power overnight. If you do, then the burner will not restart the next day. Instead, turn the wall thermostat to OFF, which will keep the heater block hot.
• Are the electrodes fouled? Oil residues can build up on the electrodes and retention head. If this is the case, you’ll need to clean the electrodes and retention head. Further instructions are provided in section 8 of the furnace manuals.

If the burner problems persist, you may need to call in the professionals at Interstate Energy for help. Just to be sure, you should run through the remaining waste oil furnace troubleshooting lists.

The Pump Will Not Prime

If your pump fails to prime even when the pump motor is running, you’ll want to look into some of the following causes.

• Is there a leak in the suction line? You’ll want to make sure the suction line is properly installed and the fittings are 100% airtight. For more in-depth instructions, see section 4 of the furnace manuals.
• Is the pump not installed? If the pump has not been properly installed, it may fill with oil during the priming process. Make sure the pump head is filled with oil prior to starting the pump. See section 5 of the furnace manuals.
• Are the pump gears dry? If so, fill the oil line and prime the pump.
• Is the pump seal damaged? When the pump is turned off, wipe your finger on the bottom of the cylinder at the pump shaft. If there is oil on your finger, then the pump seal is damaged. You’ll need to replace the pump or replace the seal. You may also want to install a mini-accumulator in the port of the canister filter to prevent pressure build-up.
• Is the ball valve closed? Open the ball valve on the suction line.
• Is the canister filter dirty? Clean the canister filter.
• Is the check valve dirty? Clean the check valve.
• Is the pump damaged/worn out? Replace the pump.

If the pump fails to prime and the pump motor is not running, there are two possible causes that you’ll need to check.

• Is there no power on the pump circuit from the burner? If there’s no power, try to start the burner and adjust the air pressure regulator to 15 PSI.
• On the CB-140 burner, check for power at the wires on the air pressure switch. If there is no power, replace the burner motor. If there is power at the air pressure switch, you’ll need to replace that switch.
• On all other waste oil burners, check for the amber “pump” light on the burner. If it does not come on, there is a problem with the pump circuit in the burner. Check for power in the brown wire on the air pressure switch. If there is no power, replace the burner motor. If there is power at the brown switch, replace the air sensing switch.
• Has the pump motor shut off on thermal overload? Your motor has shut off because it is too hot. At this point, it’s best to contact the repair experts at Interstate Energy.

Fan Motor Runs Constantly Or Can’t Run

This is one of the easier steps in waste oil furnace troubleshooting. Fan motor problems will typically have only 5 probable causes. It is possible that:

• The blower motor circuit is wired incorrectly.
• The blower relay is stuck in the closed position.
• The fan/blower switch is defective.
• The blower motor has overheated and shut down on thermal reset.
• The blower relay won’t close.

Regardless of what is causing the problem, it’s best to contact your waste oil furnace providers for any fan motor issues. Fan motor problems can sometimes be overly technical, so they are best left to the experts.

Skip The Waste Oil Furnace Troubleshooting With Expert Support

At Interstate Energy, we can make your waste oil furnace troubleshooting worries a thing of the past! We strive to provide unbeatable customer service to help with all of your waste oil recycling and heating needs. With 24/7 phone support, on-site maintenance, and next-day parts delivery, we’ll make your troubleshooting process incredibly easy!

Contact the professionals at Interstate Energy today for a better waste oil furnace experience.