Heating Troubleshooting Checklist

Below is a list of common problems and things to check before having to call a professional for a non-functioning heating system.

THERMOSTAT CHECK

- Is the system selector switch in the "heat" position?

- Is the temperature set at least 3 degrees above current room temperature?

- If your thermostat is electronic, are the batteries charged? Is the display showing?

- Forced Air Furnaces Only. If your thermostat has a switch to control the furnace fan, switch the fan "ON". (This switch will usually be located at the bottom of the thermostat, closer to the left side and will be marked "ON" and "AUTO".) Listen to hear the furnace fan coming on. If you cannot hear the fan, go to one of the supply registers and see if you can feel any air coming up. If the fan is not running, there may be no power to the furnace.

If the thermostat is set properly, next step is to check to see that there is power to the furnace.

ELECTRICAL CHECK

- Your heating system may be equipped with an emergency shut-off switch for the furnace. If your system is so equipped, locate it and make sure it is turned on. In most homes the emergency shut-off switch looks just like a regular light switch and will be located on the side or close to the furnace. (Sometimes there is a second switch at the top of the basement stairs) It is quite common for this switch to be turned off accidentally. If the switch is ON, but the fan still doesn't operate, proceed to the ELECTRICAL PANEL CHECK.

- Some heating systems also have emergency cut-out switches that are activated when a door or service panel is removed. Often the furnace door is not replaced properly after a filter cleaning and the cut-out switch will prevent the furnace from coming on. Check to make sure all access doors are properly secured and fitted.

ELECTRICAL PANEL CHECK
Here you are going to make sure that the main power is on to both the furnace and air conditioner. Locate the breaker or fuses in your home's main electrical panel for the furnace and air conditioning unit. Make sure the breakers are not tripped or the fuses are not blown.

- If your home has breakers, check to see if any are tripped. If a breaker has been tripped it will be in a position that is between ON and OFF. Reset the breaker (turn all the way OFF, then back ON).

- If your home has fuses, check to see if the fuse for the furnace is blown. If so, replace it with the SAME SIZE fuse. Do not increase the size of the fuse.

WARNING: If a breaker keeps tripping or a fuse keeps blowing, you should contact a qualified service technician to inspect your system to determine why you are having problems.

ELECTRICAL CHECK SUMMARY

If you have determined that there is power to the furnace and you are still not getting any heat, look for any troubleshooting guides that came with the furnace for any additional help. If all else fails, then it is time to call your service contractor.

IGNITION CHECK

If your unit seems to be operating, but not producing any heat, the furnace may not actually be firing. If this is the case:

Check the following:

- Do you have fuel? This may sound a little silly, but you'd be amazed at how many service calls are caused because the furnace ran out of fuel. If your unit is oil, or propane fired check the level of fuel in the tanks. If you ran out of fuel, ordered some more, and now your furnace will not start, your unit may have to be reset. Some systems have a red reset button on the burner. Other systems can be reset by turning system power off then back on. If it is oil-fired, the pump may need to be primed. Check with a service technician.

- If your furnace is a gas, standing pilot (one that is on all the time) look inside your furnace to see if you can see it. If not follow the instructions on the furnace to light the pilot. If after following instructions and the pilot will not light or stay lit, call a service technician.

- In most furnaces and boilers, you can tell when the fuel is being ignited. Turn the furnace off at the thermostat and go to the furnace. Have a friend of family member turn the furnace on at the thermostat, can you hear the furnace ignite the fuel?

OTHER COMMON PROBLEMS

- Broken or extremely loose fan belt.

- Bound or tight blower motor - With power OFF to furnace try to turn blower shaft (should spin freely).

- Bound gas inducer motor - If the furnace isn't working but the inducer is very hot, it could be stuck.

- Broken gas igniter.

- Termination kit for Gas, PVC sidewall vented furnace is blocked by snow or another obstruction.

- A completely clogged air filter can cause a no heating problem.

PILOT LIGHT GOES OUT

Pilot lights do go out occasionally. Some people even shut them off in the summer. Every homeowner should know how to light his or her pilot. It isn't too difficult and there are usually instructions printed on the equipment itself. (Sometimes on the back of the furnace door.)

* Remember, this is for standing-pilot systems only. Many of today's systems don't have a pilot light; they use spark or electronic ignition.

Here is a brief guide:
Always follow the instructions on the appliance before anything else.

1. Turn off furnace, boiler, or water heater at thermostat or power switch.

2. Locate the gas valve and turn knob from "on" or "off" (depending where it was) to "pilot" position.

3. Hold down red button, which sends gas to the pilot burner.

4. At the same time hold match to pilot burner. (Just follow the small pilot tubing to end. Sometimes a long match is needed, you can use needle nose pliers to hold match.

5. On some equipment, you may need to move a small metal door or panel for access.

6. Light the pilot but do not let go of button.

7. Continue holding button for 60 seconds.

8. Now let go of button, pilot should stay lit.

9. If not, you need to call for service.

10. Turn gas valve knob back to the "on" position.

11. Turn on appliance, turn up thermostat, main gas should light.

12. Remember to put back metal cover if your system had one.

If your pilot light goes out more than once a season there could be a problem. Possible causes could be:

- Bad or loose thermocouple

- Bad gas valve

- Poor pilot flame - low gas pressure or blocked orifice

- High winds or downdraft

- Badly cracked heat exchanger

- Improper venting; flue or chimney problems

- Gas shut off or out of propane

So, if your pilot goes out, follow the instructions and try lighting it yourself. If it doesn't light or stay lit then call for service.

OIL BURNER KEEPS TRIPPING THE RESET BUTTON

That would be the little red button on the box at the oil burner itself. If your oil burner stops running the first thing you should check is the reset button. If you press it and the burner fires up then that was the problem. If the button should trip again then there is a definite problem and you should schedule a service call immediately. Do not keep resetting the button and ignoring the problem.

Now, what is this button and why does it trip?
It is a safety device. It shuts the burner down when it thinks there is a problem. It is on the primary control and is hooked-up to a cad cell - a light sensor (The same thing that turns outside lights on at dusk).

On a call for heat, with the burner running, the cad cell senses the light of the flame. If it stops sensing the light of the flame, it causes the red button to trip, shutting down the burner before any significant damage is done.

Next question. Why would the sensor stop sensing light while the burner is running?
Many reasons. Almost all of which require a service call.
Below is a list of possible causes and things to check. Items in blue usually require a service call. Items in red however can be addressed, even fixed by the homeowner.

- Faulty or dirty cad cell

- Faulty primary control

- Bad or weak ignition transformer

- Bad burner motor

- Bad fuel pump

- Blocked oil filter, strainer or nozzle

- Delayed oil valve not opening (some units)

- Cracked electrodes

- Improperly set electrodes

- Air in fuel line

- Burner running with a very high smoke

- Burner sooted-up

- Loose electrical connections

- Damaged flexible coupling

- Water in oil tank

- Out of oil - Have your tank filled

- Chimney blocked - Have it cleaned

- Closed oil valve - Open valve

- Air, Pump not primed - Prime pump - may need to call for service

The bottom causes in red are common problems and can be addressed by the homeowner. Try to check for these conditions first before calling for service.

PLAN AHEAD TIP
You should get to know your heating system BEFORE it stops working for you. Listen for the various sounds it makes, how long it stays on and where everything is. If you take a few minutes to prepare, you'll be much better prepared if something goes wrong. If you're unsure where things are, ask your service technician for a tour on the next maintenance inspection.

We hope this helps. Remember, these are just rough guidelines and not all possible situations are covered.