Disclaimer: Due to the dangerous nature of working with electricity, we highly recommend hiring a qualified expert with the training and tools to help troubleshoot and install replacement parts safely. This information is not intended as a comprehensive guide. If you choose to perform any troubleshooting or replacement yourself, you do so at your own risk. Remember to ALWAYS disconnect the appliance from its power source before disconnecting any wires or attempting service tasks.
What is Voltage?
Voltage is a unit of measurement for the force that pushes electricity to move through a circuit. Voltage measures the force of the push needed to transport an electric charge between two points; this is known as the electric potential difference. In troubleshooting a stove or fireplace, you will mostly be measuring the voltage between the ends of a wire.
There are 2 types of electricity: Alternating Current (AC) or Direct Current (DC). The standard electricity supply for households in the United States is 120 Volts of Alternating Current.
|The symbol for AC voltage on your meter looks like a “V” with a wavy line.|
|The symbol for DC voltage has a dashed and solid line that looks like a mini road.|
Voltage in stoves and fireplaces:
Many parts run on the full voltage provided by the wall outlet in your home. However, certain parts run on a reduced range of voltage often measured in millivolts. You will need to understand what type and range of current the part uses to test it effectively.
This type of test measures the part’s ability to mechanically perform its job in your heating source.
Using a multimeter to measure voltage is a reliable way to determine whether enough electricity is reaching a part to enable its function. Following the flow of current through a circuit helps to narrow down which part to bench test or bypass in your troubleshooting efforts.
This test works great on many parts including:
- Control boards
- Blower motors
- Feed motors
How to measure voltage:
This type of test requires an understanding of how the electric circuit functions and should not be performed without training. If you do not feel comfortable performing these diagnostic steps, we strongly recommend consulting a licensed technician in your area.
Tools you may need:
- The owner’s manual for the stove
- Wiring diagram
- A screwdriver set
- Needle nose pliers
- An ohmmeter or multimeter
- Lighter or hairdryer
Example #1: Igniter
If the igniter in your pellet stove isn’t heating up, the first step is to make sure it is receiving power from the control board. Be sure to set the meter to the type and range of current the part uses, and start with the stove unplugged from the wall. Connect the red and black leads of the meter to the stove wires that lead to the igniter. When you plug the stove back in and turn it on, the multimeter should register 115-120 volts. If the igniter receives this power, then you know to concentrate on the igniter rather than other components in the igniter circuit.
Example #2: Convection Blower
Checking a convection blower circuit for voltage helps to narrow the problem down to the blower motor, a snap disc, or the power source. Unplug the stove or fan before working with any wiring, and remember to set your multimeter to the correct range, usually 115-120 volts of AC power. If the blower wiring uses simple clip connectors, you can directly connect the leads of the multimeter to the wires leading to the blower. If the blower uses a Molex plug connection, you can insert the probes of the multimeter to make contact with the pins of the plug. You may need to apply heat to the snap disc with a lighter or hair dryer to get an accurate reading if the blower is heat activated.
Example #3: Thermocouples or Thermopiles
Set your meter to measure millivolts. Connect the leads of the multimeter to the ends of the thermocouple or thermopile. Heat the tip of the part with a lighter for about 30 seconds. A good thermocouple should produce about 25-30 millivolts. A good thermopile generates roughly 250-750 millivolts. If the millivoltage is lower than the appropriate range, you should replace the part.