Boards Switches Sensors

Depending on your Lennox pellet stove make and model, there are different control boards/circuit boards for correct replacement. The circuit board essentially controls all functions of the stove during start-up, operation, and cool down. We highly recommend a surge protector to be in place to prevent voltage spikes from harming the control board when the stove is plugged in. Currently we carry the Lennox 16053941 touch control board for the Optima, Profile, and Traditions stove models, the H5978 control board for the Winslow PS40 and PI40, and the H7626 control board for the Bella Cast model.

Lennox models such as the Optima 2, Optima 3, Profile 20, Profile 30, Profile 30 Insert, and Traditions stove models will use a Photoeye which acts as a proof of fire safety switch. The photoeye looks through an amber lens in the pellet drop chute and detects the light from the fire during the start-up cycle. Once light is detected, the photoeye gives signal to the control board allowing the stove to start feeding fuel as it goes from start-up into normal operating mode. If at any point during operation the photoeye stops detecting light from the fire, it will give signal to the control board and shut down the auger feed. It's important to routinely inspect and clean the photoeye and photoeye amber lens to ensure proper operation. If your stove is not feeding pellets after the start-up cycle or if your stove is intermittently shutting down, we will want to take a closer look at the photoeye. See our video below to learn more about the photoeye and best practices for cleaning and servicing.

Lennox pellet stoves will have limit switches and a vacuum/pressure switch which are designed as safety sensors in your model. There are several variances in switches depending on your models. The High limit switch is a normally closed snap switch that will open if temperatures exceed the limit point. When this switch trips it will shut down the fuel feed. Most common causes for this switch to trip would be ash blockage in the stove/venting causing high flames and pellets backing up in the burnpot and up the drop chute. The other would be the convection fan blower not operating correctly or not operating at all to disperse the heat into the room.

Low limit switches are normally open, closing to make connection once the indicated temperature is reached. Low limit snap switches are often used as the Proof of Fire switch to lock in the auger feed after start-up, exhaust limit switch to shut down the exhaust fan once the stove is cool, and on the convection fan blower to turn that blower on once the stove is warm enough. Take a look at our videos below for further information on limit switches/snap switches/thermodiscs.

The Lennox vacuum switch, also referred to as the pressure switch or low draft switch, senses pressure in the firebox and exhaust. As a safety sensor, the vacuum/pressure switch will shut down the fuel feed auger if proper pressure is not sensed in the firebox or exhaust. Most common areas to check when seeing a vacuum switch error will be the front door gasket, ash pan gasket, and glass gasket to ensure there is proper seal. From there ash accumulation in the stove, exhaust manifold, and exhaust venting should be checked and cleaned. Additionally, if our combustion blower is not running at proper voltage, it will not be able to lock in the vacuum switch. We offer several vacuum switches for Lennox models in the event the switch itself is faulty and needs to be replaced. Learn more about vacuum switches and troubleshooting in our video below.

FOR TROUBLESHOOTING ONLY, we can bypass a safety switch to determine where the issue may be. See our video below on how to troubleshoot switches and sensors with a jumper wire.

Looking for a Lennox control board, limit switch, or safety sensor you can't find? Please contact us for order inquiries.