Buy 120V Digital Temperature Controller Thermostat Board with LCD Display & RTD Temperature Sensor Replacement Part for Pit Boss Pellet Grills Kitchen Cooking Meat BBQ Barbecue (Black): Grill Thermometers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
i think the key here is to not only clean the grill but clean the control panel after every cook. Sometimes stuff drips on it on my vertical and I always wipe it down with a pre-sprayed paper towel. I use the "Totally Awesome" cleaner that someone here recommended that is only a dollar a bottle at Dollar General, that stuff is awesome! In your case I would just buy a whole new controller and clean the outside off before installing.