Vacuum. This is a good time to vacuum out the burner compartment, check for water leaks and remove debris in the burner ports. Attach the thermocouple and reinstall the burner assembly. Light the pilot following the instructions on the water heater. Check for gas leaks by applying soapy water to joints and looking for bubbles while the main The two thermostats listed below fit our Suburban 12-gallan Propane/Electric water heater (Model #SW12DE). Check the parts list at the end of the Installation & Owner's Manual for your water heater to be sure you order the correct replacement for your model (you can look in the Suburban Water Heater Document Library or the Atwood Mobile Water The HEAT-OFF-COOL should be on OFF. AUTO-ON should be on AUTO. Remove the protective cover and find where you want your thermostat. Drill in place of mounting holes and secure the body to the wall. Use wiring diagrams in your manual to secure wire connections. Determine your type of furnace on the ELEC-GAS switch. Gas Water Heater Thermostat Replacement. Gas water heaters employ a different sort of thermostat system than electric water heaters.Generally speaking, on gas water heaters, the gas control valve, which incorporates both an adjustable thermostat and a heat limiting mechanism, is positioned on the outside of the unit, near the bottom.It may be distinguished from other components by the fact Installing a water heater thermostat for an electric water heater is not a difficult task. You will need to obtain replacement thermostats before you begin. If you are going to the trouble of replacing them, you should replace them both. Removing the Old Thermostat. There are two steps to removing the thermostat assembly. First you need to Step 2: Shut OFF cold water supply to water heater, open hot water faucet, attach hose to drain valve, open drain valve on water heater and drain water. Step 3: Remove access cover and fold back insulation. Step 4: Remove plastic terminal protector. Step 5: Check wires with volt meter/circuit tester for power before attempting to remove the It does not matter if you have a water heater with a standing pilot or electronic ignition. Check the water heater's gas control valve and turn it off. You might also want to follow the gas supply line until you see a shutoff valve. Turn the knob to the OFF position, too. Step 2. Remove the water heater's burner assembly cover. The main thing to worry about with your gas water heater thermostat is the temperature setting. You do not want anyone in your home getting burned. Make sure that you have set your gas water heater thermostat at a proper setting. To replace the thermostat you need to replace the gas valve. We gave you a link to find instructions on doing that. Step2. On the decreased entrance of the water heater find the. mixture control valve/thermostat. 1. Depress and hold the lock tab located under the control knob on the right. 2. Rotate the control knob on the combination gas control valve/thermostat clockwise until "OFF" aligns with the mark on the front of the valve. 3. This article is a step-by-step guide on how to replace the thermostat in your water heater. Table of Contents. Signs A Water Heater Thermostat Is Broken; The first thing to check would be if you have a digital or analog model of your unit and what kind of manual reset button does it have? Digital models require pushin