HIGHLAND RIDGE OPEN RANGE 308BHS - Water Heater Thermostat Replacement

HIGHLAND RIDGE OPEN RANGE 308BHS – Water Heater Thermostat Replacement

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Complete repair guide for the HIGHLAND RIDGE OPEN RANGE 308BHS – Water Heater Thermostat Replacement.

Parts & Tools You’ll Need

Step 1: Diagnose Water Heater Issues and Prepare

Start by identifying whether your water heater is failing to heat, heating inconsistently, or shutting off prematurely—all common thermostat failure symptoms. Turn off power at the main breaker and the propane supply valve, then allow the tank to cool completely for at least two hours before proceeding. Drain the water heater by opening the drain valve at the bottom of the unit into a bucket, and inspect the exterior for any signs of corrosion, leaks, or damage to the access door. Document the current water heater model number and serial number (typically found on the rating plate) to ensure you order compatible replacement parts. Gather your tools: a screwdriver set, adjustable wrench, the Anode Rod Socket Wrench 1-1/16″, needle-nose pliers, a multimeter, and the specific replacement parts for your model.

Step 2: Remove Water Heater Access Door Assembly

Locate the water heater compartment on the exterior of your 308BHS, typically positioned on the passenger side of the trailer. Remove the four exterior fasteners securing the access door using your screwdriver, then carefully pull the door away from the unit to expose the internal components. Inspect the foam seal around the door frame; if it’s compressed, cracked, or missing, plan to install the Water Heater Door + Foam Seal Kit during reassembly. Note the routing of any gas lines, electrical connections, or control wires before proceeding further—take a photo with your phone for reference. Set the door aside in a safe location where it won’t be bent or damaged.

Step 3: Disconnect Electrical and Gas Connections

Verify that the main power breaker is OFF and the propane valve is in the closed position before disconnecting anything. Carefully disconnect the electrical connector from the thermostat terminal block, noting the wire positions—the red wire connects to the heating element circuit and the black wire to the gas valve control. Disconnect the gas line from the gas valve by turning the compression fitting counterclockwise with your adjustable wrench; be prepared for residual gas odor and allow ventilation. If your model includes a thermocouple, gently unscrew it from the gas valve using needle-nose pliers or a small wrench—this is a fragile component that controls pilot ignition safety. Take photos of all connections before removal to simplify reassembly.

Step 4: Remove Old Thermostat and ECO Components

Locate the thermostat sensor probe, which extends into the water tank through a brass mounting block on the side of the heater. Unscrew the thermostat mounting nut (typically located behind the control panel area) using your adjustable wrench and carefully withdraw the thermostat and its probe from the tank opening. Remove the Suburban Water Heater ECO (high-limit thermostat) by unscrewing its mounting bracket—this safety device sits independently and prevents overheating by shutting down the heating element if water temperature exceeds safe limits. Inspect the sensor probe for mineral buildup or corrosion; if heavily scaled, soak it in white vinegar for 15 minutes before installing the replacement. Do not discard the old thermostat until you’ve confirmed the replacement is functioning correctly.

Step 5: Install New Thermostat and ECO Assembly

Insert the Suburban 161109 Water Heater Thermostat probe into the tank opening, ensuring the sensing bulb sits fully inside the tank for accurate temperature detection. Secure the thermostat mounting nut by hand-tightening it, then use your wrench to snug it firmly—do not overtighten, as this can crack the brass fitting; aim for 12-15 foot-pounds of torque. Mount the new Suburban Water Heater ECO (high-limit thermostat) in its bracket beside the primary thermostat, positioning it so the sensor probe is fully submerged in the water tank. Connect the ECO’s control wires to the corresponding terminals on the control module; the red wire handles the shutoff circuit and the black wire completes the ground path. Verify that both thermostats are secure and their probes are not touching each other inside the tank, as this can cause erratic temperature readings.

Step 6: Reconnect Gas Valve and Electrical Systems

Install the new Thermocouple Replacement Kit by screwing the brass fitting into the gas valve until snug—turn it by hand first, then use needle-nose pliers to tighten an additional quarter-turn. Reconnect the gas line to the gas valve by threading the compression fitting clockwise and tightening with your adjustable wrench; hand-tighten first, then snug with the wrench for a leak-free seal without over-torquing. Reconnect the electrical harness to the thermostat terminals, ensuring the red wire connects to the heating element circuit and the black wire to the ground/gas valve control circuit. Test the connection by gently tugging on the connector to confirm it’s fully seated. If your unit includes a 120V heating element, verify that the Heating Element 120V connection is dry and clean before restoring power.

Step 7: Perform Final System Testing and Verification

Close the water heater drain valve and refill the tank by opening the cold water supply; listen for any gas leaks or unusual sounds coming from the compartment. Restore power at the main breaker and turn the propane valve to the ON position, then set the thermostat to approximately 110°F and wait 15 minutes for ignition. Listen for the ignition spark and smell for a brief propane odor as the pilot light ignites—if you smell persistent gas, immediately turn off the propane valve and check all connections for leaks. After 30 minutes of operation, feel the hot water line exiting the heater (it should be warm but not scalding), and verify that water temperature stabilizes at your set point. Reinstall the Water Heater Door + Foam Seal Kit, ensuring the seal compresses evenly and the door fasteners are snug but not over-tightened; check for proper operation over the next 24 hours to confirm all heating modes are functioning.