RV water heaters usually run reliably without needing a lot of attention, but sometimes problems occur. If you encounter problems with your RV water heater, before you consult an RV repair service center, you can rule out a few of the most common issues. Some are simple to address. Others may be more complex.
Weather and Seasonal Problems
If you neglect to drain the tank and you store your RV in a freezing climate, a problem is likely to occur. The water in the tank freezes and the tank splits open. Replacement will be required. In the spring you may have another problem if your water heater has a bypass system or kit. If the hoses and the valves that prevent water from filling the water heater tank are closed, no water will enter the tank. If you forget and turn on the water heater, the burner will ignite. The empty water heater tank will get very, very hot. It could melt. Insect or rodent intrusion is another problem. Pests, especially wasps, can enter the housing and build damaging nests. Clean the area and check for damaged wiring or other parts.
Hard water can corrode the inside of the water heater tank. Eventually, the tank can leak. A preventive technique is to install an anode rod. Attach it by screwing it into a replacement drain plug. The rod is eaten away by the reaction that causes corrosion and the tank does not corrode. Check the anode rod at the end of the camping season to note whether or not it has dissolved and needs to be replaced.
Gas Pressure, Supply or Voltage Problems
Incorrect gas pressure can have several symptoms. You may have gas and spark but the water heater does not function, spark alone or an erratic flame. The correct pressure of liquid propane gas is calculated by a measure in Water Column inches of how much pressure is coming out of the gas line and into the water heater. Have an authorized RV service center perform a pressure test, along with a leak test.
The voltage may be low and you may need to correct the power supply. This can be true if you have gas, spark and no function or if you have no gas and no spark.
The flame can be erratic if you need to replace the gas supply, adjust the main burner air shutter, adjust the valve and main burner alignment or if the burner orifice is blocked. As a do-it-yourself project, you may be able to unclog the orifice, but it is important not to enlarge it or change its shape.
If you have no spark and no gas, your thermostat may be faulty. If the thermostat is not seated against the tank, water temperatures may be hotter or colder than you expect and you will need to reseat the thermostat. If you reseat it and temperatures are not responsive, you have a defective thermostat that needs to be replaced. Another situation that may call for replacing the thermostat is if it "chatters" or the temperatures fluctuate.