Water Heater Sizes and Operation

• Larger RVs will typically host a 10-gallon-sized hot water heater, while most other RVs will have only a six-gallon tank. Due to the small size of the water heaters, most RV campsites will offer their own shower and toilet facilities. RVs with showers are often only used when the RV can be hooked directly to a continuous water supply.
  
  

By-Pass Valve

• Installed on the water heater near the inlet valve for cold water, the by-pass valve has the ability to block the flow of water into the RV's water heater. This is especially beneficial when winterizing the RV because draining the tank is easier and less anti-freeze solvent is required to be deposited into the hot water heater. By-pass valve kits may be installed if they were not factory installed.
  
  

Press Relief Valve

• RVs' hot water heaters are equipped with pressure relief valves designed to open when there is excessive pressure in the hot water heater, which is usually caused when water temperature inside the tank reaches 210-degrees Fahrenheit. Once the water reaches this temperature, it has caused the water pressure to reach a measurement of 50 pounds PSI, and the pressure relief valve will then open and allow water to drip out underneath the RV. This occurrence is normal and does not suggest that the valve is defective or malfunctioning. Dripping will cease and the valve will close when the pressure and temperature lowers.
  
  

Use

• When operating an RV hot water heater, it is important to first hook the RV up to a water source and check to make sure the by-pass valve is opened so that the water can fill the hot water heater tank. Turn on one of the hot-water taps in the RV and once the water flows continually with no air pushing through the lines, then the tank is full and safe to operate.
  
  

Maintenance

• In order to properly maintain your RV hot water heater, it is important to follow the operation and safety instructions included in the user manual for the RV. When the RV hot water heater is not being used it should be drained to prevent deterioration by minerals and chemicals in the water and also to prevent bacteria from growing in any water left to stagnate. This is also important in the winter season to prevent the tank from freezing and cracking and requiring repair or replacement.