You open the faucets in your RV and the water that flows out is at scalding temperatures instead of the lower, safer but hot temperature of 120 °F or so.
Why does the water get so dangerously hot? What should you do to get the heater to supply hot water at safer temperatures?
This post explains the possible reasons why your RV water heater may be overheating and how you can fix it to avoid injury.
What Causes an RV water Heater to Overheat? (+ Suggested Fixes)
The Thermostat is Probably Faulty
If the water heater is overheating, it’s probably because the thermostat is faulty. The inbuilt thermostat stops the heating of water by the gas or electricity when it attains the preset temperature of the thermostat.
Should it fail, the emergency temperature cut-off will kick in and stop the heating of the water further. It is usually set to activate at a higher temperature than that which the thermostat is set to.
How many Thermostats the Water Heater has
The RV water heater may have a thermostat for each of the gas and electricity systems (in case of a gas/electric heater) or a single one for both systems depending on the design. Consult the owner’s manual for the water heater to confirm which is the case.
Can you Fix an Overheating Heater?
Depending on the nature of the fault and whether you’re handy or not, it can be an easy fix for you to get the water heating working safely again.
Before you attempt to fix it though, check if the water heater is still under warranty. If so, contact the dealer for support as the first course of action.
Use the Owner’s Manual
If you plan to fix it, always consult the water heater owner’s manual for the safety precautions and recommended tools to use.
Depending on the nature of the faulty, fitting a new thermostat, temperature and pressure relief valve, or restoring the water heater headspace depending on the required fix can be done.
How to Replace the Thermostat
The thermostat is usually easy to replace. Consult the water heater manual for instructions on where to find it and how to remove and fit a new one.
Signs of an Overheating Water Heater
If the water heater is overheating then you’ll observe any of the following:
#1. Water extremely hot
The water temperatures will be extremely hot, higher than 120 °F. You’ll not be able to hold your hand under the faucet for a few seconds without causing a serious injury.
You may also have water leaking from the temperature and pressure relief valve
When water is heated, it expands and takes up the headspace at the top of the water tank until the temperature and pressure relief valve is triggered to open and release the hot water.
RV Water Heater Temperature and Pressure Relief (T/P) Valve Dripping? What to Do
If the valve is leaking, it may be that:
#1. Temperature and Pressure Relief Valve Faulty
If the temperature and pressure relief valve is dripping it could also be that it is faulty and needs to be replaced.
#2. Loss of Headspace
Another possibility is that the hot water heater may have lost its head space that allows the heated water to expand too. You can check the water heater manual for instructions on how to reinstate it.
You can establish it again by draining the water heater of the water inside and then filling it again.
If your Rv water heater is overheating, it’s probably because the thermostat is faulty and needs to be replaced.
Depending on the model, the water heater may have one or two thermostats, one for the propane system and the second for the side that uses electricity for heating.
Always consult the RV water heater’s owner manual.