RV Water Heater Not Lighting? [Types, Reasons & Fix]

The Water Heater is one of the most vital pieces of your RV system. It provides you with hot water on your trips for everything. However, what if your water heater malfunctions or stops working optimally?

Camping without hot water will be no fun. Therefore, you must know the basics of an RV water heater in advance to solve the problems. Besides, it is easy to troubleshoot an RV water heater if you are aware of its primary operating system.

In this article, we will cover a few fundamental issues like RV water heater not lighting, what can be the possible reasons behind it, and how can you solve them. It will help you save yourself from the headache of leaving the camp and running to an RV repair facility.

Types of RV Water Heaters

An RV Water Heater works on two types of fuel – Electricity or Propane Gas. Different types of water heaters use either electricity or propane gas, or both. Thus, to know why your RV water heater not lighting, first, you need to determine which water heater is fitted in your RV. Below we have listed the four main types of RV water heaters.

Manual Propane Water Heater

The majority of RV water heaters are propane based. The manual propane water heater requires you to physically light the propane pilot light, located either inside or outside of your RV. Usually, the pilot light is on your RV rig’s exterior, behind the protective grate or covering. Thus, in a manual propane water heater, you need to light the pilot lights and adjust the water heater to the desired temperature.

Direct Spark Ignition Water Heater

Direct Spark Ignition Water Heater is an alternative to the manual propane water heater and thus uses propane as its fuel. The only difference between a Direct Spark Ignition and a Manual Propane Water heater is that you have the convenience of turning the pilot light with a button’s click or a switch’s flip inside of your RV. 

Most modern-day RVs have direct spark ignition water heaters because of a wide variety of price points. However, the igniters of the DSI water heater require both propane and electricity for proper operation. 

Electric Water Heater

Modern RVs have an electric water heater installed in the RV rig. However, it becomes difficult to work with them in an RV because of the large number of amperes required for their working.

An electric water heater has an electric component submerged in water for heating. It keeps you away from worrying about propane, pilot lights, and other maintenance issues. However, you still need to pay special attention to the pressure that builds up in your water heater.

Tankless Water Heater (Electric or Propane)

The latest water heater technology used in an RV is the tankless water heater working on either electricity or propane. However, an electric tankless water heater needs a large amount of current, so propane tankless water heaters are more popular.

Tankless Water heaters provide a quick and easy supply of hot water. Therefore, they are ideal for a large group of people. However, these water heaters are technically advanced, and you may struggle to troubleshoot some situations, especially while facing low water pressure.

Probable Reasons For RV Water Heater Not Lighting

Several reasons contribute to why your RV water heater not lighting. However, to know the real cause behind it, you must open up the control panel cover and look out for the following possibilities.

1. Spider Web

Not operating the RV for an extended period can make it home to various insects and other small living things. Spiders are the most common living creature that builds a nest in unused areas. They also get into the control panel cover and build a nest around the spark plug. Thus, spider nests can be a reason behind your RV water heater not lighting.

2. Dust And Corrosion

Everything requires regular and proper maintenance once in a while. Thus, if you do not carry out adequate maintenance procedures for your water heater, it might face corrosion and dust accumulation at various technical parts. For example, the thermal fuse is covered in dust, and the tube rusts with time, leading to a water heater malfunction. Moreover, if the spark plug is covered with dust, it might contribute to the RV water heater not lighting.

3. Damaged Spark Plug

A spark plug sparks three times when you turn on the water heater. A spark plug may crack because of aging. Besides, spark plug wears out after some time. Thus, there your RV water heater not lighting issue can be because of a damaged spark plug.

Fixing the RV Water Heater Not Lighting Issues

There are several problems related to the RV water heater not lighting. Some of the common issues associated with the two most common kinds of water heaters, along with their solution, are listed below.

Manual Propane Water Heater

Problem: Pilot Not Staying Lit


  • Ensure the thermocouple is free of soot, centered in the pilot light flame, and screwed tightly to the control valve.
  • Remove and clean the pilot orifice, pilot burner, and tube.
  • Clean the orifice only with compressed air.
  • Do not use drill bits or other abrasive items as they may enlarge the opening.

Problem: The pilot is on, but the main burner is not lighting.


  • Ensure that the valve is on.
  • Check and clean the obstructions in the orifice.
  • If no gas is flowing from the valve when turned on, you may need to replace the valve.

Direct Spark Ignition Water Heaters

Problem: No ignition or nothing happens on turning on the switch inside RV.


Ensure 12 V current is reaching the control board. Make sure that the current is not interrupted by a thermostat or high limit switch with a reset button.

If 12 V is reaching the board with a proper grounding, then make sure the following three things should happen.

  • The board begins discharging high voltage to the igniter.
  • The board sends 12 volts to the gas valve.
  • The board senses the presence of a flame and continues to send 12 volts to the gas valve. If the board senses no flame, it will shut the power off to the gas valve. 

If the board sends the volts to the gas valve, check for the fuse in the panel. If the fuse is okay, then the board is likely defective and must be replaced. Most RV service centers have a circuit board tester that checks for all the three functions mentioned above.

Problem: Igniter sparking but not igniting.


  • Check whether the 12 volts are reaching the valve or not and whether the valve is grounded or not.
  • If 12 volts are reaching the valve, tap the valves lightly as they might be stuck. If nothing happens, the valve might need to be replaced.
  • Check for orifice obstructions if the valve is open, but no gas reaches the burner.

Problem: Ignited but unable to stay burning.


  • Check for wiring connections for the igniter. It may be possible that the igniter is not able to send the flame presence signal back to the board.
  • Ensure that the igniter is centered and can sense the flame. Adjust if required.
  • Clean off the soot or corrosion on the igniter.

Manual And DSI Water Heater

Problem: The main burner is roaring excessively, causing soot around the exhaust port or has a yellow flame.


  • Ensure that the burner tube is free of obstacles like wasp nests, spider webs, etc., clean if needed.
  • If the air/gas mixture is incorrect, adjust the air according to the manufacturer’s instructions until the flame turns blue.


Hot water is essential for carrying out various activities. However, it gets challenging to camp without hot water. Hence, it would be best if you had a regular maintenance schedule for the water heater to prevent issues like the RV water heater, not lighting. A routine checkup saves you from troubleshooting issues while you are on the go.