What is a DSI RV Water Heater? (All Explained)

what is a dsi rv water heater

A DSI water heater is a type of water heater for recreational vehicles that activates its heat through a switch. It’s a convenient RV feature that lets you have access to hot water without experiencing the hassle of manually lighting a fire.

Here’s a more detailed and in-depth explanation of ‘what is a DSI RV water heater.’

Definition of DSI


Now, you may also be wondering, ‘What does DSI stand for?’ Well, DSI means ‘direct spark ignition.’ And, a direct spark ignition water heater, as the name suggests, ‘ignites’ a ‘spark’ to generate heat.

It’s a low-voltage ignition system with a gated oscillator to power the spark, a flame sensor to keep the flame going, and a fuel valve that’s kept open when there’s a flame.

While that may sound complicated, it’s actually easy to operate. You only have to turn on the DSI switch and you’re good to go.

So, how does a DSI RV water heater work?

Once you turn on your DSI water heater switch, you are activating your water heater to produce heat, either by propane gas or electricity. It then does its job to heat up your water, and it automatically stops when it reaches the temperature you set.

1. History of DSI Water Heaters

Long before the DSI water heater was invented, people used to light up their pilot flames to produce heat. Many RVs still use the RV water heat pilot, where you use a long utility lighter to manually put the flame to the pilot. But, it’s getting obsolete already as days pass by.

​​That’s because of the invention of the direct spark ignition (DSI) water heater, patented by Ronald A. Gann in 1985.

His invention led to the use of DSI systems in both kitchen and on-the-road appliances like fryers, broilers, furnaces, construction heaters, asphalt pavers, rooftop HVAC units, and RV water heaters.

Today, most newer models of RVs come with the DSI hot water heater.

2. Types of DSI RV Water Heaters and Their Benefits


There are three types of DSI water heaters for recreational vehicles. This includes the propane DSI, electric DSI, and gas/electric DSI water heater, with Atwood and Suburban being the top producers of DSI heaters.

  • Propane DSI Water Heater: This water heater only runs on gas, which is a more cost-effective choice.
  • Electric DSI Water Heater: The electric version of the DSI water heater only works when there’s electricity that can’t be run without an inverter.
  • Dual DSI Water Heater: The dual DSI combination water heater can let you switch between electric and gas options for obtaining heat.

DSI RV Water Heater Maintenance


To keep your water heater with DSI free from problems and make it last longer, regularly perform routine maintenance. Here are some maintenance tips for you:

1. Drain your RV’s water heater tank after every trip

After each trip, you have to get rid of all the water left in your tank to avoid foul odors and unsafe water that could already have bacteria and molds if left for a long time. You can do this by switching your water supply off and removing its drain plug.

But don’t drain it at once– especially if the water is still hot or has high pressure. You might end up being injured at the wrong times!

2. Flush your tank every 6 months

Sometimes, draining your water heater tank isn’t just enough. You’d want to fully flush it out every six months with a flushing tool. Connect this tool to a water hose and spray it around the area.

Focus on the tank’s bottom which usually can’t be fully drained from the valve (because the drainage isn’t placed at the very bottom of the tank) to remove all debris.

DSI Faults: Warning And Troubleshooting


When the DSI fault (also known as DSI Flt) lights up and stays on for a long period, it usually means that there’s a problem with your RV water heater.

A DSI fault on electric and gas water heaters is commonly not extreme, and a little troubleshooting can usually do the trick.

Here are some of the most common reasons why the DSI fault in camper vans are lighting up:

  • Your ECO circuit is not working properly.
  • You left the safety valve open.
  • There may be some leaks.
  • There’s no water in your tank.
  • You may need to add more propane if you’re using the gas type.

In cases like this, you may want to address these and reset your DSI RV water heater. To do this, look for the reset button on your DSI switch. Click this and wait until you hear 3 clicks accompanied by lights.

If this doesn’t work, you may need to look into other causes or call a mechanic to help you out.


DSI water heaters are there to make your RV experience much better. With a simple switch, you can easily turn your heater on!

We hope that we were able to give you the answer to your question, ‘What is a DSI RV water heater?’ as well as the nitty gritty that you have to know about this heater.

So if you do decide to have one, just make sure that you regularly maintain your water heater to avoid further problems in the future!

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