If your motorhome has a hydronic heating system, also known as Aqua-Hot, this is an additional RV system to learn about and maintain.  This is one of our favorite upgrades in our motorhome.  Having one on your motorhome adds approximately $7,000 to the value of your coach.  If you are shopping for an RV this is an option you will want to would definitely consider.


10 Important Things to Know About Your Aqua-Hot System | An Aqua-Hot is a Hydronic Heating System for your RV | www.streetwander.com



10 Important Things to Know About Your Aqua-Hot System

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Here is a simplistic Youtube Video to help you understand what an Aqua-Hot can do for you.


Recently, Bryan attended the certified technician training for Aqua-Hot systems.  Since we have an Aqua-Hot, he wanted to learn more about it and make sure we were using and maintaining it correctly. He says the class was very informative and a great asset to his cadre of skills in his RV life. If you would like to take the same class you can travel to Colorado to take it at the Aqua-Hot training center.

After attending this training, we wanted to share tidbits that can help you in using and maintaining your Aqua-Hot system.


What is an Aqua-Hot?

An Aqua-Hot is a miniature boiler that heats up boiler type antifreeze (propylene glycol) to deliver heat to your motorhome in the form of interior heat and endless hot water.  It runs on your coach’s diesel fuel system or propane.

The Aqua-Hot system does three things depending on model:

  • Provides heat for preheating your engine – If temperatures drop below 40 degrees and you need to travel, you will need to preheat your engine using your Aqua-Hot for approximately an hour to make sure you are ready for the road. The Aqua-Hot can preheat an engine from 30 to 90 degrees in one hour.
  • Provides heat for your living space – this heat is very even and consistent front to back, top to bottom.
  • Provides heat for endless hot water.

The following tips can help you understand the needs of your Aqua-Hot and keep the system happy.

  • You can leave on your electric hot water to help your Aqua-Hot be more efficient and use less fuel.
  • Your antifreeze level must be maintained monthly to the levels designated on the side of the fill tank. If your reservoir tank registers empty, it is not enough to just fill the system, you may have to open the bleeder valve to release air out of the tank.
  • It is better to use your Aqua-Hot than to let it sit. The diesel fuel left sitting too long can clog your nozzle.
  • Run burner and heating zones monthly to keep your Aqua-Hot running smoothly.
  • Perform maintenance on your burner annually. The best time to do this is in the spring if you have winterized your coach.  This will help your system run smoothly for all your summer adventures.


You can get the maintenance kit if you feel you can do it yourself. Bryan says it’s a hard job and requires a certain amount technical knowledge to do it.  This handy list of RV tools can make sure you have the tools you need when doing RV maintenance yourself.

If storing your RV for the winter, you must winterize this system. You must use your typical winterization antifreeze to avoid damage to your system. Blowing air to clear the water from the system will not work. Not winterizing correctly can damage your system and could become a very expensive repair.

Be sure to check your propylene glycol annually with a refractometer to make sure to verify your solution is between 40 – 50% or at a -10 degrees.

If you are traveling and your Aqua-Hot won’t come on (start) three common reasons are:

The fuel tank may be too low.

The glycol antifreeze level is below the sensors

The power source may not be enough.

You should never buy a commercial showerhead for your RV because the output of gallons per minute is greater than the Aqua-Hot can produce hot water. The temp of the hot water is preset and not adjustable, so if you are experiencing less than desirable hot water check your showerhead.

Servicing your Aqua-Hot

If you need service on your system be sure to only go to an authorized service center for repairs. Authorized service centers have certified-trained technicians to service and repair this unique system. Click here to find an authorized service center near you.

The Aqua-Hot website is filled with lots of information to help you if you need it.  You can download your manual, register your unit, find service if you need it and even call Aqua-Hot and talk to a tech about problems you may be having.

We really enjoy having this system on our RV.  It is a more complicated system to understand but wouldn’t travel without ours now that we have it!  Also, if you are still shopping for an RV, consider a coach with this system, it is a very nice addition to your RV lifestyle. 😊

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