How To Replace an RV Water Heater Thermostat

TheRVgeeks Repair 16 Comments

Over the years we’ve shared quite a bit about maintaining an RV water heater. Last year we even performed an internal inspection using a borescope. But this is the first time we’ve had to share a repair project.

Actually, “project” seems like too strong a word for what’s involved in replacing the thermostat on the electric side of our Suburban water heater. It was so easy that virtually anyone can do it in just a few minutes.

Hot water is one of the main things that separates us self-contained RVers from our hardy, tent-dwelling fellow campers. Even though tenters probably consider it to be a luxury, we have to admit that we’re spoiled enough that it would be hard to live without.

Water heaters aren’t nearly the most-complicated systems on most RVs. That distinction usually goes to RV refrigerators. The most complicated problem we’ve ever dealt with on the heater (actually it was the one on our first RV) was a “popping” sound coming from the propane burner. That turned out to be a cracked crystal on the propane orifice.

This time, we’re having an issue with the electric side of the heater. Watch the video to see what our symptoms were, and how we resolved the situation.

Our water heater may be different than yours. We have a 12-gallon bi-fuel (propane/electric) model. Some of the smaller Suburban units have a different set-up, with the same electric-side thermostat as ours, but a completely different thermostat design for the propane side. And Atwood heaters are completely different than Suburbans.

But the symptoms of a failing thermostat may be similar, as ours started off with the water not getting as hot as it should when heating on electric.

Regardless which brand of water heater your rig has, this short video will hopefully give you some idea what to expect, and what to do, if your hot water isn’t so hot.

Recent & Related Videos:

Featured & Related Products:

The two thermostats listed below fit our Suburban 12-gallan Propane/Electric water heater (Model #SW12DE). Check the parts list at the end of the Installation & Owner’s Manual for your water heater to be sure you order the correct replacement for your model (you can look in the Suburban Water Heater Document Library or the Atwood Mobile Water Heaters Support Center (lower right side of page) if you don’t have your manual handy).

Check out our Favorite Gear page for all of our favorite RV equipment that we use ourselves and recommend to friends.

We're handy RVers, not professional technicians. We're happy with the techniques and products we use, but be sure to confirm that all methods and materials you use are compatible with your equipment and abilities. Regardless of what we recommend, consult a professional if you're unsure about working on your RV. Any task you perform or product you purchase based on any information we provide is strictly at your own risk.

We sometimes receive products for evaluation at no cost, and The RVgeeks are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites. But our opinions are our own, you won’t pay an extra penny, and we only link to products we personally use, love and can recommend to friends with complete confidence.

Comments 16

  1. Troubleshooting and ordering took longer than the repair – those are the way snags ought to be.

    I see that you tested your fix and it worked. Did you consider cleaning the tank a bit so the new thermostat would have an excellent contact?

    1. Post

      Hi John! That hadn’t occurred to us, as we think it’s physical contact vs electrical contact that makes the thermostat work. Of course we might now have to remove, clean and re-install it to find out for sure!

      Speaking of cleaning the water heater, we just reached the 1-year anniversary of our borescope inspection & cleaning video. So we loaded up on vinegar and a new anode rod, and went out a couple of days ago to video the 1-year follow-up. We wanted to see what the condition of the tank was in back-to-back annual borescope inspections for the very first time. What we found surprised us, and might surprise you, too. But you’ll have to wait for the video to find out! How’s that for a teaser? LOL We’ve got it penciled in for next month, so you won’t have to wait too long. :)

      1. “How’s that for a teaser?”

        It pretty good. Okay, I’m going to be looking forward to the video. But I’m willing to bet that you now have more vinegar than you know what to do with.

        P.S. you heading south this winter?

        1. Post

          Not only staying north, but about to make a mod to our rig to make it easier to stay comfortable in cold weather. Of course there will be a video. Have you got this place bugged? ;-)

          1. REALLY looking forward to your ‘keeping it warm” mod.

            I’ve been to Yellowknife many times and talked to several passengers who went to see the Aurora. One of my dreams was to prep the RV for northern ops and take Kathy to Aurora Village to view (and photo) the Northern Lights.

            However when the temperatures get even 5° below freezing my coach get very cold very quickly and little problems multiply.

            I’ve decided that a winter RV trip to Northwest Territories best be done by the right vehicle; or airplane.

          2. Post
  2. From a plumbers son…what a fine job you did with your tutorial for everyone to get a little better on the DIY side of this keep them ” running and working “. The bride and I as empty nesters have just purchased our first MH and we should be taking possession of it in the next week or so as it has also flew the coup and is being driven to the dealership as of this reply. It’s a small Class A RUV a Thor Axis. It just might be a fine MH to learn on and maybe one day a bit of full timing or at least 6 months. So the adventure will start shortly fro the Bride and I and our Certified Therapy Dog Han who is a 118 lb Bernese Mountain Dog who thinks he is attached to the brides heels and her shadow!
    So as a resource to us we will be standing by for another RVGeeks CLIP and who knows maybe one day we will meet and you can say..why did you that ? Here is a better way >>>Newbie Geez they need all the help we can give them..were we like that years ago? Ha! Also congrats of 15 years and let’s hope you guys will give each other and we subscribers at least another 15 years of help and do it in a happy and healthy
    way! You guys rock the trimester scale by me!
    < FISH < the K9Piper

    1. Post
    1. Post

      Thanks, Allan. Glad you liked it. We thought that adding in the steps we took to diagnose the problem would be helpful… glad you agree! ;) Plus, the repair was so easy that the video would have flashed by in a blink if we hadn’t! LOL! This is the first time we’ve ever had a thermostat fail, so we’re not sure if the symptoms might be different for other people (like not heating at all), but this was our experience. So we hope it helps!

    1. Post
    1. Post
    1. Post

We'd Love To Hear From You... Leave A Comment!

This site uses Akismet to reduce spam. Learn how your comment data is processed.