Water Heater started leaking!!

I noticed a small water trail under the water heater cover.

Not good!
The rust trail leads to the tank area. This is really NOT GOOD!
There several reasons why water would be running under the cover (over pressure valve leaking is quite likely the culprit), but only one reason (That I could think of) why water would be coming from the burner  area, the tank itself is leaking!

I did some research and we have a Suburban SW12DE. It’s a 12 gallon water heater with direct ignition that runs off of propane, electric, or both.  I also learned that other RV water heater manufacturers (Atwood for example) have a different footprint and are not plug and play compared to replacing with the exact same unit. Also, since our cover has custom paint with three colors this would make replacing it for a different vent configuration expensive.

When discussing the issue with our friend, Lee, he mentioned that since the heater is relatively new, maybe we could just replace the tank.  Great idea, only the Surburban models do not have serviceable tanks (although, Atwood models do). Major Bunmer!  So, it looks like a direct model replacement is the way to go.

I have always  had very good luck purchasing parts at www.pplmotorhomes.com.   They are cheaper than Amazon and have free shipping.   I ordered on September 16th and received it on the 18th!  Only 50hrs from order to the door step via UPS!

The water heater on our Class C Motorhome lasted 15 years. According to the manufacturer date this one was a little over 4 years old!    A couple different factors may explain this. First we have been fulltimers for over 3 years now. Many more heating cycles than our Class C that sat it storage 300+ days a year. Also, I replaced the anode rod  about 18 months ago (original lasted over 2 years). I was surprised to see it was totally gone. This may have contributed to the water heaters demise.

Nothing left!
This is what it looks like when new!
I was intending on replacing it while we were here. No need now!

Everything considered, I believe it was likely a manufacturers defect that caused the premature failure. Here is a picture inside the burner tube.

Looks like a weld may have failed!

So here it his step by step pictorial on how I replaced the water heater.

First, make sure all the power (both A/C and D/C) as well as the propane are turned off.  Find the A/C breaker for the water heater and turn off.

Next turn on a hot water supply line and run until the water is warm. You don’t want to get burnt when draining the tank.

Now you can turn off the water supply. You can do this by shutting off the main supply or by simply opening the water heater bypass valve if your unit is equipped with one. This will allow you to have cold water supply to your rig while your replacing the heater.

Now that we made it safe we can begin to remove the old unit.

Next we need to drain the heater by removing the plug/anode rod. I put some buckets under the rig to catch the water so I don’t have to stand in a mud puddle!

Next remove the service cover and set aside.


Our water heater cover came with a plastic retaining clip. They are known to become brittle as the suns UV rays weaken them over time.  It would cost several hundred dollars to replace our custom painted cover if the plastic clip broke and the cover flew off when we were traveling. I replaced it with a metal clip.  Best money I spent on the rig.  Click link to purchase.

Next carefully cut the silicone caulk around the trim. Use an angle that allows the blade to ride under the trim if possible.

Now you can remove the 4 screws that hold the trim to the heater.

Now you can gently pry the trim off. You will likely encounter some butyl sealant that will take constant gentle pressure to remove trim.

You can see the butyl tape adhered to the rear of the trim. I was lucky it all stuck to the trim making it easier to remove.
I also removed 2 screws that attached the heater to the wall.

Next you can disconnect the gas line. Be sure to support the burner side with another wrench or plyers if the flare nut doesn’t loosen right away. You may break the aluminum casting of the burner assembly if your not careful.

Also remove the rubber grommet around the housing to allow the gas line to pass through.

Now you can grab the heater and start to wiggle it out. If you feel some resistance STOP!  The water or electrical connections may not be designed to allow removal without first disconnecting them from the rear. (I replaced the water heater in our Class C Motorhome without having to get behind the it).  This is as far as the heater came out until I felt like something was holding it back.

The only way to gain access behind the heater is to take down our basement wall!  Another Major Bummer!

Basement is full!
After removing most of our stuff it looks much bigger!

After you remove all the screws that hold the walls together they should come out.  I also disconnected the 120V, 12V and antenna receptacles so I could have better access and totally remove them from the basement. (Turn off the appropriate breaker before removing outlets).

Doesn’t look as pretty as the inside of the rig!
You can see that the water lines were preventing the removal.

Place a towel under the fittings to collect the water and disconnect the water lines.

Look around to see what else needs to be removed. I found that the control board was screwed down to the base.

Now pull the heater out until you get access to the electric junction box.

Remove cover and the wire nuts. They may also have electrical tape on them. I always check again with a meter before I put my hands on any bare wire.

Continue to slide the heater out making sure none of the wires are interfering.

Also needed to remove the red tape and wire nits from the control board.

I got out the shop vac and cleaned up some of the debris left over from the factory. I removed what I could reach when our solar was installed but I have much better access now that the heater is removed.

Installation is pretty much the same steps in reverse. I lifted and wedged the heater into the opening so I could make the electrical connection s.

First the A/C power.

I put electrical tape on the wire nuts for extra protection.
Then the D/C power for the control board.

Just 3 D/C wires to connect.
Now you can push it all the way in to make your propane connection. It can be hard to grab the line so I used a pair of needle nose plyers with tape on the ends to grab it.

I used tape so I didn’t scratch the flare fitting. A scratch on the flare may leak propane!
Now we can attach the propane line and protective rubber grommet.

I then reattached the control board to the base.

Now for the water lines. When I squeezed myself in the basement I realized I made a mistake!  Evidently the new heater doesn’t have new brass fittings on the rear. I have to reuse the old ones. They would have been easier to install while the heater was on the picnic table!  Minor bummer!

The brass fittings on the old heater need to be installed on the new one.
The cold water inlet is actually a check valve preventing water from back flowing.

I removed the old teflon tape and applied 5 new wraps on each fitting and installed. These fitting should be torqued down pretty tight.

Be sure to apply tape clockwise on the fitting. Also take note there is a rubber seal on the other end of the fitting. This will help prevent the waterlines from leaking.
Next a reattached the water lines. These fittings should be hand tight or just a tad tighter depending on your grip. If you overtighen it with a wrench or plyers you may damage the rubber seal or deform the plastic fitting to the point where it will leak. If this happens you may have to start over with a new fitting.

Time to fill the heater with water and check for leaks.   After I purged all the air out of the system I verified there are NO LEAKS. AWESOME!!  Next I turned on the power and the propane and turned the unit on. It fired right up!

Nice flame.
You will probably smell something burning for a couple of mins. This is the oil left over on the inside burning off.

With the electric and propane both on it took 33 mins for the unit to come up to temperature shut off. I ran some hot water to heat up the water lines and checked for leaks again and found none!

Time to install the outside trim and put the basement walls back where they belong. First I removed all the silicone from the trim ring and wall of the rig. Be VERY CAREFUL not to scratch the painted surfaces.

This is time consuming but important. Next place the trim on and tap around the outside until it is seated flush against the wall. Now install the 4 screws and tighten until they are snug. Don’t get carried away and bend the trim. Next install the 2 side screws that attach the unit to the wall. I used a spring loaded punch and drilled a pilot hole to make it easier.

Now I cleaned the wall and trim surfaces with alcohol so the silicone would probably adhere.

Note:  I use Isopropyl Alcohol to sanitize water fittings on the camper and on the campground water spigots. I used to use bleach but the overspray is NOT friendly to your clothes. Ask me how I know!

I applied a thin bead using a caulking gun. The better you are at doing this the less you will have to clean up.

Use your finger to smooth and push into any small gaps between the trim and wall. They should be very small.

Put on cover and stick it with a fork!


Here are the tools I used.

Pretty basic tools with the exception of the large socket to remove the anode plug. Ours was 1 1/16″, I used a 27mm 6pt socket that fit well.

Next I harvested spare parts from the old heater. Ever since I was a kid I always enjoyed taking things apart. It helped me understand how they work.

Was able to salvage the complete burner assembly, wiring harness, control board, and thermostats. Didn’t have a large enough socket to remove electrical heating element. I also left the over pressure valve behind as they never leak (unless you test it!)

Packed up in a freezer bag. Marked the bag with what’s inside. (You don’t think you’ll forget what it is, but I know better than to rely on my memory)!

Added to the shoe box with the spare parts for our A/C and furnace. I keep it over our generator prep box in our forward basement.

I also mark when I do things with a marker for easy reference.

Well that it. The job took longer than expected due to needing to access the rear of the heater and having to empty the basement and take down the basement walls.

Easy enough for a DIYer to tackle if they have basic knowledge of electrical and plumbing systems.  Said another way:   If you have the knowledge and confidence to replace a kitchen faucet, a 120 Volt outlet, and a burner on your grill or kitchen stove you should be able to do this.

As with any project that involves propane and/or electricity.


I’m not sure how much money I saved by doing it myself (around $200?), but I can rest easy as I know it has been done correctly.

Thanks for reading!

If you enjoyed this post and would like to receive an email notification when we post again, please enter your email address at the bottom.

Also please leave a comment!  We would love to hear from you!!

36 thoughts on “Water Heater started leaking!!

  1. Excellent post, it doesn’t look easy, but doable. Yeah, your anode rod could have been a contributing factor, I change mine every year.

    1. My first rod lasted over two years. This one totally gone in 18 months. I am going to start changing it annually like you. Cheap insurance!

  2. Good job as usual Bill. You are a jack of all trades. It looked like a lot of time and a lot of work. Enjoy your weekend.

    1. Thanks Jim. Yes, that would be my guess also. Suburban water heater also have porcelain liners. That should arrest any rusting until it gets a crack. Hoping my premature failure was just an anomaly.

  3. That looks like it should have been a lot easier, who designed that installation – not the repairman! Well done Bill, your skills and abilities are amazing.

    1. Thanks Jeff! The job became more complicated and long when I found out that it simply would not slide out the front. My basement was due for cleaning anyway!

  4. My water same model had a weld fail on it too after 6 years. I have a question for you..did you ever have and back pressure in your system? Like when the water just is heating up the water it is hard to flush the toilet or a gush of pressure coming out of the faucet when you just open it? After replacing the hot water heater I still have the back pressure but now if it is alot the pressure relief lets it go. On the old one that never happened.

    1. I never had that issue.
      I would suspect you may have air in you hot water system. When the pocket of air heats up it may create a pressure bubble that quickly releases when a faucet is opened.

  5. Another great job done by Bill 🙂 He is the man 🙂
    Great post Kelly nice helpful read 🙂
    Also I like that in with the tools there is a beer,
    but I think it would have been at least a two beer job 🙂

    1. Thanks Rick! Actually Bill wrote this whole post all by himself! And – he was wondering who might notice the beer! He wants me to tell you it’s a double 24oz can! So – yes it was a 2 beer job!

      1. Tell that he is not only the man when it comes to fixing thing, but he does a great job on posts too 😎

    1. Thanks Steve! It’s one of our ways to pay it forward as so many have helped us in this lifestyle!

  6. Bill,

    Great job! Full timing sure does increase or PM frequency. Thank you for posting this article. It was very detailed and easy to follow. I have the same water heater. A couple questions for you. Do you use a water softener? Did you consider changing to a Truma Aquago unit?


    1. We do not have a water softener. That would solve some issues. I did look at other options including the on demand types. One of the main reasons I went with a direct replacement is our water heater cover has custom paint with three colors. Since the others had a different grill design that would mean I would have to custom paint the new grill cover.

  7. Excellent article Bill and Kelly. Great repair job with easy-to-follow DIY instructions and pics. Great job you are the man Billl!

  8. I am all for DIY repair and the time and effort you took to share your water heater replacement process is greatly appreciated. I hope I won’t have to do the job in the future but if the time comes then your info will significantly improve my confidence to take on the chore. Thanks again.

  9. I have the same model hot water heater in my 2012 Bighorn. It leaked last year when we were in Big Bend State Park. The unit was 6 years old and it leaked in the same exact place as yours. The extended warranty company wouldn’t pay to have it replaced because they said it was caused by rust or corrosion! Well yeah, where the weld failed and it started leaking there was rust, duh! Great tutorial, perfect explanation. Thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *