RV water heaters fall into several groupings. There are propane only units, propane/electric units and diesel/electric units. The diesel/electric units today are mainly from a company called Aquahot. The other water heaters are sub-divided into tank-less and tank water heaters. Tank-less water heaters are fairly new to the RV world and are made primarily by Girard and Precision Temp. The most common water heater in recreational vehicles are the tank water heaters and come in 6 or 10 gal capacity. Lower end units will be propane heat only and then the most common today is the propane/electric water heaters.
When it come to maintenance these articles will deal with what I call the user maintenance. That is maintenance that does not require special tools or equipment to perform and is listed as user maintenance in the manuals that come from the manufacturers. This set of articles will be broken down based on the types of water heaters (Tank, Tank-less and AquaHot). As with any maintenance, please review the requirements in the owners manual or contact the manufacturer.
Since the most common water heater used on RVs is the tank type, that will be the first one we will tackle. First thing first is safety. Prior to performing any maintenance of the water heater, turn it off and let the water cool before starting. A good time to perform this maintenance is prior to the first trip of the year or when you de-winterize the unit. To perform the maintenance you will need a vacuum cleaner, hand tools, water hose with a sprayer attachment that will fit into the water tank. If your water heater is a Suburban model you may also need an Anode Rod, Atwood water heaters do not need the Anode Rod.
For the maintenance, start by vacuuming out the bugs and dirt. Using the vacuum nozzle, clean out the burn tube. Look for any areas of soot and clean them up as well. Soot is an indication of incomplete burning normally caused by bugs in the burn tube. Once the cleaning is done, put away the vacuum cleaner. Examine the bug screen on the water heater door. If you don’t have one, get one from the RV center near you. You will need to know the type and model which should be on a sticker in the water heater area. Now for the fun stuff. Near the top of the water heater is a relief valve. Open the valve! It will release the pressure built up in the water heater and make the next step easier. This also test the relief valve to make sure it opens. Water may come out of the valve if the tank is over full, which is why you want the water cool before performing this task.
Now to clean out the water tank. For this you will be removing either the Anode Rod or a plug at the bottom of the water heater. Guess I should tell you that there is water behind this rod or plug and when it comes out so will the water. So make sure nothing electrical is in the way and stand to the side if you didn’t wait for the water to cool so you don’t get burned. Once the water has drained out, you will need to flush the tank. Using the water hose and a wand nozzle rinse the tank as best you can.
With the Anode Rod out, inspect it to determine if it should be replaced. Anode Rods are sacrificial, the steel tanks in the Suburban units have a tendency to rust due to corrosive chemicals in the water. The Anode rod attracts those chemicals and sacrifices itself instead of the water tank. You should replace the rod when it is half gone (compare it to a new rod). You do not want to wait for the rod to dissolve completely before replacing it. You could be damaging the tank in the mean time. Atwood heaters are made of aluminum and do not suffer the same fate.
Once the tank is flushed, replace the rod or plug, leave the relief valve open and turn on the cold water. Close the relief valve when water comes out as the tank fills. Test the heater. Turn on the propane tank, set the heater to propane mode and make sure the heater works. Once that is done you can set the heater to your normal operating mode.
Next week I will talk about the tank-less water heater maintenance.