Dear Dave,
We live in our motorhome full time. Do we need to turn off the gas/electric water heater when we’re not using it if we’re hooked up to shore power? —Larry, 2013 Winnebago Adventurer
Dear Larry,
Depending on the floorplan, your unit most likely has a 10-gallon Atwood water heater that runs on either liquid propane (LP) or 120-volt AC power when plugged into shoreline power or running on the generator. Although this is a much older model, it is very similar and was in a 2003 Winnebago Adventurer.
Connected to shoreline power
When you are connected to shoreline power and have the water heater set to the electric mode, it will run on 120-volt power supplied by the distribution center. You can run it continuously, as there are no moving parts that would be subjected to wear and tear.
However, the unit will “cycle,” meaning the thermostat will sense when the temperature in the tank drops below 120 degrees and activate the heating elements, which will heat the water. This can happen many times depending on the ambient temperature. Even though there are no moving parts, any time an electrical component gets very hot and cools down, there will be some weakening of the components, in my opinion.
I leave water heater off
I personally leave the water heater off, as it typically only takes about 10 minutes for the water to get to temperature and I can wait that long for a shower. This is also a good idea if you are dry camping or boondocking and using the water heater on the LP mode as it will save 12-volt battery power and LP.
Since your water heater is an Atwood, it does not have an anode rod, but rather uses the tank as the sacrificial metal. Some long-term RVers that have Suburban units with an anode rod like to shut the water heater down either on LP or 120-volt power. That is because the constant heating and cooling activates the corrosive elements in hard water and increases the deterioration of the tank. Most of the units in my area are Winnebago and they have used the non-anode Atwood version for years.
You might also enjoy these posts from Dave
- No hot water pressure in back shower; cold is fine. Water heater too far away?
- Twelve Days of Christmas RV Tools—Third day: water heater flush wand
- Bad well water caused algae growth in RV water heater. Can’t get rid of it
- Will I ruin my water heater by running it with no water?
- Best way to clean and sanitize RV fresh water tank
- Your RV’s fresh water system: What you should know
- Where is RV fresh water tank’s low-point drain? I can’t find it
DAVE HAS ANSWERED MORE THAN 1,000 readers’ maintenance and repair questions. Read a directory here. There is so much to learn!
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
HAVE A QUESTION FOR DAVE?
Send your inquiries to him using the form below.
RVDT2838
One other thing to consider is amount of power the element uses.
When the element is on, it is consuming upwards of 1500 watts or 12 amps. If you have a 30 amp shore power, you are limited to what other devices can be used. A coffee maker, microwave space heater or the air conditioner can tax the total power available.
Not a problem if you are only using propane.
Except that you are using up the propane. My old Class Bs with propane tanks needed to be refilled about every week in cold weather (in Virginia, not super cold.)
Thank you for sharing the question and answer, Dave. You are increasing my knowledge of RV operation and maintenance, day by day. Have a great day and safe travels!