Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM. Today I discuss water heater elements.
I found this post on another RV group page and thought it was an important reminder….
I went to winterize the trailer (sadness) and decided to get a jump on draining the hot water tank before I even hooked the power. Well, you guessed it. I didn’t follow my normal winterizing routine and simply flip the little on/off switch to off in the hot water tank. The switch was left on in the trailer, which I usually always turn off at the end of any trip. Hooked up power and realized later the switch was on in the trailer.
So I’ve searched for the correct heater element and can’t find the exact part number for my model # SW12DEL water heater. I found this one on Amazon. Are the heating elements universal? Seems like a good deal. I will certainly need the removal tool. —Rob B.
Dear Rob B. (and all my readers),
As you just found out, even a few seconds of dry firing an electric water heater can burn out your water heater element. This is not something you normally have to worry about for your bricks-and-sticks house because you don’t normally drain your water heater. So, I’m sure you’re going to remember this lesson come springtime when you get ready for the season.
Checking the details…
First, is this a 120-volt element? Be aware that the vast majority of water heater elements are built for 240-volt power, and your RV needs a 120-volt element. If you accidentally swap in a 240-volt element, nothing bad will happen. But the wattage will be reduced to 25% of rating. So, instead of 1440 watts of heat it would only provide 360 watts. That’s definitely NOT hot water. So, YES, this element has the correct voltage.
Second, does the wattage match up? While some home water heater elements are rated up up to 3,500 watts (at 240 volts), the typical RV electric water heater element is rated for 1,400 to 1,500 watts. This element is rated for 1,440 watts. So, YES, that seems correct.
Third, will this water heater element physically fit? It appears that your burned element is a single long loop instead of a bent loop like some water heaters use. And the mounting flange thread size should all be the same for a modern water heater. And I like the wrench that will also allow you to pull and replace your anode, so that’s a good thing as well. So, YES, I think this kit looks like a great deal.
Always to sure to turn off the power switch on your RV water heater before doing any sort of service, including draining the tank for winterizing it. And double-check this in the spring before you turn on the power to prep for your first trip of the season.
Also, I think it’s probably a good idea to get a backup water heater element and wrench for your RV and carry them with you on the road. Don’t expect to find what you need while you’re out camping, so be sure you carry the essential repair items that you and your family need to be Happy Campers.
OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
And you don’t want to miss Mike’s webcasts on his YouTube channel.
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