Dear Dave,
We have a Suburban 10-gallon gas/electric water heater. We run it with the gas on. Most of the time it will work just fine, but then at least once a day the gas won’t kick in. The reset light will kick on three times and then won’t turn off. It will take 3 or 4 tries to get it to work after that. We’ve had it worked on a couple of times and they say it works fine. Any ideas? Thanks. —Deb, 2023 Newmar Kountry Star
Dear Deb,
Since you are running the unit on liquid propane (LP) instead of 120-volt power, I assume you are dry camping and not connected to a shoreline power. That means you are relying on the house batteries for power and those batteries are running many other things as well.
According to the 2023 Newmar brochure, there are 12 different refrigerator configurations, starting with a Norcold 10 CF standard, and then several Whirlpool options with additional batteries. So, it is difficult to pinpoint which “energy hog” refrigerator you have in the rig.
The additional batteries listed are two 6-volt deep cycle batteries. Therefore, I also assume your rig came standard with 6-volt batteries, and most likely four connected in series and then parallel. It also shows a standard 2000-watt Xantrex inverter, so those batteries are powering quite a few components, I would believe.
Problems at campsite but not dealer
My guess would be the 12-volt supply to the water heater has dropped due to other items starting up or kicking on at a certain time. I call these Gremlins, as they are hard to find and the dealer cannot duplicate the same situations you have at the campsite.
You have this problem while camping and the variables are the ambient temperature and the other appliances that are drawing power. Then when you take it to the dealer and it’s a perfect 70 degrees inside the service shop, they plug into 120-volt power, and the water heater works fine, and every test they run is within standards. Even if they unplug the rig and run just on 12-volt power, everything checks out. However, nothing else is drawing power from the rig and they are not running it for 20 hours until it quits.
What I would suggest is to have a multimeter ready the next time you go “gremlin hunting.” When it stops working, check the voltage at the water heater to verify you have at least 12.6 volts. Then record how long it worked before it quit, what was the ambient temperature outside, and what other appliances were running. If you have the Whirlpool residential refrigerator, those are high-power draws and the hotter the temperature, the more they will drain the batteries.
Also, list all things that were on during the day such as TVs, radios, satellite dish, chargers, and all appliances. And, since you have an onboard generator, start the generator and see if that makes it work, as the generator would provide 120-volt power to your inverter, which is also a charger, and give a constant 13.2 volts, at least.
Leaving the RV water heater on all day
Another question is, are you leaving the water heater on all day? I recommend leaving it shut off when not in use as it will cycle all day long. That is excessive if you only need it a couple times a day. It only takes about 10 minutes to start and get to temperature. Try this and see if it stops the issue, as well.
If you are plugged in to shoreline power and have sufficient 12-volt power to the water heater, try switching to the 120-volt mode and see if that works. If it does, there is something that gets weak with the LP mode, which could be the thermocouple. This is a sensor that indicates there is a flame and tells the module board to keep the gas valve open.
It could also be the temperature or emergency cut off (ECU) switch. You could verify this by switching to 120-volt.
You might also enjoy this from Dave
My RV’s electric water heater trips the main breaker. Why?
Dear Dave,
My electric water heater is causing the trailer to lose power. The LP heater can be on. My question is what would be the top three causes of this? It has been fine until now. Just tripped. I replaced the 30A breaker in the camper thinking that would do it. —Skip, 2022 Grand Design Transcend XPLOR 245RL
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Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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