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Camper Mod Contest Entries

Water Heater Time Delay Upgrade

Welcome to the fifth entry in August’s Medium Mod Contest.  One Medium Mod will be published in every Email Alert in August.  At the end of the month, we’ll hold a reader vote to determine August’s winner.  Click here for information about the 2020 Mod Contest, including how to enter.

Water heater time delay for RVs

Ray Fair, Hopkinton, Massachusetts
Water Heater Time Delay
2017 Silverado 3500
2015 Eagle Cap 850

After the coffee pot is started in the morning the propane water heater is turned on. Unfortunately, sometimes we get sidetracked, or something is in front of the lighted switch and the water heater doesn’t get turned off.

Hours later we will hear the water heater turning on. There have been times when we hear the familiar sound of the water heater starting up long after we’ve gone to bed. Considering we are either boondocking or at a state park 80-percent of the time, the wasted LP adds up.

A fellow truck camper friend suggested that we use the timer on our smartphone to remind us to turn off the heater after a period of time. Good suggestion, however, I am always looking for something a little more. Another truck camper suggested a time delay relay to control the water heater. He then went beyond the call of duty to suggest exactly which relay to use. Bingo!

Single Way Relay Module Delay Power Off Trigger Delay Cycle Timing Circuit Switch

I purchased a Single Way Relay Module Delay Power-off Trigger Delay Cycle Timing Circuit Switch by Drok on Amazon for $9.

water heater diagram for relay circuit board

It sounds like a mouthful, but it’s a relay mounted on a PC board with an adjustable digital timer that turns an electrical circuit on or off.

Water Heater Relay Circuit Board

Next, I needed a location to mount the board. I wanted the board to be out-of-sight, yet if needed, accessible to change the relay timer delay setting. The space behind the wall where the water heater switch is located was a good location. The 12-volts of power needed for the relay was within this space. To gain access to the space, for the time being, the stereo was removed.

Water Heater Relay Mod 2

I located and cut the wire that was feeding the water heater and attached it to the + (positive) side of the trigger terminal on the relay board. Why? I wanted the heater switch to trigger/start the timer on the PC board.

Water heater time delay modificaiton for truck campers

Then, I attached a jumper wire from the same + (positive) terminal to the Comm terminal on the other end of the PC board. After that, I attached the other end of the wire going to the heater to the NO (normally open) terminal on the PC board. The timer was adjusted to 12-minutes.

Turning on the water heater switch applies power to trigger the start of the digital timer. The timer on the relay is now controlling the water heater and the lighted wall switch can be turned off.

After 12-minutes, the circuit opens, and the heater is turned off. That is enough time for the 6-gallons of water in the water heater to heat up. If we require a longer or shorter time to bring the water to the desired temperature, the timer delay time could be changed accordingly.

Should additional hot water be needed during the day, simply turn the water heater switch on and the sequence starts again.

This mod has been great. The water heater is no longer running unattended and wasting LP. The bottom line is that I am saving propane which equals saving money.

It took me one hour to complete this modification and cost me $9.  In my opinion, the skill level of this modification is medium.

Disclaimer: The modifications above are submitted by Truck Camper Magazine readers. It is your responsibility to make sure that any do-it-yourself modification project you undertake is safe, effective, and legal for your situation.

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If you’d like to enter a modification you’ve done on your truck camper, click here. You can enter as many mods as you want, at any time.  Good luck mod makers!

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