Adjustable thermostat for water heater

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   This mod is probably more for dry camping/boondocking than for those who camp with full hookups.
The non adjustable 130 F temp setting on our water heaters is just too high IMHO. Not only can you burn yourself but its a waste of propane and more importantly a waste of precious water while you spend time adjusting the water temp. 

Much better if you could just turn on the hot water and have it come out at the temp you want it. 
How to accomplish this? Easy, just add an a adjustable thermostat electrically in series with the existing one. It will open and stop calling for heat first, keeping the water heater temp lower than the existing thermostat. Do not attempt unless you have and are comfortable working with a voltmeter and electrical circuits.

I bought a little programmable thermostat board on Amazon for about $10. 

https://www.amazon.com/gp/product/B076Y5BXD9/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

4 wire connections required.  -12 ground, +12 coming from the water heater wall switch. Then cut the wire from the existing thermostat and run it through the switched relay contacts on the thermostat board. All of this is available right at the water heater. Slide the temp sensor under the water heater foam insulation. Program for heating, set the temp differential (hysteresis) to 1 or 2 degrees.  Adjust to your comfort level, done. 

Does not effect water heater operation when using the 120Vac electric heating element, only propane heating. This solution will not work if you wanted to adjust the temp higher than 130F.   We'll see how long the little thermostat board lasts. 

I'll see if I can post a picture or two tomorrow. 

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offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Topic: Adjustable thermostat for water heater Posted: 02 Sep 2018 at 6:50pm
	This mod is probably more for dry camping/boondocking than for those who camp with full hookups. The non adjustable 130 F temp setting on our water heaters is just too high IMHO. Not only can you burn yourself but its a waste of propane and more importantly a waste of precious water while you spend time adjusting the water temp. Much better if you could just turn on the hot water and have it come out at the temp you want it. How to accomplish this? Easy, just add an a adjustable thermostat electrically in series with the existing one. It will open and stop calling for heat first, keeping the water heater temp lower than the existing thermostat. Do not attempt unless you have and are comfortable working with a voltmeter and electrical circuits. I bought a little programmable thermostat board on Amazon for about $10. https://www.amazon.com/gp/product/B076Y5BXD9/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 4 wire connections required. -12 ground, +12 coming from the water heater wall switch. Then cut the wire from the existing thermostat and run it through the switched relay contacts on the thermostat board. All of this is available right at the water heater. Slide the temp sensor under the water heater foam insulation. Program for heating, set the temp differential (hysteresis) to 1 or 2 degrees. Adjust to your comfort level, done. Does not effect water heater operation when using the 120Vac electric heating element, only propane heating. This solution will not work if you wanted to adjust the temp higher than 130F. We'll see how long the little thermostat board lasts. I'll see if I can post a picture or two tomorrow.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 03 Sep 2018 at 10:01am

	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 03 Sep 2018 at 10:18am

	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

furpod Members Profile Send Private Message Find Members Posts Add to Buddy List Moderator Group - pHp Joined: 25 Jul 2011 Location: Central KY Online Status: Offline Posts: 6128	Posted: 03 Sep 2018 at 10:50am
	The biggest problem I see is, the purpose of the high temp is so you can "mix" and get a comfortable temperature for a longer period.. Since 104F to 106F is where most people like their water for showering, it won't take very long at all before you have run down the available hot water, AND diluted/cooled it, with incoming ambient water. Unlike in a house, you only have 6 gallons to deal with vs 40-80 in a home. In my house/camperhold that would make for an unhappy camper pretty quick.

Guests Members Profile Send Private Message Find Members Posts Add to Buddy List Guest Group	Posted: 03 Sep 2018 at 11:34am
	I would be interested in any comments, after using it a while, in regards to quality/longevity and how well it regulates the temperature. In my situation (being single), it may work out well. I use approx. 4 gallons, + or -, per shower so, it would not completely empty the water heater. I speculate that I use more water trying to get the temperature of the flow OK than I do actually showering. If the water doesn't get too cold (during use), it could save both propane and (more important) water from the fresh tank. Maybe it's a question of finding the set point "sweet spot".

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2587	Posted: 03 Sep 2018 at 12:04pm
	6 gallons is a lot of water for a mariner's style shower. The quantity of water in between the sink or shower and the hot water heater in the supply lines is de minimus in the grand scheme of things. Some people like their hot water really hot, others not so much. But the ability to choose the temperature with the device suggested by offgrid is pretty cool. On the other hand it is one more thing that can go wrong. I think I'll continue to rarely ever turn on the hot water except where I have AC available. Most of the time camping in moderately warm temps, the cold water is not so bad for a shower and it makes you wash faster.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 03 Sep 2018 at 1:19pm
	As I said, this mod won't likely be of interest to folks who have water hookups and take long showers or are only doing short stays. In my case, we use hot water once a day for washing dishes and showering. I take a short "navy shower", at the very most I use a gallon. Water on for a few seconds to get wet. A little soap. A little longer to rinse, maybe 30 seconds. DW perhaps uses a bit more. We turn the water heater on in the evening, wash the dishes, then take showers before the water in the lines has a chance to coof off. We can easily go well over a week on our 30 gallon tank, well over two weeks for me if I'm alone. And that's taking daily showers. So fiddling with the water temp uses relatively a lot of water for us. And I hate getting scalded by overly hot water. I put in a tankless water heater at home and have it set up the same way, the hot water comes out at the exact temperature we want, no fiddling with the cold to cool it off. Love it. i did find when testing the new thermostat that I had to leave the outside shower on for what seemed to me a really long time (minutes) before I noticed any water temp drop off. So I don't think having to readjust the water temp as we consume the hot water in the tank is any kind of a problem for us. I'll report back how long the little thermostat board lasts but the way its wired it would take less than a minute to revert back to the standard system if there is a failure. Just disconnect two wires and wire nut them together.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2587	Posted: 03 Sep 2018 at 6:08pm
	Dang, offgrid, your suggestions keep me thinking of the next step. Small tankless water heaters take up a lot less space than the typical RV water heater. Why not just just put one in the trailer and be done with it. Imagine, perfect hot water all the time and you'd recoup about half the space occupied by the storage tank. And, of course, ask, and you'll find it on Amazon: https://www.amazon.com/Camplux-Outdoor-Portable-Propane-Tankless/dp/B01CJPU6JI/ref=sr_1_3?ie=UTF8&qid=1536015876&sr=8-3&keywords=tankless+water+heater+propane&dpID=41VVDcC0oML&preST=_SY300_QL70_&dpSrc=srch On the other hand, I had a tankless water heater about 16 years ago, when I lived in Cali, Colombia. I could never get the water adjusted right; either too hot or too cold. But, I imagine the technology has improved a bit since then.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 03 Sep 2018 at 7:50pm
	My residential tankless electric one works perfectly. I can run it for DW, and then change it by a degree at a time till she says its perfect. Household bliss. I doubt the propane ones are quite that precise though. The problem with the one on Amazon is that I think you'd only be able to use it outdoors in a well ventilated area. Suburban (who makes the rPod water heaters) makes a tankless one that vents through the wall and looks like its a direct replacement. Spendy though. https://www.campingworld.com/suburban-on-demand-water-heater-60k-btu-with-2-stage-mcs?CAWELAID=120030630000026037&gclid=CjwKCAjwt7PcBRBbEiwAfwfVGDc-VBZIQEpLhn5ARWy2k7XFZHDw8mXXkHZP3oWgoUD3Ie2wl62zOhoCPPUQAvD_BwE
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

texman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24 Jul 2014 Location: TeXas Online Status: Offline Posts: 446	Posted: 22 Jan 2019 at 7:19pm
	Good write up. Thanks for posting.
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