Since I had my rig home from storage for a couple of days to do my camera mod, I decided to do a couple more useful ones to help us boondock longer without having to break camp.
Based on a hot water recirculating system I installed in my previous motorhome, and on similar ones posted in this forum by Robbbyr and others, I installed a system to purge ambient temperature water from the hot water lines and send it back to the fresh water tank. My kitchen sink is the furthest point from the hot water heater. It took 50 seconds for hot water to reach the kitchen sink. I measured the amount of water... in 50 seconds 134 ounces of water passed thru the kitchen faucet (faucet set to hot water only) during that time. A similar test at the shower faucet measured about half that amount, 65 ounces. Since we are a family of five, nightly we would waste 2-3 gallons waiting for hot water to arrive at the shower head. Doing dishes three times a day wasted another 3 gallons waiting for hot water to reach the kitchen sink. Over six gallons wasted daily waiting for hot water. This wasted fresh water also prematurely fills up the grey tank, another enemy of boondocking. I added a 12 volt 1/2” valve under the kitchen sink tee’d into the faucet’s hot water line. I ran the output from the valve thru a 1/2” line back to the fresh water tank. I reassigned one of the three fresh water tank’s overflow connections to terminate the recirculation return line into the fresh water tank. I controlled the 12 volt valve under the kitchen sink with an illuminated push button, and an adjustable time delay relay. Pushing the button energizes the relay and the push button’s light for 50 seconds. I mounted the relay under the kitchen sink, and mounted the push button in the cabinet wall between the kitchen wall and the cooktop just under the countertop. Installation took a day. Parts cost about $100.
Also I modified the fresh water over flow tubes to prevent the syphoning that sometimes depletes your fresh water supply while driving. I modeled an air-brake manifold after the one Robbbyr designed and has shared in this forum. Thank your Robert!
I also added a quick disconnect hose to the Seneca’s low pressure propane line to fuel our Mr Heater Big Buddy catalytic heater to allow us to gain some heat in our rig without having the furnace fan run down our house battery bank. I tee’d into the propane line that feeds the propane cooktop. I also added an extra CO detector in the bunk bed and master bedroom area for safety and piece of mind.
These mods will enable us to boondock longer before having to break camp for refilling our fresh water tank, and dumping the grey tank. And also be a little more comfortable while cold weather camping. These are really good things for us.
Thanks to all on this forum your inspiration and help!
Looks good, two mods that I want to do but the DW is fighting me . She doesn’t like the idea of a Big Buddy heater inside no matter what I say.
On the circulation system, she says she doesn’t want to have to remember to cycle it all the time. Been thinking of trying a circulation system using a small pump like in solar water heater setups and use one of the programmable relays that I used in the auto entry door lighting and have it triggered by a thermal sensor, then insulate all the hot water lines. It would take some testing to program cycle time and not sure how much power draw would be but it would be a true instant hot water system. I did just find out about a water pump that doesn’t used much power and is the inverter cooling pump on a Prius.....hum. If it didn’t work out, I could change it to a system like yours.
__________________
Brian & Jeannie
2018.5 Seneca 37RB with to many mods to list
2015 Jeep JKU Rubicon
Looks good, two mods that I want to do but the DW is fighting me . She doesn’t like the idea of a Big Buddy heater inside no matter what I say.
On the circulation system, she says she doesn’t want to have to remember to cycle it all the time. Been thinking of trying a circulation system using a small pump like in solar water heater setups and use one of the programmable relays that I used in the auto entry door lighting and have it triggered by a thermal sensor, then insulate all the hot water lines. It would take some testing to program cycle time and not sure how much power draw would be but it would be a true instant hot water system. I did just find out about a water pump that doesn’t used much power and is the inverter cooling pump on a Prius.....hum. If it didn’t work out, I could change it to a system like yours.
I chose the Mr Heater Big Buddy model because it has a quick disconnect connector for low pressure propane. Working with low pressure makes me feel a bit more comfortable. But I still keep an extra CO detector and fire extinguisher nearby, and I closely monitor it when we use it.
Your concept for true instant hot water is a bit more ambitious than the system I installed, but creating the design and seeing it thru implementation is a big part of the fun! We don’t find the push button approach intrusive or inconvenient. Finding a place for the push button that is convenient but yet doesn’t invite too much interest for our young twins to play with is a challenge tho. 😁
This is a great project and the returns are well worth the efforts.
I returned the water to the outlet line of the fresh tank. This way when I trigger the pump it makes a recirculation loop. During cold weather I have triggered it during the night and it keeps the lines warm. I am thinking about getting an additional on/off timer that will simply cycle 1 minute every x minutes. That will keep the lines warm and provide instant hot water. Adding some pipe insulation will also help.
One additional thing I am looking at doing is changing the feed line to water heater. Currently the lines run through the basement to the rear compartment much of which is not heated. I want to reroute the lines through my bedroom cabinets. This will reduce un heated piping by 90%. There will just be 2 ft behind the heater that will be in untreated space vs about 20'. This will also allow me to seal some openings between some of the bays. I already have the washer supply lines in the cabinet so it really is just a matter of dropping these down into the area behind the heater.
James AO, wondering if you would share which timed relay you have used for your recirculating system?
I have done the recirculating mod however was having problems trying to adjust the run time on the Beuler BU508TD relay that I was using. I ended up breaking off the tiny adjustment screw, so last few trips I installed a standard relay and had to hold the momentary switch for the 40-50 seconds.
This is a great project and the returns are well worth the efforts.
I returned the water to the outlet line of the fresh tank. This way when I trigger the pump it makes a recirculation loop. During cold weather I have triggered it during the night and it keeps the lines warm. I am thinking about getting an additional on/off timer that will simply cycle 1 minute every x minutes. That will keep the lines warm and provide instant hot water. Adding some pipe insulation will also help.
One additional thing I am looking at doing is changing the feed line to water heater. Currently the lines run through the basement to the rear compartment much of which is not heated. I want to reroute the lines through my bedroom cabinets. This will reduce un heated piping by 90%. There will just be 2 ft behind the heater that will be in untreated space vs about 20'. This will also allow me to seal some openings between some of the bays. I already have the washer supply lines in the cabinet so it really is just a matter of dropping these down into the area behind the heater.
.
Nice approach and ideas. In your proposed change would you add two solenoids, controls, and circulation pumps, one for the hot water line, and another for the cold?
So I'm assuming you guys have seen the RV Aqua View recirculating system. It is pretty slick and has a blue tube that changes color when hot water is available. Great for boon docking. Not needed in my rig since the water heater is 4 feet from the shower. But I can see the benefit on most rigs.
James AO, wondering if you would share which timed relay you have used for your recirculating system?
I have done the recirculating mod however was having problems trying to adjust the run time on the Beuler BU508TD relay that I was using. I ended up breaking off the tiny adjustment screw, so last few trips I installed a standard relay and had to hold the momentary switch for the 40-50 seconds.
Thanks
Bruce
I used this adjustable time delay relay form Amazon:
I bought the double pole version, but you really only need the single pole version to do the job. I think the double pole version was actually slightly cheaper when I bought it a few days ago, and I figured who knows... maybe someday I will have a use for the second set of contacts. You adjust the time delay with the two red dials on the front of the relay. The top dial is for the broad range of time, and the second dial is for percentage you want of the broad range. I wanted 50 seconds after measuring how long it took to get hot water to my kitchen faucet. So I set the top dial to the 1 minute setting. I set the second dial to 83% to achieve a 50 second second delay. The relay easily clip mounts on a standard inexpensive rail from Amazon. I epoxyed the rail to the inside wall of the kitchen sink cabinet. It is easy to get to, and easy to adjust the timer.
I bought the double pole version, but you really only need the single pole version to do the job. I think the double pole version was actually slightly cheaper when I bought it a few days ago, and I figured who knows... maybe someday I will have a use for the second set of contacts. You adjust the time delay with the two red dials on the front of the relay. The top dial is for the broad range of time, and the second dial is for percentage you want of the broad range. I wanted 50 seconds after measuring how long it took to get hot water to my kitchen faucet. So I set the top dial to the 1 minute setting. I set the second dial to 83% to achieve a 50 second second delay. The relay easily clip mounts on a standard inexpensive rail from Amazon. I epoxyed the rail to the inside wall of the kitchen sink cabinet. It is easy to get to, and easy to adjust the timer.
So I'm assuming you guys have seen the RV Aqua View recirculating system. It is pretty slick and has a blue tube that changes color when hot water is available. Great for boon docking. Not needed in my rig since the water heater is 4 feet from the shower. But I can see the benefit on most rigs.
I am familiar with RV Aqua View. I considered it when I added a recirc system to my last motorhome. I didn't like the appearance of the color changing pipe and valve that has to be installed inside the shower stall, so I opted to create my own approach. I enjoy the challenge of finding alternatives. Their product does the same thing my approach does, but slightly less elegantly in my opinion. Some may find their approach simpler to install, personally I thought it wasn't. Either way, the water saving results are great!
This is the relay I have been using for projects, its quite a little unit with 18 different adjustable programs. In a circulation setup you could just have a momentary switch to trigger the system and it would run for X amount of time that you program or on/off switch to trigger and it could run for X amount of time, pause for x amount of time and then cycle again unlimited amounts of cycles until turned off......so many ways to use this little thing. The manual that comes with it isnt very good but I found the full manual and have attached it here. There are even enclosures for it on Ebay.
__________________
Brian & Jeannie
2018.5 Seneca 37RB with to many mods to list
2015 Jeep JKU Rubicon
This is the relay I have been using for projects, its quite a little unit with 18 different adjustable programs. In a circulation setup you could just have a momentary switch to trigger the system and it would run for X amount of time that you program or on/off switch to trigger and it could run for X amount of time, pause for x amount of time and then cycle again unlimited amounts of cycles until turned off......so many ways to use this little thing. The manual that comes with it isnt very good but I found the full manual and have attached it here. There are even enclosures for it on Ebay.
That’s a great, versatile timer, FRM01. I used it in the hot water recirc project on my previous motorhome. You are right, figuring out how to program it can be a bit challenging, but with a bit a patience you can make it do pretty much anything you want. Great choice for projects.
This is a great project and the returns are well worth the efforts.
I returned the water to the outlet line of the fresh tank. This way when I trigger the pump it makes a recirculation loop. During cold weather I have triggered it during the night and it keeps the lines warm. I am thinking about getting an additional on/off timer that will simply cycle 1 minute every x minutes. That will keep the lines warm and provide instant hot water. Adding some pipe insulation will also help.
One additional thing I am looking at doing is changing the feed line to water heater. Currently the lines run through the basement to the rear compartment much of which is not heated. I want to reroute the lines through my bedroom cabinets. This will reduce un heated piping by 90%. There will just be 2 ft behind the heater that will be in untreated space vs about 20'. This will also allow me to seal some openings between some of the bays. I already have the washer supply lines in the cabinet so it really is just a matter of dropping these down into the area behind the heater.
.
Following up on your idea to use a timer to turn on the hot water recirc system for 1 min every X minutes I just added a second din rail mounted relay beside the first one I described in my OP. I turn the new relay on with a din mounted on/off switch. The second time delay relay is an asymmetrical dual timer relay. You can easily set it from its front dials to alternate between two time cycles until it’s trigger is removed. currently I have set it for 3 mins on followed by 57 mins off. When the night temps are forecasted to dip down to freezing I turn the timer on. I turn it off in the morning. While on it will turn on my hot water recirc system for 3 minutes every hour. This will periodically keep hot water flowing in the lines and add hot water to the fresh water tank keeping its temp higher. The output contacts of the new timer relay are connected in parallel with the push button that operates my orig hot water recirc system. That way the original system can continue to work as designed. I can easily alter the X minutes on followed by Y minutes off on the front on the new relay.
Following up on your idea to use a timer to turn on the hot water recirc system for 1 min every X minutes I just added a second din rail mounted relay beside the first one I described in my OP. I turn the new relay on with a din mounted on/off switch. The second time delay relay is an asymmetrical dual timer relay. You can easily set it from its front dials to alternate between two time cycles until it’s trigger is removed. currently I have set it for 3 mins on followed by 57 mins off. When the night temps are forecasted to dip down to freezing I turn the timer on. I turn it off in the morning. While on it will turn on my hot water recirc system for 3 minutes every hour. This will periodically keep hot water flowing in the lines and add hot water to the fresh water tank keeping its temp higher. The output contacts of the new timer relay are connected in parallel with the push button that operates my orig hot water recirc system. That way the original system can continue to work as designed. I can easily alter the X minutes on followed by Y minutes off on the front on the new relay.
I like it the operational layout and will grab a few of those timers. Much better looking timers then what I currently have.
I started to my repipe project last saturday but had to stop due to lack of time and the amount of effort required to remove the heater. The guy who upgraded the truma caulked the unit in place and with the temperture in the 30s it was going to take too long to get the unit out. I will have wait till we return from our trip to North Carolina this week.
I like it the operational layout and will grab a few of those timers. Much better looking timers then what I currently have.
I started to my repipe project last saturday but had to stop due to lack of time and the amount of effort required to remove the heater. The guy who upgraded the truma caulked the unit in place and with the temperture in the 30s it was going to take too long to get the unit out. I will have wait till we return from our trip to North Carolina this week.
I look forward to hearing how your repipe project goes. Share the details when you are able to get back to it. Safe journeys.
Our Truma water heater starts out life as a basic and we can upgrade to comfort. However, if Truma would allow us to do another upgrade we could get to Comfort Plus which did recirculate the how water through the lines, similarly to houses with a recirculating pump, to make it truly on demand hot water. Perhaps Truma would consider offering this to those of us out of warranty who want to do the setup.
Our Truma water heater starts out life as a basic and we can upgrade to comfort. However, if Truma would allow us to do another upgrade we could get to Comfort Plus which did recirculate the how water through the lines, similarly to houses with a recirculating pump, to make it truly on demand hot water. Perhaps Truma would consider offering this to those of us out of warranty who want to do the setup.
Been working on this but getting stonewalled. If you have upgraded to the Comfort, the only part you need is the the tube above the pump that has the inlet for the circulation return, Part number 28 in the exploded diagram in the manual. I talked with a Truma tech and he said there is no way he can get that part and admitted its ridiculous that he cant. I asked what if I said my unit had frozen and cracked this part and he said they would want your serial number and that would sow it wasnt a Plus. He said that I could try ordering through a Truma distributor or OEM. I have emails into about 5 distributors/dealers but have not heard back. I could try Jayco but doubt I would get anywhere.
__________________
Brian & Jeannie
2018.5 Seneca 37RB with to many mods to list
2015 Jeep JKU Rubicon
Following up on your idea to use a timer to turn on the hot water recirc system for 1 min every X minutes I just added a second din rail mounted relay beside the first one I described in my OP. I turn the new relay on with a din mounted on/off switch. The second time delay relay is an asymmetrical dual timer relay. You can easily set it from its front dials to alternate between two time cycles until it’s trigger is removed. currently I have set it for 3 mins on followed by 57 mins off. When the night temps are forecasted to dip down to freezing I turn the timer on. I turn it off in the morning. While on it will turn on my hot water recirc system for 3 minutes every hour. This will periodically keep hot water flowing in the lines and add hot water to the fresh water tank keeping its temp higher. The output contacts of the new timer relay are connected in parallel with the push button that operates my orig hot water recirc system. That way the original system can continue to work as designed. I can easily alter the X minutes on followed by Y minutes off on the front on the new relay.
The final product. Sorry for the photo rotation, I can’t seem to get around it. You are looking at the right bottom corner of my kitchen sink, and the relays are mounted on the inside wall of the cabinets just beside it.
Been working on this but getting stonewalled. If you have upgraded to the Comfort, the only part you need is the the tube above the pump that has the inlet for the circulation return, Part number 28 in the exploded diagram in the manual. I talked with a Truma tech and he said there is no way he can get that part and admitted its ridiculous that he cant. I asked what if I said my unit had frozen and cracked this part and he said they would want your serial number and that would sow it wasnt a Plus. He said that I could try ordering through a Truma distributor or OEM. I have emails into about 5 distributors/dealers but have not heard back. I could try Jayco but doubt I would get anywhere.
We need to find someone with the plus model and get them to order them for us. When I tried to get it I was told no. If I remember correctly when I looked at it. it really is just a tee and restrictor. When I pull the unit out I will pull it apart and see if I can solder something up.
I am afraid my plumbing skills do not include soldering. Wonder if we can get Mark to pick us up some of the parts we need from the Truma service center in his neck of the woods.
Kills us that they will not allow us to upgrade these units. Comfort plus would totally resolve my issues of water lines freezing up in even the coldest temperatures (WV is not as cold as Illinois).
. She doesn’t like the idea of a Big Buddy heater inside no matter what I say. 
Linear Mode
