Seneca - Conserving water waiting for it to get hot...

[SloPoke]

We have a Seneca 36FK and 98% of our trips are Dry Camping for multiple days. Water is a precious resource that is wasted waiting for the water to get hot in any of the faucets or shower (regardless of the type of Water Heater you have). We even try to capture as much of it as we can for the dog bowls, but it is more than they will drink.

So - decided to rig up a bypass to run the hot water - back to the Fresh Water Tank. Our Kitchen sink is the farthest from the Water Heater, so we put a bypass solenoid valve in the hot water line, and let the running water flow back into our Fresh Supply.

First - routed a half-inch ID poly water tubing from the Fresh Water Tank to the Kitchen Sink area. This took a bit of work opening each of the outside cabinets to access the area where the plumbing and electrical already are routed, and tied the discharge end of our line to one of the vent connections.

Second - Purchased a 12v Brass Solenoid valve with 1/4 inch connections and began to plumb the Tee into the Hot Water line under the sink. For FK owners, the easy way to access this is to remove the outside TV. Six screws holding the bracket and it is out of the way. I mounted the valve on a piece of scrap so that everything would remain secure on rough roads and plumbed the TEE between the Hot Water connection on the sink.

Next - I wired the solenoid valve to a push-button (Normally Open - Momentary Closed) switch and mounted the switch on the cabinet facing right next to the Kitchen Sink. A perfect switch is a everyday doorbell switch at the Home Depot - just pick your decor!. The power came from the Red/White wires that power the outdoor Stereo with a 2A fuse inline.

How it works??? Push the button on the cabinet for about 15-20 seconds (time varies because of the lousy tankless water heater) The Water heater kicks in and you have now run the equivalent of 3/4 of a gallon of water to get Hot Water to the tap (but back into your fresh tank). Let the switch go and use your sink with Hot water right away.

Here are a couple of pictures...

Steve & Stacy
2015 Seneca 36FK (with a 2016 Coach on the chassis)

[SloPoke]

[Grumpy]

Get a patent for the kit.

[mike837go]

Originally Posted by SloPoke

... Water is a precious resource that is wasted waiting for the water to get hot in any of the faucets or shower (regardless of the type of Water Heater you have)....

I had read of a similar system for houses, back before bottled water became a 'thing'.

Those used a solenoid and local pump at the most distant (from the water heater) faucet to circulate the cooled-off water back into the water heater via the already existing cold water line. A push-button at each point of use triggered the system for a fixed period of time.

I do like your system. Just dump the cooled off water back into the fresh water tank. Zero waste. You gotta run the pump to eject the cooled-off water and heat the water that will eventually cool off anyway.

Neat!

[Kave&Lucky]

That's "DAM SKIPPY" right there !!

[Robbbyr]

I hope to do something very similar to my Seneca for the same reason, to conserve water when dry camping. I have a TS, so I am certain the plumbing layout is different. But similar to SloPoke's FK my kitchen sink is also the furthest fixture from the water heater, so that is where I will likely tie in too. I already swapped out my unreliable Girard tankless for a 10-gallon Atwood XT gas/electric water heater, so consistent hot water is always there just waiting. This mod will bring it to the sink, but the shower also benefits since it branches off before the kitchen sink.

One addition I am researching is a timer circuit that will hold the solenoid open for a pre-determined (and hopefully adjustable) period of time. It's not that holding the momentary switch is that difficult, but the DW would better appreciate being able to just press a button and then climb in the shower knowing hot water will be there in 3 seconds instead of 30!

Thanks SloPoke for providing more motivation to get this done!

[SloPoke]

Originally Posted by Robbbyr

One addition I am researching is a timer circuit that will hold the solenoid open for a pre-determined (and hopefully adjustable) period of time. It's not that holding the momentary switch is that difficult, but the DW would better appreciate being able to just press a button and then climb in the shower knowing hot water will be there in 3 seconds instead of 30!

Thanks SloPoke for providing more motivation to get this done!

I am very interested in seeing what you come up with for the timer... for those who still have the original water heater and for those who have upgraded back to a "tank heater" will have a different experience. Tankless timings will likely be a lot longer than those with Tank heaters. And I expect Tankless timings will be subject to the ambient temperatures as well.

I would think that an adjustable(tunable) circuit will be good for the timer, and then all it takes is one push of the button.

[Robbbyr]

You inspired me to research the timer, I found this device which looks like it would work very well. You can even remote-mount the potentiometer (maybe next to the pushbutton?) to alter the delay, perhaps useful if you were cold weather camping.

I-30: Adjustable Timer from 1 Second to 3 Minutes Voltage . 12V. D.C: Cebek

[pawpaw]

Great idea and well done!

[Tedd]

Great idea..... I may need to incorporate this mod in my 32RLDS.

[SmokerBill]

I like it. Maybe it could be upgraded with a microprocessor and a thermocouple. When it senses hot water, the microprocessor changes the valve state. Looks like a fun project to play with.

[mjlaupp]

Originally Posted by SmokerBill

I like it. Maybe it could be upgraded with a microprocessor and a thermocouple. When it senses hot water, the microprocessor changes the valve state. Looks like a fun project to play with.

Has already been produced: Watts 500800 Hot Water Recirculating System with Built-In Timer - Sump Pumps - Amazon.com

[Robbbyr]

Originally Posted by mjlaupp

Has already been produced: Watts 500800 Hot Water Recirculating System with Built-In Timer - Sump Pumps - Amazon.com

I put one of those in my daughter's house and it works very well. Only problem, 110-volt pump may not work too well in RV environment when boondocking. Now if they had a 12-volt pump rated for hot water service.......

[norty1]

When we installed the Tankless wh in our home , this is what we added to prevent wasting running water to get hot water to the taps.

Chilipepper Water Heater Pump and Hot Water On Demand System Pump For Faster Hot Water!

Maybe it could be adapted to a mh, just another idea.

[RobertCowdery]

Did not water recirculation a few years ago with timer and flow/ temperature switch. The timer has a bunch of operating modes that should work. Here is a link but if it doesn't work just search for my posts. The parts and wiring details are there

http://www.jaycoowners.com/forums/f3...tml#post307827

[Mustang65]

I probably would not recommend using the water recirculation idea in a TT as it only has a 5 or 10 gal hot water heater, and unlike the 50+ hot water heater at home the heater would constantly be starting up to re-heat the water and the pump will eat away at your remaining battery Ah.

So here are my 2 designs:
... THE MANUAL WAY is to drill a hole in the top of the sink's counter top, insert a nice FANCY tube (Keep DW happy) that is sticking up... take the kitchen faucet hose, hold it over the decorative tube, turn on the hot water.. the water goes into the tube that has a hose under the sink that drains into the fresh water tank... water is ready to be used again... (use the heat sensors in the finger tips to notify the brain when the heated water has reached the faucet.) GUARANTEED TO WORK

Parts list:
- (1) 3' length of clear 3/4" hose
- (1) Fancy piece of pipe (for above sink)
- (1) 3/4" Tee fitting (splice water input hose (from outside filler) insert Tee and connect hose to fancy piece of pipe on top of the sink

OR... THE ELECTRONIC WAY

the FUN way.. a few more $$$$, some additional time, parts, debugging, testing, head scratching and then something to brag about

Here is the initial schematic to accomplish the same thing as the MANUAL version... Take a look at it... have you been able to figure out how it works?
I will post the instructions once you scratched your head a few times.

Don

PARTS (not all parts (2 electric valves (1) NO and (1) NC) or which thermostat to use in the final selection of parts)

[SloPoke]

UPDATE: We just came back from a week-long trip to Colorado (Country Jam) where we were dry camping from Wednesday - Monday in a hay-field with thousands of other RV's. We got to see really how the Hot Water situation is a better experience with the Girard demand water heater.

We found that if the Girard is allowed to actually heat up and run for 30 seconds before you start to shower.. it does a good job for a hot shower. Stacy and I both took our Military style showers after running hot water thru the lines back to the fresh tank and then starting our shower. Hot water was there right away and it did not cycle hot/cold like it did before. We would feel an occasional warm moment vs Hot when turning the water back on / off, but it was not like before when it was Cold/Hot.

We are now going to keep the Girard water heater...

[BuddyRay]

Looks really interesting but I can't quite figure out the flow. Part of the problem is I don't know how the system was from the factory. It would be great to have a stage by stage description.


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