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Vintage465's avatar
Aug 15, 2021

Hot Water Re-Circulation Pump

I happened to have all the corroplast under belly off of my trailer a while back so I figured it would the right time to make some "inside the belly upgrades!
It takes this much water to get hot water to my shower

So I tapped into the hot side of the shower faucet thru the access.

Then I installed this little food safe, hot water recirculating pump

All completed it looks like this. I did install a check valve in place of the plastic valve you see between the pump and the cold water inlet of the water heater.

There was a switch outside the bathroom that was used to turn on the light in the bathroom. We always turn the light on in the bathroom using the switch on the light, so I re-purposed that switch to turn the re-circulation pump. I turn the pump on for 30 seconds, then turn it off and I have instant hot water at the shower. Pretty snappy since we do mostly boon docking.
  • Pretty "cool". Luckily mine takes very little time to get hot. I'll be first in line to do this on future RVs if necessary.
  • That's a great idea, I might copy it. I realize it's only on for 30 seconds but is the pump fairly noisy? Where did you source the pump and check valve? I tried finding a valve a few years ago and didn't have much luck.
  • opnspaces wrote:
    That's a great idea, I might copy it. I realize it's only on for 30 seconds but is the pump fairly noisy? Where did you source the pump and check valve? I tried finding a valve a few years ago and didn't have much luck.


    The pump just makes a little "whir". I sourced the pump thru Amazon and the sharkbite 1/2" pex check valve thru Ebay. The big deal was really getting the 1/2 pex pipe from the shower faucet to the water heater. It is across the hallway and having the belly down made this a do it now while the opportunity is ripe type-a-thing. While the belly was down: I also ran...
    1. A #2 charging wire from the converter to the batteries in place of the #8 wire.
    2.I ran the backup light wires in the belly while I was there that were previously in a piece of 1/2" EMT running down the frame.
    3.Put a layer of the foil backed bubble wrap stapled to the bottom of the floor. That's in addition to the layer the factory puts in place above the corroplast belly wrap.
    4. Cut a hole from the belly into the kitchen cabinets so the belly heat goes up into the cabinets. On 7 degree nights the cups and plates are ridiculously cold! But not now!
    5. And generally cleaned up all the wiring that ORV installed.
  • Thanks for the great write up.

    I have been thinking about doing this also but my plan is to "T" into the hot shower faucet then throw a solenoid value and pipe it to the fresh water tank. This way I can open the solenoid value for 30 seconds and the RV water pump will move the water.
  • corvettekent wrote:
    Thanks for the great write up.

    I have been thinking about doing this also but my plan is to "T" into the hot shower faucet then throw a solenoid value and pipe it to the fresh water tank. This way I can open the solenoid value for 30 seconds and the RV water pump will move the water.


    After I got mine all done I saw someone that purchased a setup that goes on the faucet/shower head that has a bypass to feed the cold off to the fresh water tank(with an installed water line)till it gets hot. Has some kind of color sensor the senses the heat and indicates you're good to go and flip the lever to the shower.
  • Just Tee into the hot water line at the farthest point from the water heater, and run it back and Tee into the input line at the water heater. Now water will thermo-siphon and will stay hot in the hot water line.

    To save some L.P.G. turn water heater off at night.
  • Dusty R wrote:
    Just Tee into the hot water line at the farthest point from the water heater, and run it back and Tee into the input line at the water heater. Now water will thermo-siphon and will stay hot in the hot water line.

    To save some L.P.G. turn water heater off at night.


    I think........if you did this w/o a check valve, at some point when you're taking a shower the cold water would eventually start mixing with the hot wouldn't it?....or should I say couldn't it?
  • did that in home, also in our Rv many years ago. Works great

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