Forum Discussion

TUCQUALA's avatar
TUCQUALA
Explorer
Jul 26, 2015

Bath hot water slow, wasted.

Having a rear water heater and a forward-of-center bath requires that we run the hot water for a fairly long time to use comfortably, esp in the mountains and the cool. Dry camping means that a good amount of water is going to waste into the gray tank.

I know that many will say to just use a receptacle to catch the unused water. Yep, easy, and not what I'm asking about.


If a second water pump was installed in the bath area, plumbed between the hot & cold supply lines, and pressure set to be higher than the main pump, would this function to push the cold "hot" water into the loop back to the water heater via the cold supply? Like a circulation system in houses for the same problem.

I think that the pump internal check valves would prevent cross flow on one side when not in use, and maybe a 12v solenoid in parallel with the pump to close off the cold side if necc.

Just one of many ideas that have infected my mind to help with this proble. Such as a new line and valve that would send the cold "hot" water back to the FW water tank. Lot more involved with the underbelly on this trailer. Still thinking of other ways!!!

7 Replies

  • Jframpey's avatar
    Jframpey
    Explorer
    Jul 27, 2015
    christopherglenn wrote:
    You put this valve at all the sinks and shower you want instant hot water at.
    You plumb this pump between the cold water and water heater feed, pushing water into the water heater. To avoid hot water flow reductions, you can put in a check valve in parallel, so the main water pump bypasses the circulating pump when you use hot water, and the small pump keeps things moving when you are not.


    Yep, that's the one... I put this pump under my bathroom sink between the hot and cold lines. Attached a switch with a thirty second timer. When I walk into the bath and want hot water I push the button and 15 seconds later.... Ahhh!
  • christopherglen's avatar
    christopherglen
    Explorer
    Jul 26, 2015
    You put this valve at all the sinks and shower you want instant hot water at.
    You plumb this pump between the cold water and water heater feed, pushing water into the water heater. To avoid hot water flow reductions, you can put in a check valve in parallel, so the main water pump bypasses the circulating pump when you use hot water, and the small pump keeps things moving when you are not.
  • jodeb720's avatar
    jodeb720
    Explorer
    Jul 26, 2015
    years ago on this site, someone had found a very low current draw (6watts) 12 volt pump - that was plumbed into the cold water feed for the hot water - with a check valve.

    He had it set up with a temperature switch (snap switch) which switched the pump on and off.

    Later he used to heat his coach using radiators silently.

    it's more than feasible.
  • TakingThe5th's avatar
    TakingThe5th
    Explorer
    Jul 26, 2015
    My solution doesn't solve your problem directly, but I have a grey water system that flushes the toilet using shower water. So I don't mind running the water a bit because I'll be using it again for flushing anyway.

    I put in my gray water solution because my fresh water tank would be too empty while the shower grey tank was too full. With the grey system in place I now can extend my stay by several days.

    So essentially you don't capture the water and put it back in the fresh water tank, instead you use it for flushing and save the trip. But yes-my tank math works for me in my circumstance but your situation may be different.
  • Johno02's avatar
    Johno02
    Explorer
    Jul 26, 2015
    Hat water recirculation systems are very common, especially in industrial or commercial applications, not so much in homes. Although I have seen several. Yes, they do save water, at the cost of reheating the circulated water all the time. Some systems have lertover heat from other sources, so it works fine for them. Think about good pipe insulation as another option.
  • doughere's avatar
    doughere
    Explorer
    Jul 26, 2015
    There is not enough detail in your posting to understand what you are proposing.

    If you can't/won't save the water; you can install a small circ pump to circulate the hot water from the hot water line at the sink back to the input of the HW tank. A local thermostat in the water line could control this pump, or a switch to run briefly before using hot water. This would use electric power, and of course waste energy to reheat the water in the lines. Dry camping, both of these often in short supply.

    Doug
  • newman_fulltime's avatar
    newman_fulltime
    Explorer II
    Jul 26, 2015
    get a 5 gal water bottle catch the cold water and put it back into the fresh water tank after showering

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