Hot water recirculating pump

[Alan24601]

T wastes quite a bit of water waiting for hot water at the sinks. When dry camping this is a problem, any solutions to reduce the waiting time?

[96 Wideglide]

If your sink is a fair distance from your water heater, not much you can do about it.

[gfs1943]

You might look into recirculation systems. In our house we had a recirculation system installed when the house was built, because of the long distance between the water heater and the master bath. This system uses an additional water pipe from the end of the hot water run back to the water heater, with a Taco brand recirculating pump at the water heater to continuously circulate water thru the hot water pipes. Sure makes it nice on a cold morning to have hot water in the master bath within 3 - 5 seconds of opening a faucet, instead of having to wait two - three minutes.

I installed motion sensor controls in the two farthest bathrooms. The recirculation pump starts when motion is sensed in either of those bathrooms, and shuts off about 12 - 15 minutes after no motion is sensed. With that system, the pump doesn't run and waste hot water when no one is in the bathroom(s). I believe you could install the same type of system in an RV. For existing plumbing systems, you can install a pump and valve that uses the existing cold water supply lines to recirculate water back to the water heater.

[SMRDNR]

I'm looking at doing the same thing- we waste several gallons a day getting hot water to the kitchen sink and shower.
looking at a 12 volt recirc pump under the kitchen sink on a switch we could run for a few minutes with a Watts sensor valve kit
would like some opinions on this and if it's doable. I know the S/B pumps are plumbed at the water heater with a timer- I think the switch is a better way to go.

Watt's Sensor Valve Kit For Hot Water Recirculating Pump (0955801) - Amazon.com

Solar DC Hot Water Circulation Pump Cooling Brushless Motor Water Pump 12V 3M | eBay

[Alan24601]

I am not familiar with a Watts sensor, is his a thermostatic valve?

[SMRDNR]

596816 Instant Hot Water Recirculating System Sensor Valve Kit , Hot Water Recirculating Systems, Water Safety & Flow Control - Watts

this is link to the valve from the Watts Company. not sure what type of valve it is, just that it works with a recirc pump.
I'm hoping to be able to put the pump and valve under the kitchen faucet,
unfortunately I won't know until Spring.

[gfs1943]

Originally Posted by SMRDNR

I'm looking at doing the same thing- we waste several gallons a day getting hot water to the kitchen sink and shower.
looking at a 12 volt recirc pump under the kitchen sink on a switch we could run for a few minutes with a Watts sensor valve kit
would like some opinions on this and if it's doable. I know the S/B pumps are plumbed at the water heater with a timer- I think the switch is a better way to go.

Watt's Sensor Valve Kit For Hot Water Recirculating Pump (0955801) - Amazon.com

Solar DC Hot Water Circulation Pump Cooling Brushless Motor Water Pump 12V 3M | eBay

Looks to me like your proposed system would work just fine.

My recirculation pump was initially just plugged into a receptacle so it ran all the time. Not a good idea, as even with well-insulated pipes you will lose heat which causes the water heater to run more than necessary. So I installed a timer, set to turn on the pump about five minutes before I would normally be getting into the shower, and also to try to guess when the wife would want to shower. I used the system that way for a year or so, but could never get the wife's schedule right. So I installed wireless motion sensors in two bathrooms, with a receiver and pump switch plugged into the house wiring. Now, when motion is sensed in those baths, the system comes on. About 10 - 15 minutes after the last motion is detected, the system shuts off. Very cost-effective.

A lot of efficiency depends on where your water heater is located in relation to the hot water point of use; I don't see the need for such a system in my 36-foot coach. But in my S&B, where two bathrooms are almost 75 feet from the water heater, it's a real convenience.

[Alan24601]

It is easier to return the water back to the fresh water tank in our rv. If the supply pump is on and I install a watts valve at the kitchen sink and return the cold water to the fresh water supply tank it seems to me an additional pump to circulate the hot water is not required. Thoughts?

[SMRDNR]

I don't think you will need the Watt's valve if you return it to the FW tank. I will have to see if I could do that also. I think the recirc pump on a switch would be the way to go as long as you remember to hit the switch for a few minutes before you use the hot water.

[SMRDNR]

thanks GFS there is not a lot of room at my water heater so I will need to mount the recirc pump at the kitchen or lav sink. I don't think that should be a problem

[gruelens]

The idea of a pump would work. It may however be counterproductive in energy use for boondocking. Also, there is a considerable expense to setting up the system. Not too mention the work required to install such a thing.

Might I suggest a K.I.S.S. system. We always catch the shower water while waiting for it to get hot (when drycamping.) It can then be used in a variety of ways. One is, take a plastic 1 gallon milk jug and drill about 6 small holes in the cap. Use it to rinse the commode after a #1 (you need to have a water shutoff on commode for boondocking.) You can also use the "caught" water to rinse dishes. Keep it for drinking if you have good potable water in your tank. If possible just pour it back into FW tank. Note: if you are serious about saving water, stand in a large dishpan while showering. Use that gray water to flush the toilet.

In other words repurpose the water in some way. This saves the hassle, expense, and energy consumption of a recirculation pump.

[Tony Lee]

Hot water is just cold water that you spend money on propane or electricity to heat. Unless your hot water lines and the return line are very well insulated, you are going to use energy to reheat that water over and over, plus electricity for the pump as well. It becomes a matter of wasting a bit of water each time you need hot water or wasting energy all the time you are not using hot water.
Different in a big hotel with extensive piping, but not so useful in a small motorhome.

[Old Bounder]

This is an idea that I've toyed with for years, but have never done anything about.

If you boondock a lot, you know that conserving water can be more important (at any given time) than conserving propane.

Here's a diagram of such a system. It's not my design, but I don't know who to give credit to. Your logistics (such as where is the "END" of the hot water line) will determine the exact design parameters.

[JFXG]

I put a system like that in my boat some years ago, with paralleled manual switches in the head and at the galley sink. IIRC I had to run the pump about ten seconds to get hot water. Worked great.