Adding a circulating pump for quicker hot water

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Adding a circulating pump for quicker hot water

October 13, 2010, 09:20:10 pm

For all three of my hot water sources (Galley, Bathroom, Shower) I waste a lot of water and add it to my grey tank waiting for hot water. In a campground this is only an annoyance. When dry camping for an extended period it is a major issue. Has anyone added a pump with a switch to send the cooled water in the hot line back to the Aquahot?

Re: Adding a circulating pump for quicker hot water

Reply #1 – October 13, 2010, 09:25:45 pm

Quote from: Harvey Nelson – October 13, 2010, 09:20:10 pm

For all three of my hot water sources (Galley, Bathroom, Shower) I waste a lot of water and add it to my grey tank waiting for hot water. In a campground this is only an annoyance. When dry camping for an extended period it is a major issue. Has anyone added a pump with a switch to send the cooled water in the hot line back to the Aquahot?

Harvey,
I don't have a suggestion for how to recover the hot water recirculation. But, I read once in some publication a suggestion a reader sent in that suggested to have a pail in the shower to capture the cold water intil the hot water is available. This captured water in the bucket can then be used for other purposes (not drinking).

Re: Adding a circulating pump for quicker hot water

Reply #2 – October 13, 2010, 09:58:14 pm

Quote from: Harvey Nelson

For all three of my hot water sources (Galley, Bathroom, Shower) I waste > a lot of water and add it to my grey tank waiting for hot water. In a > campground this is only an annoyance. When dry camping for an extended > period it is a major issue. Has anyone added a pump with a switch to > send the cooled water in the hot line back to the Aquahot?

Quote
Harvey,
I don't have a suggestion for how to recover the hot water recirculation. But, I read once in some publication a suggestion a reader sent in that suggested to have a pail in the shower to capture the cold water intil the hot water is available. This captured water in the bucket can then be used for other purposes (not drinking).

Peter & Beth Martin
Cincinnati, OH
1997 U270 WTBI 34' (Forrest)
Coach Build No. 5156
2004 Honda Element EX (Henry)
petermartin@fuse.net

Hi Harvey,

I have done something like this for the shower. I probably should do it for the kitchen sink too. In this first try no pumps are added. Alternatively, a circulatory piping system to all three fixtures should would work well and save even more water.

So here is what I did: I put a Pex "T" in the hot water line to the shower - in the bedroom closet behind the shower faucet. The output from this "T" goes through a 1/4 turn valve which is returned to the fresh water tank through 1/2" flexible plastic tubing (siliconed, high into the tank). A 12 volt solenoid valve might be more convenient to actuate because the switch for it could be located in the bathroom.

So... when I dry camp and want to save hot water, I open the valve in the closet, feel for the water to become hot in the valve as it returns to the fresh water tank - then shut it off. This reduces wasted water to the shower from two quarts to one cup.

EDIT:
Oops, I hit the send button before I signed...

Others probably have devised better methods to save hot water. Please respond...

Re: Adding a circulating pump for quicker hot water

Reply #3 – October 13, 2010, 09:58:26 pm

On those rare occasions when we dry camp, we catch that lukewarm water in a bucket and either toss it outside or use it to flush the toilet. This is a cheapskate's solution to the problem you describe.

Re: Adding a circulating pump for quicker hot water

Reply #4 – October 14, 2010, 11:43:32 am

I boondock lots so this hot water recovery is important to me.
In my previous motorhome, the shower was beside the water tank in the rear and hot water tank was over the sink in the center. I replaced a "90" in the hot line near the shower with a "T". Installed a hand valve after this new "T" and installed a "T" in the water pump feed line. An accesss door in shower base allowed me to turn on recycle line and feel for hot water. This also served sink.

In my U320 I am in the process of installing 1/2 inch plastic piping with a "T" on hot line below sink. I am running this pipe along same route as hot line. It will terminate below hot water heater with a water pump which will have the output connected to the cold line where the accumulator tank was connected. The pressure switch for the ciculating water pump is bypassed and not used. This way I can leave the water pump on long enough to heat the water lines and surrounding areas without heating the water in my fresh water tank. I will use the "water fill" switches in kitchen and bath for circulation.

I replaced the original water pump and accumulator with a smart pump and will use the original water pump for circulating.

I have replaced the "electric water fill valve" with a manual globe valve which allows throttling because I probably will never use this as I am seldom connected to water. I intended to install the "electric water fill valve" for hot water circulation with a circulating pump used in boats. The circulating pump pressure was insuffient to open the "electric water fill valve" and I was unable to find a back water valve which opens with very low pressure.

For filling the fresh water tank from a pressure water supply, I installed a female hose connection in the end of the water tank drain line with a plug to keep dirt/bugs out. I will add lights behind the water tank which will allow seeing how full the water tank is by looking below the water heater. I use a flash light now.

Re: Adding a circulating pump for quicker hot water

Reply #5 – October 14, 2010, 11:54:57 am

Quote

I replaced the original water pump and accumulator with a smart pump and will use the original water pump for circulating.

Could you pleaase explain what is a "smart pump"?

Re: Adding a circulating pump for quicker hot water

Reply #6 – October 14, 2010, 12:46:52 pm

Quote

Could you pleaase explain what is a "smart pump"?

http://tinyurl.com/2d9cw23

Re: Adding a circulating pump for quicker hot water

Reply #7 – October 14, 2010, 01:09:37 pm

Man!
This topic can get complicated. How about adding a temperature sensor in the hot water line preset to say 110 degrees and wiring an LED or a sound alarm to be able to tell when to switch the valve. Or, better yet, wire a solenoid activated valve to perform the switching function?

Now we're talking...

Re: Adding a circulating pump for quicker hot water

Reply #8 – October 14, 2010, 01:41:21 pm

Quote

Could you pleaase explain what is a "smart pump"?

http://tinyurl.com/2d9cw23

OK - it's a trademark name - what's so special about it?

Re: Adding a circulating pump for quicker hot water

Reply #9 – October 14, 2010, 01:57:22 pm

Quote

Could you pleaase explain what is a "smart pump"?
Quote
OK - it's a trademark name - what's so special about it?

It is a variable speed pump.

Re: Adding a circulating pump for quicker hot water

Reply #10 – October 14, 2010, 08:18:39 pm

Harvey,
I have added "Hot Water Recirculation" to my '01 320 & '07 Nimbus.
I built a solid state timer to drive a solenoid valve whose input is connected to the hot line of the shower diverter and the lav hot water spigot.(place the tees as close as you can)
The timer starts when the shower light is turned on. (it runs for 2 min., or any increment you want)
The output of the sol. valve is routed back to the fresh water tank.
You may get a coffee cup full of cold water when you turn on the spigot.
You don't need a pump.
I have dwgs., parts list, and pics if you're interested.

Dick Ward #14393
'07 Nimbus
'00 Ford Windstar

Re: Adding a circulating pump for quicker hot water

Reply #11 – October 14, 2010, 09:13:06 pm

Hi Dick,

Where did you find the water solenoids for your hot water saver project and what size are the ports? I've done something similar an need solenoids for the Pex tubing.

Jim 202 U320
Van Buren, OH

Quote

The output of the sol. valve is routed back to the fresh water tank.
Dick Ward #14393
'07 Nimbus

Re: Adding a circulating pump for quicker hot water

Reply #12 – October 15, 2010, 11:38:55 am

Quote from: Richard E. Ward – October 14, 2010, 08:18:39 pm

Harvey,
I have added "Hot Water Recirculation" to my '01 320 & '07 Nimbus.
I built a solid state timer to drive a solenoid valve whose input is connected to the hot line of the shower diverter and the lav hot water spigot.(place the tees as close as you can)
The timer starts when the shower light is turned on. (it runs for 2 min., or any increment you want)
The output of the sol. valve is routed back to the fresh water tank.
You may get a coffee cup full of cold water when you turn on the spigot.
You don't need a pump.
I have dwgs., parts list, and pics if you're interested.

Dick Ward #14393
'07 Nimbus
'00 Ford Windstar

Yes, I would be very interested in seeing the drawings, parts list and pics. Thank you very much.

Morris

Re: Adding a circulating pump for quicker hot water

Reply #13 – October 15, 2010, 11:53:32 am

Dick,
I would also appreciate a copy of the dwgs., parts list, and pics.
Thanks!
Paul
36' 2000 U320

Re: Adding a circulating pump for quicker hot water

Reply #14 – October 15, 2010, 12:17:42 pm

Dick,

I would also appreciate a copy of the dwgs., parts list, and pics.

Jim

Re: Adding a circulating pump for quicker hot water

Reply #15 – October 15, 2010, 08:03:05 pm

Quote from: Paul Wildenstein – October 15, 2010, 11:53:32 am

Dick,
I would also appreciate a copy of the dwgs., parts list, and pics.
Thanks!
Paul
36' 2000 U320

Re: Adding a circulating pump for quicker hot water

Reply #16 – October 15, 2010, 08:26:09 pm

Dick,

I received no attachements. See below, maybe you replied to Paul.

Jim

Quote

Quote from: Paul Wildenstein on Today at 08:53:32 AM
Dick,
I would also appreciate a copy of the dwgs., parts list, and pics.
Thanks!
Paul
36' 2000 U320

Richard E. Ward
2007 Nimbus

Re: Adding a circulating pump for quicker hot water

Reply #17 – October 15, 2010, 11:54:38 pm

Quote

I have added "Hot Water Recirculation" to my '01 320 & '07 Nimbus.
I built a solid state timer to drive a solenoid valve whose input is connected to the hot line of the shower diverter and the lav hot water spigot.(place the tees as close as you can)
The timer starts when the shower light is turned on. (it runs for 2 min., or any increment you want)
The output of the sol. valve is routed back to the fresh water tank.
You may get a coffee cup full of cold water when you turn on the spigot.
You don't need a pump.
I have dwgs., parts list, and pics if you're interested.

Here is a copy of Dick Wards File.

Re: Adding a circulating pump for quicker hot water

Reply #18 – October 16, 2010, 10:26:15 pm

Quote

To: pwyatts@hotmail.com

"Quote:
I replaced the original water pump and accumulator with a smart pump and will use the original water pump for circulating.
"

Could you please explain what is a "smart pump"?

Larry Rubin
2004 U295 38'
2005 Element Toad

More replies may be posted, but you won't receive any more notifications until you read the topic.

Sorry for the delay, we are out camping and I have not been online.

A smart pump is a variable speed pump which maintains water pressure to very close tolerances. It provides water flow as if connected to city water. No surging.

Wyatt

Re: Adding a circulating pump for quicker hot water

Reply #19 – October 17, 2010, 01:42:27 am

This exactly what my first motorhome had. It was a 1972 Revcon, and it had a water saver pushbutton switch in the bathroom. Press it, and a solenoid would send pressurized hot water into the fresh water tank for some predetermined number of seconds. Looking back, I want one in my Foretravel someday soon. That old Revcon was way ahead of it's time in some ways.

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