RV Plumbing Diagram

[codgerbill]

I was recently at a rally and the neighbor coach mentioned a way to not have to dump the cold water into the gray tank while waiting for the hot water to make it to the rear sink faucet or shower. He told me that he had a switch (for an additional pump) mounted in the bathroom near the sink and turned it on prior to turning on the hot water faucet. After a very short period he would then turn off the switch, and then turn on the hot water faucet. There was no more running the water to wait for the hot water. I had a drawing that I made for my motorhome (Winnebago product) and I added the above mentioned system to show the additional pump and fittings to make the system work as was shown to me. I dont know if it applies to other RV's in general.

[puttin]

Nice gadget!

[Engineer Guy]

Nice setup and execution, and a great drawing!

We Solar Geeks have been doing this same Recirc 'Loop' in Home Systems. You can also put on a Timer to have the Loop on only at certain times of day. The Manual Pump Start/Override Switch, especially in the relative square footage of an RV, is excellent. These Systems have gone 'mainstream, and Pumps can now be bought at Big Box Stores, thought pricy... One has to be mindful of the high temp Spec on plastic Housing RV-style Pumps, however.

Unless there's some one-way Check Valves installed, unique to a RV Model, this super Recirc idea should work in about any RV.

Some of us use +12 VDC Pumps anyway so that House Functions operate during Power outages, or off of PV Panels.

I'm going to be plumbing up a Garage/Workout Area/Shop near-term, and will be using all Trailer/off-Grid Components. Just because...

Turning on a lil Recirc Pump manually using a 'spare' Button on a multi-Function Garage Door Opener would be a good use for that Button. I'd been wondering what to use it for.

Home Sprinkler Controllers are also good for 6 timed functions around the House. They run from low Voltage, and don't have to control Sprinklers...

[mahon1993]

We use a low tech method while waiting for the hot water in the shower. We have a small two gallon bucket we use to collect the cold water before the hot water arrives and then use the water in the toilet.
Greg

[LadyFitz...]

Quote:

Originally Posted by Engineer Guy ...Home Sprinkler Controllers are also good for 6 timed functions around the House. They run from low Voltage, and don't have to control Sprinklers...

Now that is downright clever! Thanks for the tip!

[JimM68]

Hmmm, I like it. Wonder where I'd find the cold feed to the hot water heater in my Knight?
I just put in a new shur-flo extreme, could use the olf water pump to recirc...

[Romeo]

CodgerBill,

Ok, so the "added" pump initially pumps the water that has cooled down in the hot water line, back into the cold water inlet to the hot water tank which in turn circulates the hot water, and replaces the cooled hot water with hot water. One would then turn off the "added" hot water circ pump and open the tap which would now flow hot water.... Right?

But then when one is done washing their face with hot water and wants to take their night-time Aleve with cold water from the cold water tap, wouldn't it be hot, requiring one to run the hot water out of the line before getting cold water? So then it wouldn't it be the same as running cold water while waiting for the hot water... running hot water waiting for the cold water.

It seems to me that a standard hot water recirc line would be a better solution, although, maybe harder,or almost impossible, to install (???).

For those that don't know what a "standard" hot water recirc line is; it's a line at the farthest point from the hot water heater that is run back to the hot water tank so that hot water continually recirculates so the the "hot" water is always hot.

BTW... you didn't show the direction of flow through the pumps, but I think I figured it out.

[codgerbill]

Ron,

I could be wrong but..................
The system circulates the water in the loop between a connection ahead of the bathroom hot water faucet and the hot water tank. I would guess that if you turned on both the hot and cold water taps in the bathroom you would get hot water from the cold water tap. The gentilman that showed me his system has had it for several years and (according to him) has had no problems.

I would also surmize that one could install a check valve if one was concerned about hot water in the cold water system although the gentilman that showed me this system said he had not had a problem regarding hot water in his cold water system.

Thank you for mentioning the direction of flow for the pumps. I had not included flow direction because I print it on a 8 1/2" X 11" piece of paper and unless you can zoom in on parts of the drawing it (the directional arrows) would be difficult to see and might look like a piece of dirt or something.

I printed it out and laminated it and keep on the coach to help me winterize the system. My feeble memory doesnt need to be relied on because I have a drawing (and printed instructions) to show me what I have to do to winterize.

[Romeo]

Quote:

Originally Posted by codgerbill I would also surmize that one could install a check valve if one was concerned about hot water in the cold water system although the gentilman that showed me this system said he had not had a problem regarding hot water in his cold water system. I printed it out and laminated it and keep on the coach to help me winterize the system. My feeble memory doesnt need to be relied on because I have a drawing (and printed instructions) to show me what I have to do to winterize.

As I was looking over your diagram, I thought that a check valve just upstream of where the new pump discharge connected into the water heater supply line would solve the problem.

Good idea on the laminated copy.... and nice drawing.

[Possum]

The new plumbing is an enclosed separate system and should not back feed to the existing cold water as there is no reason for that part of the system to let hot water run there.

I think that this could be a new project for our unit too.