Shower Water Miser Letting Air into Water Lines
 

Someone in a Facebook group had an issue with air getting into the water filter housing and not allowing the water system to pressurize. The FR Tech Dept said the shower miser could have a bad seal and let air into the lines. I was under the impression the water miser put the rerouted water back into the fresh tank but the diagram shows otherwise.

Don't get that. The whole purpose of the thing is to re-direct water from the hot water line back into the fresh tank until the water gets hot enough to use.

Back to the fresh tank or back to the fresh tank suction line is the same thing.
Regardless, the pump is using recirculated water and not wasting fresh water by dumping it down the shower drain until the water gets hot.

The only thing putting water back into the suction line brings (vs pumping water into the tank) is the 'possibility' of having a place for an air leak on the suction side of the pump. (as mentioned)

EDIT: So, the next question is going to be... "why not just pump it back to the tank?"

Because fresh tanks can (and often are) far away from the pump and the shower.
It simply makes more sense to use short plumbing lines from the shower to the pump than all the way to the tank.

On my current 5th wheel, the fresh tank is 30' from the pump and the shower.
My pump is directly under the shower in the basement. It would take about 4' of hose vs 30' to install a shower miser in my rig.

It's definitely a better way to get the already hot water back into the lines instead of it pouring into the fresh tank where it has to be reheated but the way it is routed it adds complexity and adds another seal that can leak and add air to the system so it won't pressurize.

Well, it's good to be aware of this in case I start having any issues. I have the shower mizer installed from factory.

Where did you find that diagram? I'd like to see a higher resolution copy of it.

Sorry to hijack the thread, but I'm curious about the water miser diagram and trying to match it to my plumbing.

My shower miser return does not go back to the line from the fresh water tank to the pump (as shown in the diagram). Mine loops back to the line coming off the backend of the water pump.

Should/could the shower miser return hose be under pressure? I ask because the small pipe that comes off the shower miser valve developed a split and a fast dripping leak. Fortunate that it was in that spot and just drained down the tub...and filled my grey tank sooner than normal. And this was while the valve was directed to the shower head...not the return hose, so the return hose was under pressure.

If the miser return shouldn't be under pressure when not in use, maybe I have a bad one-way value at the loop connection after the water pump. Or maybe it's not a one-way valve at all.

Looks like the little pipe is a custom part (not from the the ShowerMiser kit), so I'll need to call the dealer or FR for a replacement. In the meantime, I'll cap off the return line at the shower faucet.

Shower Miser return line should not be under pressure. It should go back to either the water tank or at least the suction side of the pump.
The only time it should fill your fresh tank is when the miser valve is engaged. In fact, I sometimes use it to fill my fresh tank when at hookups before leaving a CG.

I thought I post this for others who might be running into the same issue: Our Showermiser seems to have a tiny air leak. Since it feeds back into intake side of the water pump, the water in the hose between the tank and the pump will eventually flow back into the tank.

If we now only briefly turn on a faucet, the pump sucks nothing but air and will not turn off until the faucet is opened again until the air in the feedline has been removed.

Wildcat, question about this method of filling fresh tank: Doesn't it take water from hot water tank? Which presents two issues: Filling your fresh tank with hot water, and issue 2, crap from hot water tank (minerals, calcium) going into fresh tank. I've considered that as a convenient way to move water to fresh tank without manipulating hoses, but haven't for the reasons I mentioned. Your thoughts?

Not necessarily. The Shower Miser valve is on the output side of the shower valve (at least mine is). So it's whatever shower valve you open, hot or cold, that goes back to the fresh tank when you engage the Shower Miser.
So when my purpose is to fill the fresh tank, I just open the cold side and employ the SM valve.
When you are taking a shower, then yes, it will go through the hot water heater and back to the fresh tank. I suppose you could get sediment into the lines/tank in that case depending on how it is plumbed and if it goes through any screens.

Not Wildcat but I just turn on the Mizer and Cold water valve to fill our tank!:usofa: Youroo!!

Also Owners of units with the WMizer system who use PINK Stuff to winterize must pay close attention to how their return line is plumbed! You could induce Pink Stuff into your Fresh Water Tank,not something most people want to do! Remember "Not ALL RVs are plumbed the Same"! Air and Pink method could be employed but with Caution! :usofa: Youroo!!

Thanks guys! I never knew it diverts cold water too. Going to try this trick next time!

On our new unit the "Smart Engineer" decided to locate the Fresh Water Tank Fill on the Entrance door side!? So rather than go to a bunch of Bull Ship I just use the Mizer as our fill while hooked up to the other side where "Everything Else" is normally located! :usofa: Youroo!!

Now I know what the extra line is teed into my suction line for the pump. Thx

If you have the shower miser, but if you can pull the hose free then it is for winterizing.

Our ‘shower miser’ allows air into the hot water heater and once that happens, the air must purged at the hot water heater and the exterior shower. I was in the shower and I had almost no hot or cold water. Our ePro 14fk is less than a year old, the shower is only about six feet from the hot water heater and about 4.5 feet from the pump. It’s pretty useless since would only save less than a quart of water.

We would like to leave it disabled, but it seems to have the effect of introducing air into our entire water system. Failing to be able to effectively turn it off, we seem to be left with the alternative of tearing into the shower valves and routing the water to bypass the useless device. I understand what it’s supposed to do and the theory of its operation. I also have the schematic that is in this thread, but when I was trying to shower, I can hear and feel air being pulled in to the “tub” spigot and that happens regardless of the position of the Shower Miser valve and I can hear the air bobbling in either the fresh water tank or the hot water heater. Due to the short runs of our plumbing, this ‘feature’ is not helpful. It also does such a great job of mixing the hot and cold water in our galley sink faucet.

I really would prefer that the main shower have only a direct connection from the hot and cold water sources when we are not connected to city water.

The shower Miser valve should only be in your shower head line after the tub/shower faucet. So if it is off and has no cracks, the return line (that will have air in it) should not be involved during any faucet usage, including the shower. And if your shower/tub valves are closed, the SM valve is not even in the loop.
If you are getting excessive air in your lines when the SM valve is not employed, I would take it back for service as something is not correct. I'd have them look for the return line having a leak perhaps.
My first thought is you have the SM valve open instead of closed, which will draw air into the return line from the shower head if the return line is plumbed as most are, into the pump supply line, even if you are not using the shower.
For my on-demand water heater, it will not tolerate any air in the lines, so the Shower Miser return line was routed back to the fresh tank, instead of supply side of the pump as most applications with tanks are done. Another option.
And if you just want it gone, you can modify plumbing to remove valve and return line entirely, or just remove the return line from the tee where it goes into the line between the pump and tank and cap everything off.

I have a slightly different situation with the Shower Miser in my ePro 19FD. Mine is plumbed incorrectly. No matter which position the SM valve is in, I still get shower water. I thought the reason was because the SM return T'd in after the pump. I tried plumbing the return into the pump supply side thinking, when the SM valve was open, it would dump into the fresh tank when the pump was not in use, but feed thru the pump when it was on. Nope...no matter which positions the SM valve was in, it filled my fresh water tank...LoL. I plumbed it back to the T after the pump.

As Sarahcat said, it's useless as a "miser" since the hot water run is so short, it comes immediately. What I would like to use the SM for is filling the fresh water tank, but that doesn't work in the present setup.

As it is now, it's a winterizing nightmare to clear the SM return line. The first winter, before I knew of this problem, the SM elbow had water in it and froze and cracked. Had to replace it. That's when I discovered all this.

I need to get back in there and figure out where the improper loop-back is and shut it all up and remove the SM. It's hard to identify which water line is the SM return since it changes from braided white hose to blue Pex like the cold line and the two disappear behind panels under the tub (I can see thru a tiny access panel) and then run behind the bathroom sink/cabinet and behind more panels to the other side of the trailer. I've already had the tub/shower spigot off the wall and can see what's going on behind there. I'm going to have to remove some caulked panels to properly trace the lines.

BTW, during my checkout inspection at purchase, the dealer discovered the fresh water pump was not feeding any spigots in the trailer. It was looping back thru the water pump. They took a couple hours to "fix" it...I assume at the expense on the Shower Miser plumbing.