Shower sump pump?

[malconium]

I have been thinking about using a marine equipment type of shower sump pump as part of the drain water system in my Airstream remodel. Something like the following product:

Shower Drain Pump System*

It seems like using it could allow me to put my plumbing fixtures pretty much anywhere I want without regard for where the grey water tank is placed. The general idea would be to drain the shower and possibly both the bathroom sink and the kitchen sink into this sump pump. The output of the sump pump would then connect to the grey water tank.

Some questions have occurred to me that I would like some help answering from forum members familiar with this type of product or with plumbing issues in general. The questions are as follows:

1.) Since there is a check valve on the output side of the sump pump that decouples the grey tank from anything on the input side of the pump does this effectively mean that it would not be necessary to have any p-traps on any of the input sources?

2.) Since the sump pump creates some suction when it is running does this mean that a sink or shower draining into the sump pump would not really need to have a vent to help it drain?

3.) Just how noisy is a shower sump pump anyway?

4.) Has anyone else used a shower sump pump in their Airstream?

5.) Is this type of device a practical thing to consider using in a travel trailer?

Thanks,

Malcolm

[Excella CM]

Seems like just one more thing to go wrong. Gravity is pretty reliable-that way you start at the drain and it's all downhill from there. You're right about traps and vents, but if the pump fails, you're stuck. If the greywater tank was above the level of the shower, then the pump would be needed.

[muddy_hollow]

Gravity is always simplier but it doesn't always work when the tanks are above the floor. That was the problem that when our 65 GT was retrofitted with above floor tanks.

The sump pump works pretty well. It's not without it's limitations, such as remembering to turn on the power but it is low cost, simple and not noisy. I would say taking a shower or using the sink make about the same amount of noise.

There are other types of diaphram pumps that perform this task less the resevoir for the grey water to collect in.

Pumps make it more complicated, but if you don't mind having them it shouldn't matter what anyone else thinks.

[jgouras]

this would be a nice match with my macerating marine head that pumps to a above floor holding tank.

[malconium]

I suppose that it would be a good idea to add an alternative way to drain water out of the sump pump just in case the pump were to fail at a critical time. I would guess off hand that the type of pump in the unit that I provided the pointer for should be fairly reliable though. I believe that it is basically an automatic bilge pump - not something that you would want to have fail when you are out to sea.

As far as remembering to turn on the pump the good news about this unit is that it has an automatic level switch that turns the pump on when water is present and off when it is gone.

My 1973 31' unit had a side bath but it did not come equiped with a grey tank in that model year. I will likely leave the bathroom in the same place. The best place to put the grey tank seems to be in the cavity behind the rear axle - if I put it under the floor. This location is a bit hard to reach from the shower area for a gravity connection. I thought that if it made sense to add the shower sump pump for the shower that I could consider draining other things into it if that turned out to be more convenient. It does also open up some other options about grey tank placement that I can consider.

The jury is still out on exactly what approach I will end up taking. The thing that I like about the sump pump option, though, is that it does offer so much flexibility for fixture placement.

Thanks for the input guys,

Malcolm

[Forrest]

That's a pretty nifty device. Not only could you use it to pump to a holding tank above floor, but this way you could locate the tank fore, amidships, or aft - regardless of the location of the shower. That really opens up a floor plan.

[boatdoc]

Hi Malcolm; Being in Marine Industry for 41 years, please allow me to give you some input on Rule shower sump pump. It is a good quality unit and with good intent, however here are drawbacks you need to consider.

If installed in the tub, it will not pump the tub dry. It must be installed at the trap exit level, which falls below the floor.
The impeller is a swept bladed plastic, press fitted onto aprox. 3/32" SS shaft as a displacement pump. It is easily plugged up and even more sensitive to hair wrapping around the impeller, thus deflecting the flow of water minimizing or stopping its function. With time, when the impeller gets jammed up too often, it will spin out and melt on the shaft loosing the press fit interference. In the sinks, you would need a relatively tight strainer to keep all debris out.

Since that system would have to be mounted in the belly pan IMHO,
I would recommend a pump with a bronze impeller which would be much more durable and dependable. Accessing it in the belly pan is not my idea of easy maintenance.
My 26' Argosy did not have a gray tank, so I have built a new aluminum above the floor tank. My original intent was to build a sealed [gasket and series of lid retaining bolts, SS collector to house electronic [non mercury] float switch to activate the pump. Small and shallow trap below the tub would drain the shower water into the top of the collector box to activate the switch. On the exit side of the collector box and pump's intake side, would be connected via soft hose coupler. Because the pump would be a strictly a displacement pump, it would not empty the shower tub trap. The discharge side of the pump would need to be connected via one way soft spring loaded check valve, right by the pump outlet to prevent the back flow, and eliminate cycling of the pump.

If you can bear with me a couple of weeks, I can give you more details as I am presently researching the best pump application by inspecting different pumps.
My aim is to pick a pump head design which would be the least susceptible to being clogged with hair, which is just about impossible to keep out of the system. At this time, the bronze headed displacement type impeller seems to be the best option, since it would produce strong flow and minimize wrapping of hair around the impeller.

My gray tank will be piped in via 1.5" Valtera valve into the black tank which will aid in flushing, after the black tank is dumped. Thanks, "Boatdoc"

[lewster]

Originally Posted by malconium

I have been thinking about using a marine equipment type of shower sump pump as part of the drain water system in my Airstream remodel. Something like the following product:

Shower Drain Pump System*

It seems like using it could allow me to put my plumbing fixtures pretty much anywhere I want without regard for where the grey water tank is placed. The general idea would be to drain the shower and possibly both the bathroom sink and the kitchen sink into this sump pump. The output of the sump pump would then connect to the grey water tank.

Some questions have occurred to me that I would like some help answering from forum members familiar with this type of product or with plumbing issues in general. The questions are as follows:

1.) Since there is a check valve on the output side of the sump pump that decouples the grey tank from anything on the input side of the pump does this effectively mean that it would not be necessary to have any p-traps on any of the input sources?

2.) Since the sump pump creates some suction when it is running does this mean that a sink or shower draining into the sump pump would not really need to have a vent to help it drain?

3.) Just how noisy is a shower sump pump anyway?

4.) Has anyone else used a shower sump pump in their Airstream?

5.) Is this type of device a practical thing to consider using in a travel trailer?

Thanks,

Malcolm

Malcolm,

Don't know if this will apply to a DIY re-build, but the RVIA code REQUIRES a p-trap and vent stack on every water drain. The check valve system is not RVIAA approved, although it may work well. This is done to keep any waste water gasses from re-entering the living space of the RV thru the drains.

Sounds like a neat project. Hope it works out for you.

[malconium]

Originally Posted by boatdoc

Hi Malcolm; Being in Marine Industry for 41 years, please allow me to give you some input on Rule shower sump pump. It is a good quality unit and with good intent, however here are drawbacks you need to consider.

If installed in the tub, it will not pump the tub dry. It must be installed at the trap exit level, which falls below the floor.
The impeller is a swept bladed plastic, press fitted onto aprox. 3/32" SS shaft as a displacement pump. It is easily plugged up and even more sensitive to hair wrapping around the impeller, thus deflecting the flow of water minimizing or stopping its function. With time, when the impeller gets jammed up too often, it will spin out and melt on the shaft loosing the press fit interference. In the sinks, you would need a relatively tight strainer to keep all debris out.

Since that system would have to be mounted in the belly pan IMHO,
I would recommend a pump with a bronze impeller which would be much more durable and dependable. Accessing it in the belly pan is not my idea of easy maintenance.
My 26' Argosy did not have a gray tank, so I have built a new aluminum above the floor tank. My original intent was to build a sealed [gasket and series of lid retaining bolts, SS collector to house electronic [non mercury] float switch to activate the pump. Small and shallow trap below the tub would drain the shower water into the top of the collector box to activate the switch. On the exit side of the collector box and pump's intake side, would be connected via soft hose coupler. Because the pump would be a strictly a displacement pump, it would not empty the shower tub trap. The discharge side of the pump would need to be connected via one way soft spring loaded check valve, right by the pump outlet to prevent the back flow, and eliminate cycling of the pump.

If you can bear with me a couple of weeks, I can give you more details as I am presently researching the best pump application by inspecting different pumps.
My aim is to pick a pump head design which would be the least susceptible to being clogged with hair, which is just about impossible to keep out of the system. At this time, the bronze headed displacement type impeller seems to be the best option, since it would produce strong flow and minimize wrapping of hair around the impeller.

My gray tank will be piped in via 1.5" Valtera valve into the black tank which will aid in flushing, after the black tank is dumped. Thanks, "Boatdoc"

Boatdoc,

I am not at all in a big hurry and would welcome the results of your research. Please keep us posted on your progress.

Thanks,

Malcolm

[malconium]

Originally Posted by lewster

Malcolm,

Don't know if this will apply to a DIY re-build, but the RVIA code REQUIRES a p-trap and vent stack on every water drain. The check valve system is not RVIAA approved, although it may work well. This is done to keep any waste water gasses from re-entering the living space of the RV thru the drains.

Sounds like a neat project. Hope it works out for you.

Lew,

I do understand the reason for having a p-trap on a drain. It seems to me, though, that if the grey tank ends up being higher than the check valve that the water in the line from the tank to the check valve would provide the same water trap function that a p-trap would provide. What do you think?

Malcolm

[HiHoAgRV]

I used a similar setup in a Houseboat and the single drawback was it always left a little water that would slosh or, depending how funky I was when showering, would smell. Of course that was pre hair falling out age!

[lewster]

Originally Posted by malconium

Lew,

I do understand the reason for having a p-trap on a drain. It seems to me, though, that if the grey tank ends up being higher than the check valve that the water in the line from the tank to the check valve would provide the same water trap function that a p-trap would provide. What do you think?

Malcolm

Malcolm,

I currently carry 6 check valves in stock at all times. I usually get at least a call a day to replace defective check valves. I just would not depend on them in your described situation.

After all, you want to go camping, not worry about your check valves letting go at any time .

[malconium]

Lew,

Just out of curiosity what type of failures are most typical? Do they open when they shouldn't or do they stick shut?

Malcolm

[lewster]

Originally Posted by malconium

Lew,

Just out of curiosity what type of failures are most typical? Do they open when they shouldn't or do they stick shut?

Malcolm

Actually, I see both types of failures, but failure to work, as in the internal spring and check mechanism does not work and blocks the flow, is the most prevelant. Most check valves found in OEM applications are garbage! They are mostly all plastic with an internal spring that 'RUSTS!!' Cheap is as cheap does!!!

I have also seen what appear to be quality units with the same garbage plastic interiors. I have since sourced an all brass model with stainless springs, and at almost the same price . I really shouldn't complain about it, as I get a lot of business from changing out the inferior models, but it just goes against my grain .

I'll stop ranting now...........................

[malconium]

Can you give us a pointer to a quality check valve of the type that you mentioned? If any of us are going to use one we might as well start with a quality one.

Thanks,

Malcolm

[lewster]

................is the one that I've found to be all metal and the best so far. They are an RV products company, so you should be able to get them at your local RV supply place. Let me know if you can't find them. The ones I stock are all 1/2", and work well for just about all RV uses.

[gregjudy]

I have been thinking about using a pump, also. Then my gray water tank could sit under one of the twin beds in our 57 Airstream Overlander. Both sinks are high enough that gravity would take care of them. I think that a simple 12v pump (that can run dry), with a switch near the shower would work fine. The small pump could be situated just below the drain. As another poster said, one would want an alternative method for letting the water go out. It is a problem..for sure. Not enough room inside the framework under the shower. Let us know how it works if you do it.

[malconium]

Check out this pump that was recomended to me by Boatdoc. When you get to this website go to page 17 of the catalog. Also notice on the same page that there is a "Grey Water Tank" that is a companion product.

http://www.johnson-pump.com/JPMarine..._2007GB_v1.pdf

I found it for sale at the following website for $186.96. I am sure that there are other marine supply places where it would be available as well. I did not find the Grey Water Tank at this site though so I do not know how much it would cost.

Fisheries Supply Search: Viking%252016

While the pump is a bit pricey it sounds like it would be ideal for the purpose. It would be very unlikely to get clogged up with hair from a shower for example. If you want just an on/off switch I think this pump could be hooked directly to the pipes. If you look on page 16 of the Johnson Pump catalog you will see a somewhat higher capacity pump that has an interesting feature - namely a manual crank handle. That could be a way to solve the problem if the power is out.

Malcolm

[brattwurzt]

Malcom, I have installed a radiant system on my house, and it is my opinion that the manufacturer is wrong. I have never heard of a tankless heater that requires pressure to operate. Just think about it, the original intent is to heat hot water for normal user (shower etc). In this normal use, the faucet is open and the water pressure goes to almost nothing and the water exits the system. It's always flow that triggers a tankless unit. I think your unit may be defective. Just my opinion.