Water pump question GPM?

[tommymsw]

So I have a small class C that I really intend to just use at camp sites. So the water pump will not be needed most of the time. I really only need it to flush the toilet on trips (I think... I have never actually been in an rv before).

My question is.. if I get a well reviewed 1.2GPM pump off Amazon... Will it be enough to flush the toilet?

Also, on the off chance that I want to shower... Will it be TERRIBLE or tolerable. I read that a house shower only uses 2.3GPM so I figure it should be like a weak shower. I am OK with that as I would just be using it in extreme cases.

I figure experience is kind and want to make sure this is not a STUPID idea. Again... I am OK with low pressure for the shower as long as it will at least work? But the main thing is to flush the toilet. 🙂

[DrewE]

If it's not priming, check that there isn't a small leak in the pump intake plumbing letting air in, or that there isn't a setup to let it pump antifreeze into the plumbing system (that's set to the antifreeze inlet). It may also help to have the fresh water tank completely full if it is not full now.

[j-d]

Most RV water heaters have Bypass Valves. They direct water around, instead of into and out of, the WH. So you can drain it for winter and not get antifreeze in it like many run into their plumbing lines. If it's in Bypass, it won't put your pump in an air bind. If the WH is in play, then it has to be full.

Can you post the Make/Model of the Pump you have now, and/or a picture of it? If it's a Shurflo type, the pump part can be cleaned or replaced. That's given the motor part of it runs.

[tommymsw]

j-d wrote:
How is the pump you have now, connected to your unit's plumbing? The one you pointed out is hose barb fittings. The ones DrewE linked use special snap-on fittings.

There's a lot to be said, for getting a "direct replacement" where we disconnect one and install the other. Same plumbing, maybe even same screw holes. It's worth it to me, to pay a little more, and get that easy install, if I can.

Frankly, that Amazon pump looks like it would work. I was ready to buy one like that or similar, for the wash up sink in our boat. Then I found I could repair the pump that was already there. Dirty brushes and commutator segments...

Have you tried to clean your pump up and see if it works?

Yea, it has screw on attachments now. I have considered that. I am still going to mess with the pump a but to figure it out. It runs when it is on, just doesn't seem to be pumping water. I may not have given it enough time.

Also, my hot water tank was bone dry. Not sure if it won't pump unless the tank is full?

[j-d]

How is the pump you have now, connected to your unit's plumbing? The one you pointed out is hose barb fittings. The ones DrewE linked use special snap-on fittings.

There's a lot to be said, for getting a "direct replacement" where we disconnect one and install the other. Same plumbing, maybe even same screw holes. It's worth it to me, to pay a little more, and get that easy install, if I can.

Frankly, that Amazon pump looks like it would work. I was ready to buy one like that or similar, for the wash up sink in our boat. Then I found I could repair the pump that was already there. Dirty brushes and commutator segments...

Have you tried to clean your pump up and see if it works?

[tommymsw]

DrewE wrote:
Is the little pump you're considering an on-demand pump with a pressure switch, or one that would run continually (or try to)? You want an on-demand pump.

Electronics Goldmine has some good prices on appropriate pumps: 1.9 gpm for $40 or 2.9 gpm for $45 plus perhaps a bit more necessary fittings. I think either of these would be rather more satisfactory than a 1.2 gpm pump.

The one I looked at was on demand.
https://smile.amazon.com/Seaflo-Diaphragm-Pressure-Caravan-Marine/dp/B00DLKT4OO/

thank you for the links to the other ones. I will have to consider those also. Although with shipping, they are over $60. Still not much money though.

[DrewE]

Is the little pump you're considering an on-demand pump with a pressure switch, or one that would run continually (or try to)? You want an on-demand pump.

Electronics Goldmine has some good prices on appropriate pumps: 1.9 gpm for $40 or 2.9 gpm for $45 plus perhaps a bit more necessary fittings. I think either of these would be rather more satisfactory than a 1.2 gpm pump.

[tommymsw]

I have a bad hot water heater and I am likely not even going to replace that. At least anytime soon. Not sure if I would even use it. So one summer to just try it out and I will have a better idea of how much I am going to do in it.

[tommymsw]

So I actually saw the smaller pump in an article about what pump to buy. While they did say most people would use a 3.5, they said that THIS smaller model had great reviews. It is 1.2 GPM 35 PSI.

Now I am NOT going to "live" in the RV. I am sure I will eventually fall in love and buy a bigger RV as seems to be the case. But for right now, I am just feeling it out. Maybe take it to tailgate a football game, or save some money on a hotel room and sleep in a rest stop one night.

I get that "bigger is better" and I do not expect much. I just wanted to make sure it was not a TOTAL noob mistake.

Yes the RV has an old pump.. But it does not seem to be pumping, I did the testing, but it just is trickling out from the output side. It also is old and the new self priming, run dry pumps seem like a better idea. The original pump is for SURE small. Again, this is an old '86 rv that was a Chevy van. It is SMALL and nobody will be showering while running water. It will just ever be me and my son.

I plan on bottled water, paper plates and likely no showering. But probably using the rest room. 🙂 MAYBE once I get into it... a "dry camp" for a day or two. But for $30, I can just upgrade the pump later.

I am sure many of you are WAY more serious... and why I respect your opinions.

[rjstractor]

1.2 GPM is enough to fill up the toilet and flush it, but to give the bowl a good rinse as it might need at times it takes water flow. 1.2 doesn't sound like much at all. Another factor is the pressure at which the flow is rated. 1.2 GPM at 50 psi might provide adequate performance but the same flow at 10 psi certainly will not. You literally won't get much more than a dribble out your shower head. Personally, I'd spend a few bucks more and get a pump designed and specced specifically for RV use.

[bukhrn]

OK, My question to your question, Why are you looking at a pump on Amazon, does your Class C not already have a pump?
I don't know about GPM, flow rate, pipe sizes and all those technicalities, but I do know that we have taken many, many showers in our class c and had no problem with pressure.
As far as enough pressure to flush the toilet, that is a Non Issue, as you simply lift the pedal till the bowl get to the needed level, then push the pedal down, WOOSH.

[enblethen]

If you are looking at the ones, for about $29, it does have much pressure. It is only rated at 35 pounds.
you would be better off with one that is around 50 PSI output.
Yes, it is a little more money, but you would be happier!

[2oldman]

Dutch is correct, and I might add the pump pressure is more important than volume in being able to overcome the restrictions.

60psi is too much, and 35 is about right. I wouldn't go lower.

[DutchmenSport]

Well, you are partially correct. Just because the pump can pump 3 GPM, or 1.2 GPM is only half the factor. The other half is how big in diameter the water lines are in the camper. Smaller lines will flow less water. So even though a pump may be capable of 1.2 GPM, the lines might be so small it only pumps 1/2 GPM.

Shower head almost always water saver reducers built into them to prevent the maximum flow, even possible with a 1/2 inch diameter pipe with water behind it. The actual opening in that shower head may be 1/8 inch, restricting the amount of water that can pass through, thus taking longer to run that 1.2 gallons.

Your toilet just flows water. Whatever the valves the water has to pass through are set for, will really determine how much (or how fast) the water will flow (regardless of pump size).

So actually, taking a shower, you'll probably not see any difference between a 1.2 or a 3.0, because of the shower head restricting flow. Same is true for the toilet.

Now, if all your water lines are 1/2 inch (which most are in RV's), you may notice a difference in output at the kitchen sink, as kitchen faucets usually have no restrictions (although some of the newer ones do).

Hope this helps.