Noisy water pump - making it quieter

[ShrimpBurrito]

Originally Posted by brulaz

Another irritating issue. I mentioned earlier that the water pump was noisy. Finally got around to reading the Shurflo installation and operating manual and it says: "The pumps ports/strainer *should not* be connected to plastic or rigid pipe. The pump's normal vibration may transmit through rigid plumbing causing noise, and possibly loosen or crack components."

Well guess what? While on the tank side of the pump Trailmanor used a nice, soft plastic tubing with braid reinforcement, on the other side the pump is attached directly to the hard plastic plumbing used throughout the rest of the water system. I bet that's where the noise is coming from. All they needed to do was put about a foot of the soft stuff between the pump and city water input tee. What were they thinking? I guess they just weren't.

I have a fair amount experience with the water pump. And in fact, I have an identical model as in the TM that I use as a water transfer pump, as it actually used to be installed in my TM where it made a racket. When held in my hand, the pump I use as a transfer pump is not quiet silent, but very quiet, when in use. The difference? Yes, if you replace the PEX with flexible reinforced tubing, that will do alot to reduce the noise. But be careful not to create new high points in the plumbing that would prevent water draining when you open the drain valves. That is my guess as to why TM doesn't use flex tubing -- the high points are harder to control.

It would also be of great benefit if you mount the pump to a shock absorbing pad -- something like a thin sheets of plywood with a piece of semi-rigid foam or rubber in between. The one sheet is mounted to the wall, and the pump is mounted to the other sheet. The screws mounting the pump should not extend far into the foam, as they will transmit the vibration.

If you do these 2 things, your water pump will be VERY quiet.

Dave

Originally Posted by ShrimpBurrito

... be careful not to create new high points in the plumbing that would prevent water draining when you open the drain valves. That is my guess as to why TM doesn't use flex tubing -- the high points are harder to control.

It would also be of great benefit if you mount the pump to a shock absorbing pad -- something like a thin sheets of plywood with a piece of semi-rigid foam or rubber in between. The one sheet is mounted to the wall, and the pump is mounted to the other sheet. The screws mounting the pump should not extend far into the foam, as they will transmit the vibration.

If you do these 2 things, your water pump will be VERY quiet.

Thanks Dave.

There is only a very short section (~1') of horizontal hard plastic tubing between the pump and the tee to City water. So I don't think it would be difficult to fit some soft plastic tubing there that would not sag. Anyway I'll make sure it doesn't. And no, I don't think it was a deliberate design decision on Trailmanor's part. I think it was an oversight.

The pump is already mounted on rubber feet and then on some sort of shock pad. I can't get to it right now, but will look more closely later in the week.

Anyway, it's good to hear that this can be easily fixed.

Bruce

Originally Posted by rumbleweed

Use a 2 or 3 foot square piece of 3/8 ply and glue carpet to the bottom side.

I've got some scraps of 2" rigid insulation foam that could be used as well. I'll try that.

[ShrimpBurrito]

Originally Posted by brulaz

There is only a very short section (~1') of horizontal hard plastic tubing between the pump and the tee to City water. So I don't think it would be difficult to fit some soft plastic tubing there that would not sag. Anyway I'll make sure it doesn't.

Replacing 1' of PEX with 1' of reinforced (make sure you get reinforced) plastic tubing will definitely help, but ideally, you'd want to make a loop in the tubing, making it maybe 3' long. The loop will absorb the vibrations better than a straight 1' section. If you do that, be careful you don't create any low points if you want to continue using the gravity drains.

The pump is already mounted on rubber feet and then on some sort of shock pad. I can't get to it right now, but will look more closely later in the week.

Those rubber feet help, but they are not enough for the pump to achieve quiet operation. The real problem is the screws -- they are connected to the pump and the wall/mounting surface, and transmit the vibrations directly to the TM wall (or wherever it is mounted), which in turn vibrates everything on earth. You need to interrupt that transmission so that whatever means you use to mount the pump assembly as a whole does not touch the pump. That's where the plywood-foam-plywood sandwich comes in, and that's why it's important that you use 2 sets of screws -- one set to mount the entire assembly to the wall by going through the one sheet of plywood, and another set to mount the pump to the other sheet of plywood.

It's easy to see the pump's quiet potential -- disconnect the plumbing, unscrew the 4 mounting screws, and turn it on. It's not an impeller pump, and in fact has little moving parts, so you can run it dry without any problems. You'll hear more noise than you would if it were pumping water through flexible tubing, as you'll hear air coming out of the intake/outtake ports which ordinarily would carry water, but I guarantee you it will be much quieter than now. The biggest difference you'll notice is that the noise you do hear is isolated to the pump itself, and you'll realize how much of the noise you hear in the trailer is actually transmitted noise.

Dave

One of the things we want to do with the Elkmont is spend a lot of time dry camping. That means using the battery, the pump and the propane furnace, frig and water heater more than usual.

One our initial problems was how noisy the 12 V Shurflo pump was. In part that was because it did not have flexible tubing installed on both sides, but only between the pump and the tank.

So I finally got around to following ShrimpBurrito's advice and added 3' of flexible, reinforced 1/2" I.D. tubing between the noisy pump and the hard PEX stuff.

Fairly simple modification. Unscrewed the pump from the PEX and added a straight, male 3/4" pipe to 1/2" I.D. hose adapter to the PEX end. To the pump end added a 90 degree angle, female 3/4" pipe 1/2" I.D. hose adapter. Used teflon tape on the threads. Soaked the hose ends in hot water then pushed them on and clamped.

From the PEX end, the hose runs horizontally (it seems to drain ok, but I'll probably check each winter) behind the pump into the furnace area and then through a small hole in the partition back into the battery compartment and to adapter at the pump. It's not close enough to the furnace for that to be an issue. I'll be adding bits of foam where the hose touches stuff and will post a picture when I get my camera back.

This mod really cuts the pump noise. The pump itself is already mounted on a rubber/flexible support, so I didn't add anything more there.

The next plumbing project is putting a 2 gal pressure tank under the bottom shelf in the rear, passenger side corner.

[ShrimpBurrito]

Excellent! If later on down the line you find you want to quiet the pump even more, you can always add the foam mounting pad, but adding the tubing is a major improvement IMHO. Of course, now it's easier on the ear to let the water run freely!

The pressure tank is also a welcome mod. If I had room for a 2 gallon unit, I would have installed it, but since I'm super tight on space, I put in a ~22 oz unit. It definitely cuts down on cycling, but obviously the bigger the better in this case, so the 2 gal unit should be great. Let us know how it turns out.

BTW - if you need to tie into PEX at some point and don't have a crimp tool, the Sharkbite connectors work perfect, as advertised. So far, no leaks.

Dave

If money is not an issue but space and noise are, you can try one of the micro-controller controlled pumps. When needed, they run continuously at a variable speed to eliminate the pulsing sounds.

[ShrimpBurrito]

I actually looked at the variable speed pumps at the time, and was prepared to buy one. But after purusing other forums about the topic, I decided to stick with what I had. The variable speed pumps will make just as much noise because when it does turn on, it transmits the noise through the PEX and the wall just as the "regular" pump does.

And while yes, they are variable speed, it is my understanding that they have a minimum speed. And since the pumps are typically designed for larger systems, they end up not having to pump very much water in the TM before the cut-off pressure is reached and the pump turns off. The result: it still pulses on and off, albeit not as much as the regular pump.

But bottom line: IMHO, if you can isolate the regular pump to reduce the noise, the advantages of the variable speed pump become of little consequence.

Dave

[Wavery]

I used the 2G pressurized tank on my yacht. You couldn't even hear the pump run. My pump was twice he size of the TM pump (5.7G per minute) because I had 2 full baths with showers, sinks, outside shower and galley, all on the same pump.

Originally Posted by ShrimpBurrito

BTW - if you need to tie into PEX at some point and don't have a crimp tool, the Sharkbite connectors work perfect, as advertised. So far, no leaks.

Oh! Too late though, I've already forked out $35 for a crimping tool. Didn't need it for the flexible tubing install, but will for putting in a T for the tank.

Who knows it may be useful around the house too. All the plumbing I've done there is copper, but I'm getting tire of burning my fingers.