Water pump backflow issue?

[Bechard]

Hi guys, this weekend my fresh tank was being filled when I was connected to City water at the campground we were visiting. Hooked everything up, left for groceries, and came back to find water spitting out of the fresh water tank's air vent.

Trailer is a 2018 Keystone Bullet Crossfire with Flojet pump.

Fortunately no water leaking anywhere inside, but I did have to spend the first two hours of my trip fixing the water issue. I couldn't find the backflow valve between the pump and the pressurized side. Originally there was a plastic tee connecting the pump and city water to the inside water line.

I ended up replacing the tee with a brass winterizing three way valve, which allowed me to simply turn off the inlet from the pump, and let me switch between city and pump with the new valve. Between the parts to make everything connected, it's extremely tight trying to plug the pump outlet quick fitting back in. I was planning on simply unscrewing the pump from the floor, sitting it on top of some vibration and noise eliminating foam, and screwing it back down two inches closer where I can slip the outlet fitting in without worrying about kinking the water line.

Does this sound reasonable, and should the pump work fine in a few weeks when I need to use it without a city water connection? I'm going to try this tonight, but the pump does pump water, it was just cycling on every 30 seconds since it was getting air from the city water connection (I believe).

Anything else I need to look at?

[Bechard]

Here are a few photos from before I added the brass valve in place of the plastic tee. The top of that tee is where the city water line screws on. The black quick connect is the out line of the pump.2189521896

[Bechard]

Just an update, I ended up biting the bullet and just towed an hour to the dealership under warranty. The RV service manager believes my issue is the backflow membrane in the pump. They are going to take care of it and have my trailer ready for pickup on Saturday.

Do people normally keep spares?

[bobbecky]

Regardless whether they are fixing or replacing the pump, have them install a strainer ahead of the pump to prevent crud from getting into the pump and check valve. It will save you in the future. https://www.amazon.com/SHURFLO-255-313-Twist-Pipe-Strainer/dp/B000V2W0GE/ref=sr_1_2?keywords=shurflo+water+pump+screen&qid=1558482689&s=gateway&sr=8-2

[LHaven]

I was planning on simply unscrewing the pump from the floor, sitting it on top of some vibration and noise eliminating foam, and screwing it back down

A wise man once told me that most of the objectionable noise from the pump is transmitted through the piping, not the floor. I don't remember the brand name, but there's a line of "acoustically softer" piping we put on the pump in our previous rig and it made a world of difference.

[bobbecky]

It's a Shurflo Silencing kit. https://www.amazon.com/SHURFLO-94-591-01-Pump-Silencing-Kit/dp/B000WN5F96

[LHaven]

Now if I only knew if I had a Shurflo pump, and how to access it...!

[Bechard]

Regardless whether they are fixing or replacing the pump, have them install a strainer ahead of the pump to prevent crud from getting into the pump and check valve. It will save you in the future. https://www.amazon.com/SHURFLO-255-313-Twist-Pipe-Strainer/dp/B000V2W0GE/ref=sr_1_2?keywords=shurflo+water+pump+screen&qid=1558482689&s=gateway&sr=8-2

Thanks, I'll ask them about this today.

[Bechard]

A wise man once told me that most of the objectionable noise from the pump is transmitted through the piping, not the floor. I don't remember the brand name, but there's a line of "acoustically softer" piping we put on the pump in our previous rig and it made a world of difference.

I'm starting to wonder if wrapping the water lines in pipe insulation for 2" where it goes through any panels would help. I've also read of people mounting the pump on top of a mouse pad to further insulate.

[JRTJH]

A mouse pad or a piece of "semi-rigid foam" will help a bit, but there are 4 mounting screws that hold the pump to the floor (or wall) of the trailer. Sound and vibrations are transferred through that mounting system in spite of the 4 rubber "insulation feet" that both ShurFlo and FloJet use.

Insulating the pump beyond the "standard installation" will help as will eliminating any locations where pipes rest against the trailer structure. Essentially, any place where the cold water lines rest against a structure in the trailer will transmit the vibrations from the pump to the structure. That's very much the same as "beating a drum" and magnifies the noise.

I built a "insulating mount" for my pump, installed that, isolated all the PEX lines that run through walls/cupboards and also covered the pump with some "sound insulation" that I removed from an old dishwasher. It's all "helpful" but trust me when I say, "You'll still hear your pump when it turns on, especially at night, when it's quiet. Hoping for "silence" is only a pipe dream when it comes to 12 VDC water pumps in a "built to be light enough for half ton towing" RV.

[busterbrown]

I'm starting to wonder if wrapping the water lines in pipe insulation for 2" where it goes through any panels would help. I've also read of people mounting the pump on top of a mouse pad to further insulate.

This is what I did to my Bullet. First order was to replace the loud OEM pump.

http://www.keystoneforums.com/forums/showpost.php?p=242443&postcount=68

[GMcKenzie]

It's all "helpful" but trust me when I say, "You'll still hear your pump when it turns on, especially at night, when it's quiet. Hoping for "silence" is only a pipe dream when it comes to 12 VDC water pumps in a "built to be light enough for half ton towing" RV.

Biggest reason I put in an accumulator tank. Our pump is on DW's side of the bed. I'm the one who gets up 2-3 times a night. So flushing the toilet would wake her up. With the tank, we can turn the pump off and still have enough water for flushing.

[FlyingAroundRV]

The RV service manager believes my issue is the backflow membrane in the pump.

Yes, that sounds right to me. All water pumps have a non return valve in them. That is how they maintain the pressure in the lines when the pump is off and that pressure is used to turn the pump off. Also, that non return valve stops the city water from flowing backwards through the pump into the FW tank. There should also be a non return valve between the city water inlet and the pump outlet so that when the pump is operating it doesn't pump water out of the city water inlet.

[Bechard]

I just heard back from the dealership and hour ago. The service manager did confirm that the pump was defective as the backflow wasn't working. They swapped the pump out for a new one under warranty, and adjusted two sticking cabinet doors for me.

Back to the camping season!

[apachewolf]

Just an update, I ended up biting the bullet and just towed an hour to the dealership under warranty. The RV service manager believes my issue is the backflow membrane in the pump. They are going to take care of it and have my trailer ready for pickup on Saturday.

Do people normally keep spares?

I have had 3 pumps replaced (Shureflow) and finally told the dealer to install a brass check valve at the pump. We''ll see how that works.

Happy camping.:)