Community Forums

Tony Wilson · 06-09-2020, 12:57 PM

This is a 2018 Cornerstone. The pump makes too much noise and cycles frequently on even for a glass of water. It seems to be normal for this coach.

Have read several posts about installing absorbing material under pump and flexible lines in and out the pump to reduce vibration and noise.

I am also considering adding an acculation pressure tank.

I had a Dynasty with this extra tank and was a joy. I could flush toilet, wash hands without pump coming on.

What others owners have done? I am trying to anticipate issues like where to locate the tank, does your solution helped your issue? Thanks for sharing.

Tony

Ljwt330 · 06-09-2020, 01:15 PM

Quote:

Originally Posted by Tony Wilson

This is a 2018 Cornerstone. The pump makes too much noise and cycles frequently on even for a glass of water. It seems to be normal for this coach.

Have read several posts about installing absorbing material under pump and flexible lines in and out the pump to reduce vibration and noise.

I am also considering adding an acculation pressure tank.

I had a Dynasty with this extra tank and was a joy. I could flush toilet, wash hands without pump coming on.

What others owners have done? I am trying to anticipate issues like where to locate the tank, does your solution helped your issue? Thanks for sharing.

Tony

Without an accumulator, the pump running as soon as a faucet is turned on is typical. The fact that it cycles (or does it surge?) may indicate that the adjustment on the pressure switch is set incorrectly. This is the adjustment that determines when the pump will run when pressure begins to drop on the outlet side of the pump, and when it will shut-off.

I believe there is a pressure range of a few psi between when the switch closes (pump ON) and when it opens (pump OFF.) If the range is too narrow, the pump will switch ON/OFF instead of operating in a steady manner.

I have not had direct experience with your issue nor an accumulator, so I offer this information only to provide an explanation for your issue that may not require an accumulator. I don't know if your pump has an adjustment screw for the pressure switch, but others with similar pumps will know.

Old-Biscuit · 06-09-2020, 01:23 PM

Low flow......pumps can cycle

Insulation tubes placed around pump discharge line can help with the noise
Reloacting pump discharge line so it is NOT upagainst any surface (cabinet, wall etc) can help quiet pump
Computer mouse pad placed under pump can help.....just do not tighten pump feet screws down too much----just enough to secure pump

2 gallon accumulator tank on pump discharge side (any cold water line that is accessible/has room for tank) will help with pump short cycling

Short cycling of pump can also be due to 'adjustments' -----bypass system on pump not opening soon enough/pump start/stop pressure set points out of whack (typically 15psi difference between the two settings)

What Brand/Model is your pump???

LWBAZ · 06-09-2020, 01:24 PM

Tony, here is a link to what I did:

https://www.irv2.com/forums/f278/new...by-433673.html

Tony Wilson · 06-09-2020, 05:35 PM

Larry, --- Excelent description and solution. I like you photos. Thank you. When I go to the coach next time I will assess doing this project.
One question: Did you consider adding pressure tank? My thought is not having the pumping running so frequent, at night.

LWBAZ · 06-09-2020, 06:26 PM

Quote:

Originally Posted by Tony Wilson

Larry, --- Excelent description and solution. I like you photos. Thank you. When I go to the coach next time I will assess doing this project.
One question: Did you consider adding pressure tank? My thought is not having the pumping running so frequent, at night.

Tony, I've considered adding such a tank to several of the motorhomes we've owned, but have never been quite motivated enough to do it.

One of the issues is finding a good place to mount the tank, but I'm sure it's do-able. Here is a link to a short video which provides a good overview of adding an accumulator tank:

https://www.youtube.com/watch?v=BkPI-uFlrFA

oneknight · 06-10-2020, 05:54 AM

Most of the current RV water pumps are "bypass pumps"
They have an internal bypass valve, and 2 adjustment screws, 1 for max pressure and one for bypass pressure.

The intention is that at low flow, the internal bypass will open, and this will have the pump running continuously rather than cycling on and off.

The standard pump is a shurflo 4008. It draws 7.5 amps, and pump 3 gallons per minute @ 35 psi.

Many here have put in a Shurflo 4048. 15 amps, 4 GPM @ 55 psi. a LOT more pump.

I had multiple pump problems and many failures when I first got my Aspire, and resolved a lot of problems, my last pump has lasted a year and a half and counting, and of course I keep a ready spare that can be directly plugged in.

Changes:
Attached a piece of wood to metal wetbay panel, screwed pump to wood. Extended hoses with parts from Lowes. Pump is now easy to reach and much quieter.

G14 Breaker is 5 amps. Old pump labelled 7.5 amps. New one labelled 15! breaker would pop constantly with the 4048 pump. I wired in a relay, drawing power off the macerator line.

Pumps still failing! I found that the pump uses a small cherry microswitch rated @ .6 amps @ 125 volts. When the pump no longer makes any noise, this cherry switch has failed. It's under a cover where the wires go into the pump. This switch is available for less than a dollar, it was the problem in 4 failed pumps, all have been repaired. I then rewired the whole mess, using the cherry switch to control my relay, rather than it handling full pump current.

I have not had a pump failure in a year and a half.

brobox · 06-10-2020, 06:03 AM

I installed that same pumb the 4048 on my 14. It cycled all the time brand new. I had to adjust the pressure switch. That solved the problem and it wasn't that noisy. That same model is working fine on the 19. Sound like your pressure switch needs a simple adjustments. Several videos on YouTube, just need an allen wrench.