Forum Discussion

jpmyers's avatar
jpmyers
Explorer
Oct 17, 2020

Fresh Water Pump

The park we are in has "amenities" that are less than desireable. The water pressure on a good day will be around 40psi. Frequently it will be 20psi or less. I've read as low as 12psi for a sustained period of 6-8 hours.

I had the brilliant idea of filling my fresh tank and using the onboard pump to supplement park pressure. That seemed to work well but for one issue. The rotary pump has begun sounding like a diaphram pump. So as I am investigating this issue, I find a valve between the bypass and the pump inlet. Attached to a side port of this valve is a hose that runs out a few feet and is open ended. A few youtube videos later I decide this is to prime the pump so I try primimng the pump. The pump is suddenly running quiet with little more than the sound of the electric motor and the water it's pushing through the lines.

I think I've got this one figured out until half an hour later. I'm on this site researching fresh water issues when I see water creeping across the floor. So NOW I know which way that 3-Way Valve has to be positioned! I'm back to the diaphram sound now but the floors are dry again.

WHAT is making my pump sound like that? I will only use it when I have to as it causes the water to pulsate from whichever faucet is being used. But still, I need to be able to use this rig without it sounding like a continuous water hammer event.
Seeking Advice
  • down_home's avatar
    down_home
    Explorer II
    Nov 03, 2020
    Provost chassis have or at least the few I've seen have an impeller pump like our well pump at last home.I started to look into changing ours to such, as I think there is plenty of room. Power I'm not sure. But got distracted and let it go.
  • jpmyers's avatar
    jpmyers
    Explorer
    Nov 03, 2020
    Ours is a PENTAIR SHURFLO 4008-101-A65 which is indeed a four chamber diaphram pump. And it is a noisey little bugger. I've found a few videos explaining troubleshooting and rebiulding of these pumps. Now I can get back to some of the other bumerous issues we're having with this rig.

    Thanks All for the tips and pointers.
  • 4x4van's avatar
    4x4van
    Explorer III
    Oct 29, 2020
    I've never seen a rotary water pump on an RV (could be mistaken). They are all diaphram pumps, as far as I know. However, they can be quite loud, or they can be reasonably quiet, depending on the model, the mounting, the location, and the water lines immediately adjacent to the pump.
  • jpmyers's avatar
    jpmyers
    Explorer
    Oct 18, 2020
    Valhalla360, The water on the floor was coming from the Antifreeez line Cavie mentioned. This was due to me having the 3-Way valve in the wrong position.

    I need to take the cabinet apart again. I should have snapped a photo of the pump label while I was in there yesterday. If it is indeed a diaphram pump, I will start looking for a rotary pump. There is no reason to have to listen to that noise in anything that cost as much as this. I could very well be wrong again, but I can't imagine sitting in a Prevost and having to endure this noise. Not to mention the cavitation of the water pressure!
  • down_home's avatar
    down_home
    Explorer II
    Oct 18, 2020
    The pump that came on our Mh an Aquajet, with switch on, would kick in if the city water pressure was below the 55psi5gph, stayed off if 55 psi or above, of the pump.
    We had to replace it with same pump supposedly, while in Fla in 14,doesn't seem to do that. Low water pressure we usually, anyway, fill the tank in the evening and then use from it. Too bad there aren't valve controls inside.
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Oct 18, 2020
    We routinely turn on our onboard pump to augment low park pressure from our fresh tank for showers with no problems. I am curious about the make/model of the OP's pump though.
  • cavie's avatar
    cavie
    Explorer
    Oct 18, 2020
    the line is for Anti freeze. Not priming the pump. As stated above Fill the tank and use just the pump. turn ogg the city water.
  • valhalla360's avatar
    valhalla360
    Navigator
    Oct 17, 2020
    Typical RV water pumps are diaphragm pumps. They are self priming.

    Another issue is once your onboard water tank is empty, they just attempt to push air.

    Find out where the water creeping across the floor is coming from. Nothing you did should have caused that but it can destroy your RV quick.
  • SAR_Tracker's avatar
    SAR_Tracker
    Explorer
    Oct 17, 2020
    Fisherman wrote:
    Fill the fresh water tank and use the pump alone.



    This^^^^^^^^^^^^^^^^^^^^^^^^
  • Fisherman's avatar
    Fisherman
    Explorer
    Oct 17, 2020
    Well think about your brilliant idea for a moment. You have park water coming in and the fresh water tank pump fighting with pressure already in the pipes, something has to give sooner or later. Why not fill the fresh water tank and use the pump alone.

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