Forum Discussion

radiojeffrv's avatar
radiojeffrv
Explorer
Mar 01, 2018

water pressure

I have a Majestic 28A...when hooked to city water the pressure out of the faucets and shower are great! But when using the pump and fresh water tank the pressure starts great but quickly becomes very low. Is this a sign of a pump going bad or something else?
  • I am picking my coach up from the shop this morning after experiencing exactly the symptoms you have. A sharp mechanic realized when he moved the pump he got less flow into the filter screen by the pump. He undid the hose and followed it back, and a foot up the hose he found the line was kinked. He took the twist out of the hose and said it now works great.

    This is a new coach and I was not able to test the pump system because it never got above 20 degrees from when we took delivery until we headed south. If yours used to work you should see if your screen needs cleaning.

    Dave
  • Water pump is always going to have less pressure than shore water. How much drop is the issue. Check the filter screen on the water pump (new rigs sometimes get debris stuck in the filter (leftover crud from the water tank install). If the rigs new they take it to the dealer and have them check it out.
  • If the pressure starts good and then drops it not an issue with pump vs. shore (my coach I get better flow with the pumps on as I have 2 of them). You can disconnect the output hose of the pump and turn it on (point it outside or add a short hose). If the pump runs with plenty of flow, try blocking the outlet a bit to see if it still pumps well or the flow drops. If it drops you likely have a weak pump and it can be replaced or rebuilt. As mentioned you also want to check the filter screen if there is one and you want to check for any kinks in the line going from the tank to the pump. Even an old water line could collapse somewhat under suction. What kind of a pump is it and do you know at what pressure the pump is set? Does this happen at the sink as well as the shower when each is run separately?
  • Ivylog's avatar
    Ivylog
    Explorer III
    It's a 2012 Thor Majestic 28A so I would try what Bill suggests^^^^. I would clean the screen first.
  • 3X on the pump screen. When I picked up new RV the water pressure from the pump just didn't seem right. Took the filter apart and it was plugged up with small cuttings of the plastic line that the builders didn't bother to blow out during assembly. Cleaned out and Ok.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    I remember talking to Tommy Brandt (Country Gospel Singer) about his Prevost when he set up next to my mear Intruder (It was late due to a flat tire on his towed so I was providing work lights. I have LOTS of work lights)

    Noticed two water pump switches. ask him about it
    "With both of 'em on it'll knock your hat off in the shower"

    (I thought cowboys took their hats off for two things Shower and _____" (Smokey and the Bandit That was Bandit's line)

    Seriously. More likely a clogged outlet screen on the water tank or a`clogged inlet screen on the pump. (Outlet screen is optional depending on RV maker, I have one) This will restrict the pump's ability to pump. Also a pinched line, likely the inlet.

    If this was a house I'd suspet arterioSclerosis. (Had that on a hot water line in my Sticks and bricks.. A "Grafted" in a new artery (Pipe) and all was good.
  • High pressure when a tap is first opened and then quickly dropping is a sign of a line restriction. Look for a damaged pipe or partly closed valve.
  • beemerphile1 wrote:
    High pressure when a tap is first opened and then quickly dropping is a sign of a line restriction. Look for a damaged pipe or partly closed valve.


    It can also occasionally be a sign that the water heater was turned on and heated up its tankful, increasing the pressure in the system above nominal from the pump. At least, that's what it does in my RV.

    Generally, though, I'd agree with your assessment.
  • you can always put in a pressure tank . they work great with low pressure and pulsing pressure

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