Almost zero water pressure

johndjmix · 09-08-2021, 08:00 PM

Hey Guys, so im out here in Oklahoma this week. Heres the issue....

Yesterday everything was normal, full water pressure, but today it seems like there is very little water getting to the pump. When i turn on the water i just get a drizzle, and when i turn it off the pump runs for around 20 seconds...then achieves the pressure it wants and turns off.

No way the filter clogged 100% in 8 hours....the tank fill valve is in the correct position, and there are no leaks.

When hooked up to shore water, no issues...full pressure from the shore water supply.

Pretty obvious there is a clog or something closed going to the intake of the pump. The strainer on the pump is clean, checked that.

Where does the intake hose into the pump come from? I need to know the plumbing of from the pump to the tank.

--John

MoJoe1003 · 09-08-2021, 08:24 PM

There’s a black check valve in there somewhere. I had one fail. Try to find that check valve and that may be your issue. Just a guess.

camper_Lucy · 09-08-2021, 08:30 PM

depending on your unit you have, the line feeding the pump is direct from your fresh water tank (may have a valve and feed for Antifreeze - model dependent). Generally low water pressure from the pump is either air getting into the line before the pump or blockage. Based on your note there was nothing in filter so highly unlikely a blockage from matter in the line. I would check for cracks or kinks in the feed line as a crack would let in the air or a kink would reduce flow to the pump. lastly are you sure there is enough water in the fresh water tank, low water level would also let in air?

camper_Lucy · 09-08-2021, 08:33 PM

Quote:

Originally Posted by MoJoe1003

There’s a black check valve in there somewhere. I had one fail. Try to find that check valve and that may be your issue. Just a guess.

Black check valve is on the city water side of the pump, poster stated city hook up pressure was good and if the black valve failed he have low pressure on city side too.

johndjmix · 09-08-2021, 10:01 PM

Yes, city hookup is good.

The tank fill/city water valve in the compartment must be in line before the pump, because every time I put it to “tank fill” the pump runs non stop.

—john

Cactus Canyon · 09-09-2021, 06:44 AM

I had the same problem a couple of years ago. Luckily I was close to the dealer and they were able to look at it right away.
They told me that the fresh water tank shifted, and that pinched the tubing leading out of the tank. They anchored the tank in the right position and replaced the tubing.
I’m no expert, but that’s what they said.

MoJoe1003 · 09-09-2021, 07:01 AM

Quote:

Originally Posted by camper_Lucy

Black check valve is on the city water side of the pump, poster stated city hook up pressure was good and if the black valve failed he have low pressure on city side too.

You’re right. I couldn’t remember exactly. It has been a while since it failed. Thanks for the reminder!

Larry-NC · 09-09-2021, 03:59 PM

One possibility is that the "winterization valve" has moved from the closed position to partially open.

This valve controls where the water pump draws from, selecting between the fresh water tank and a short hose you dip into a bottle of potable RV antifreeze. If that valve has moved a little, so it's between the two positions, it will suck a lot of air through the open antifreeze hose and a little water from the fresh water tank.

Not exactly how it's structured on a Dynamax, but it's got to be there someplace. You southwestern folks may have never used it.

johndjmix · 09-09-2021, 04:10 PM

Cactus Canyon, you win the beer. Do you have anything to do with the cactus canyon bar up in Greeley, CO?

I took the panels off under the wardrobe to get to the tank. Funny, in the past i asked about getting to that tank because i knew one day i would have to.

FYI, the panels can be popped out easily by screwing in a sheet metal screw near the bottom and pulling gently and wiggling the panel to remove. You DO NOT need to remove the "trim" 4" sections of wood that go vertically, each pannel can be removed without touching them as they are fit in between (Thanks Dynamax!).

There is a metal structure to hold the tank from moving side to side, but not front to back. It slid forward, bending the pex causing the blockage (see pics).

Now, the issue is it also crimped the drain line, so how do i empty it to slide it back....well, very slowing. Its flowing...ill let it go all day and it should be light enough to slide back. Im going to screw a block of 2x4 in front of it to stop it from sliding again.

Im not sure how i can get that straping screwed back in without removing the tank. Wouldnt be the end of the world, but dont want to have to do that.

--John

Quote:

Originally Posted by Cactus Canyon

I had the same problem a couple of years ago. Luckily I was close to the dealer and they were able to look at it right away.
They told me that the fresh water tank shifted, and that pinched the tubing leading out of the tank. They anchored the tank in the right position and replaced the tubing.
I’m no expert, but that’s what they said.

**bclemens** · 09-09-2021, 06:39 PM

As a side note, pex lines can normally be heated back to their original shape (gently). However it is easy to screw that up and just cutting the line and replacing that section might be easier.

Cactus Canyon · 09-09-2021, 06:42 PM

Glad to be able to help.
No relation to the bar, but will have to go there. My wife owns Cactus Canyon Jewelry in San Antonio.

johndjmix · 09-10-2021, 12:16 AM

Didnt have the tools to heat it, so i just straightened and gently squeezed with a plyers. Its back to normal shape. PEX is very durable...not worried about it.

Brian, might want to add a block of wood in front of the tank to stop this from happening. Very cheap to do! The strapping with just one screw in the end wont hold in some situations ( Heavy braking over bumps ).

Im convinced what did it was when i was pulling into this town...back country road going about 50, all of sudden 3 rail road track crossings and a bit of a drop. I braked hard and hit the rough tracks as i was braking. It worked an hour before, so im convenced thats what did it.

Quote:

Originally Posted by bclemens

As a side note, pex lines can normally be heated back to their original shape (gently). However it is easy to screw that up and just cutting the line and replacing that section might be easier.

**bclemens** · 09-10-2021, 07:57 AM

Quote:

Originally Posted by johndjmix

Didnt have the tools to heat it, so i just straightened and gently squeezed with a plyers. Its back to normal shape. PEX is very durable...not worried about it.

Brian, might want to add a block of wood in front of the tank to stop this from happening. Very cheap to do! The strapping with just one screw in the end wont hold in some situations ( Heavy braking over bumps ).

Im convinced what did it was when i was pulling into this town...back country road going about 50, all of sudden 3 rail road track crossings and a bit of a drop. I braked hard and hit the rough tracks as i was braking. It worked an hour before, so im convenced thats what did it.

Totally different installation today.

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