Help with low water pressure

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HippieMamaRV

Member
Joined
Jan 23, 2022
Posts
7
Location
Cottonwood, Arizona
Hello. New to this website.. (If I am posting this in the wrong section, please let me know) I am desperately looking for help.

I have a 2005 Skyline Trail Blazer Toy Hauler- 5th wheel. My children and I have been living in it, fulltime, for about 9 months.. I am a bit of a do-it-yourselfer..
The current issue that I am having is an extreme lack of water pressure..
The water pressure from the kitchen sink, bathroom sink, and toilet are, as of this morning, less than pencil thin. The pressure has not always been this horrible.. When I first turn the sink on, the pressure is great for about 2-3 seconds and then it starts to slow.. within 6-7 seconds, there is barely any pressure.
I am hooked up to an rv hose, on my property. The hose has great pressure.(I do not have a pressure regulator, although I have ordered one on Amazon and waiting for it to arrive..)
Some recent repairs I have done:
  • Cleaned out my 6 gal Atwood water heater(changed old plastic drain plug with new, brass one, overnight soaked water heather with 3 gal Vinegar- topped off with water.. Sprayed out TONS of sediment. Soaked pressure relief valve in vinegar as well. Replaced old thermostat)
  • Installed new kitchen sink faucet.(Old one dripped and made hard water stains in sink..)
  • Fixed leak under kitchen sink, where water goes into water pump(pump is not used, as I use pressure from hose hook-up..)
  • Fixed leak under bathroom sink, twice. JUST TODAY-
  • Replaced water inlet valve{?}(where the hose screws into trailer)
  • Sprayed out water filter(Ordered new filters- Flow-Pur #8 cartridge..) Current filter is VERY green and slimy, so I sprayed it as much as possible.. will replace with new one when replacement arrives in a few days..
  • Checked and cleaned both sink aerator/filters.
  • -Tomorrow- I will replace old RV hose with new, clean one. I believe old one is causing green build-up in filter..?
NOTHING that I have done has helped with low water pressure issue.. Maybe even made it worse.. If I am missing something important, or doing something wrong, I am very willing to hear any advice to come my way!

Thanks so much!
Chelsie
 
One very important thing is remove that brass drain plug and install a new nylon plug. The plug being brass and the tank fitting being aluminum I believe are dissimilar metals and will cause a chemical reaction and possibly seize together and you probably won’t be able to remove it without causing damage to the threads of the tank.

As far as your pressure, did you change out the small screen washer where you connect the hose to? That fine mesh screen could be plugged up solid. They are available at and hardware store and Lowes. Don’t just remove it and install a rubber washer. You need the screen style.

Put water in your fresh water tank and try the pump. See if that fixes it.
 
Remove that filter completly and see if that restriction is causing the low flow. Only for the test, that will show if the filter is clogged.
 
(pump is not used, as I use pressure from hose hook-up..)

Does your 12v pump work ?
Yes. I thought I had a leak from the pump area, so I shut off the water going to it, as I was just using the pressure from my property's hose input anyway. However, I believe that I found the leak somewhere else and fixed it. I also emptied my fresh water tank. But I was planning to fill the tank and turn the pump on today and see if I have a normal pressure flow, using the 12v pump..
 
One very important thing is remove that brass drain plug and install a new nylon plug. The plug being brass and the tank fitting being aluminum I believe are dissimilar metals and will cause a chemical reaction and possibly seize together and you probably won’t be able to remove it without causing damage to the threads of the tank.

As far as your pressure, did you change out the small screen washer where you connect the hose to? That fine mesh screen could be plugged up solid. They are available at and hardware store and Lowes. Don’t just remove it and install a rubber washer. You need the screen style.

Put water in your fresh water tank and try the pump. See if that fixes it.
I will look more into that information on the plug. Thank you!
I replaced the whole part where you connect the hose outside. I was assuming that it was plugged up as well. When I took the old piece off, there wasn't even a mesh screen, just the plastic check valve. It was a little clogged so I was excited, thinking it would definitely help the water flow improve.. However it did not. The new piece has a mesh screen on it..
I will try the tank today.
Thank you. :)
 
Yes. I thought I had a leak from the pump area, so I shut off the water going to it, as I was just using the pressure from my property's hose input anyway. However, I believe that I found the leak somewhere else and fixed it. I also emptied my fresh water tank. But I was planning to fill the tank and turn the pump on today and see if I have a normal pressure flow, using the 12v pump..
You have a shut-off valve between your fresh water tank and 12 volt pump ?
 
I won't bother with comments on Bypass or Hot water system other than to agree..
Since your problems are with both COLD and HOT this indicates those are good advice but NOT your problem So I'll cover two different paths

City water
Make sure there is pressure incoming (See link) NOTE there is a "Regulator" that looks almost exactly like this gauge.. If you look "Down the pipe" on this gauge.. there is nothing inside it. The regulators that resemble it (you can not see through the pipe) are junk avoid them.

IF the park has like 10 PSI problem found
Now make sure your hose is not kinked or "Sat on" (Parked on?) That will shut it down too.
Now there is an inlet on the RV, there is a screen.. Inspect visually
Behind it is a check valve.. I seriously doubt it's a problem but .. it could be.
Then you get into the water system. Anywhere there is plubming in a slide out pinched lines... Possible.


HOUSE water (Tanked water) There is often an "outlet strainer" inside the tank, it can "Slime up" and not pass (Oh and the tank can be empty)
Then the line to the pump can be pinched or a valve in that line closed, or a drain valve opened.
The pump.. might not be good
Pinched lines post pump.

NOTE in the case of pinched lines or clogged strainers when you FIRST open a valve you normally will have good flow.. then slows like it's running out of pressure (exactly what is happening)

If you have a regulator in line that looks like the pressure gauge.. That's your problem Junk it and get a Valterra adjustable or .. Well I used zurin or Watts 3/4 Inch with adapters.
 
Since both hot & cold have low flow, the water heater bypass valves are not the source of this problem.

There are two very likely culprits:
  1. The debris screen at the city water hose inlet is clogged or damaged, reducing flow through it
  2. Your water filter is full of the stuff it has been filtering - get a new one. In the meantime, remove it.
 
On my RV the city feed goes through the pump even though it's shut off. My pump also has an inlet screen and every season I clean crud out of it. Just suggesting another potential single restriction point.

Mark B.
Albuquerque, NM
 
Sprayed out water filter(Ordered new filters- Flow-Pur #8 cartridge..) Current filter is VERY green and slimy, so I sprayed it as much as possible.. will replace with new one when replacement arrives in a few days..
As others have said, you should remove that filter until you can get a new one.
  • Checked and cleaned both sink aerator/filters.
  • -Tomorrow- I will replace old RV hose with new, clean one. I believe old one is causing green build-up in filter..?
The green that you describe sounds like you have algae in the system and since it was in the hose and the water filter, it is probably all through the entire water system. Even if you do manage to get pressure back, it will return fairly soon if you do not kill it completely. The best way to do that is to do a completer water system sterilization.
 
Simple first thing. Remove screens on faucets and clean them. Likely when you cleaned out the water heater you sent a bunch of scale through the lines and that is blocking the faucet outlets.
 
Thank you to everyone who replied! I took out the filter from the housing and my water pressure is back to normal. I wasn't aware that I could remove the filter. Also, I didn't know that a dirty filter could effect the water pressure so drastically. At least all of my filters/screens have had their bi-annual cleaning. I will be better about keeping up on filter changes.. And I will be looking into sanitizing my whole water system.
Incredible support here! Thanks again.
Chelsie.
 
I'll mention one other possibility even though it isn't real likely. A friend had the same problem with very low pressure on the hot and cold water everywhere in his trailer. I checked most of the things mentioned above and finally decided to disconnect the the water hose from the trailer and see what flow I would get out of the unconnected hose. What I noticed right away was that the rubber washer in the city water connection was smashed and the hole in the washer was close at least half way. I checked the washers at the inline filter and at the campsite faucet and they were all smashed enough to reduce the hole size in the washers. He must have really put the muscle on those connections. Changing all the hose, filter and connection washers fixed his problem.

Had we put water in the freshwater tank and tried the pump the pressure would have been fine and that would have led us sooner to the hose connections.
 
And I will be looking into sanitizing my whole water system.
Do that part before you install the new filter and after you get the new water supply hose. An easy way to add the chlorine bleach to the system is to add the bleach into the filter housing, leaving the filter cartridge out until you have finished the entire process. You may need to flush more than once to get all of the algae out of the plumbing inside of the RV but the chlorine bleach will kill the algae.
 
That was exactly my plan of approach. However, my question is, how do I bleach the section from the city water inlet to the filter housing? The water does not flow backwards, correct?
 
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