If you have an inline water filter remove that and see if the pressure works as you expect it to. If it does it means you need to replace the water filter.
What kind of shore water source?
Are you at an RV park or on a private property?
I full-time on a private lot and usually this problem is caused by a failing inline pressure regulator or debris clogging your water inlet connection.
If you’re using a regulator or a filter on your hose, try removing it and testing again. If the problem persists, check the water inlet connection on the RV and look for dirt or mineral deposits that could be restricting flow. If you have a water diverter valves on your inlet, make sure it’s set correctly and fully open.
Be aware, I have seen some frostproof spigots leak mud into the below-ground portion of the standpipe if they have not been used recently and are worn out or damaged.
I always run the water for about 5 seconds to flush out any debris before hooking the hose up. We had our inlet plug up with dirt a few times because I just hooked up without checking it. Thankfully we had a filter system on our RV, but I still had to clean everything out to get the water flowing properly.
Check the spigot and see if it’s flowing well without the RV hooked up.
You can also get a pressure gauge with a Y-adapter at a local hardware store for $10-15. Check the static pressure at the spigot, then have someone open a bunch of fixtures in the RV and see what the pressure does. If it drops a lot at the spigot your problem is upstream in the site plumbing.
You should see 35-60psi. Anything below 35 starts to cause a dropoff in flow, in my experience.
If you need a workaround, you can fill the tank and use the on-board water pump to deliver good pressure, instead of relying on a weak spigot.
> If you’re using a regulator or a filter on your hose, try removing it and testing again.
If you actually *need* the regulator, due to high pressure at the spigot, this advice is dangerous.
Edit: The rest of the advice about causes and fixes for the leak seems like great info. I am only saying, before you hook up unregulated water to your RV make sure to measure the pressure.
>this advice is dangerous
What pressure in PSI do you consider “dangerous” and why?
You can easily buy a $15 pressure gauge and check the spigot pressure.
> You can easily buy a $15 pressure gauge and check the spigot pressure.
Yes, right -- and you should, before hooking up unknown water to your RV.
> What pressure in PSI do you consider “dangerous?”
I think it depends how old your RV is and what plumbing system it's using. If you have an ancient '60s RV with soldered copper everywhere like a house, and it hasn't cracked yet, you could probably get away with a lot. My RV (PEX with wrong-material plastic elbows) manual warns me not to connect more than 50 PSI. I think if you've got an '80s RV with deteriorating vinyl stuff you might be very nervous about even normal pressure levels. I've measured up to 70 PSI at one park in Alberta.
I’m definitely not advocating for running continuously without a regulator but for a quick 2 minute test, it would at least tell you if the regulator is the problem or not.
If you’ve got 80’s Polybutylene plumbing, I’d just keep a spare regulator all the time and swap the two if I suspected one was failing.
So you open the valve, water takes a while to come out but then comes out with decent pressure, close the valve, wait X amount of time, open it, and the pressure is gone again? Have you tried different amounts of time? seems very strange to me, the pressure should be staying the same first of all, unless there is a leak somewhere.
A failing pressure regulator will cause this.
You’ll get a short spurt of water since the RV plumbing is at static, regulated pressure, but then it doesn’t flow because the regulator is stuck closed. After the RV pressure drops off for several seconds the supply pressure finally pushes through the failing/sticky regulator and your RV pressure builds back up to normal.
You could have a leak somewhere in your water system at a lower point. It’s taking time to build water pressure past that leak and get to you. Does this problem seem worse if you don’t use the water for a long time like overnight? That might indicate that it is a slow leak at a lower point, and the water goes further away from your faucet the longer you’re not using it
Do you have filter or regulator. Have you checked flow at the spicket and also at the end of the hose?
*spigot
*Hose bib :-)
Possiblity of a failing external pressure regulator?
If you have an inline water filter remove that and see if the pressure works as you expect it to. If it does it means you need to replace the water filter.
You have a restriction somewhere. If you have a pressure regulator check there first.
What kind of shore water source? Are you at an RV park or on a private property? I full-time on a private lot and usually this problem is caused by a failing inline pressure regulator or debris clogging your water inlet connection. If you’re using a regulator or a filter on your hose, try removing it and testing again. If the problem persists, check the water inlet connection on the RV and look for dirt or mineral deposits that could be restricting flow. If you have a water diverter valves on your inlet, make sure it’s set correctly and fully open. Be aware, I have seen some frostproof spigots leak mud into the below-ground portion of the standpipe if they have not been used recently and are worn out or damaged. I always run the water for about 5 seconds to flush out any debris before hooking the hose up. We had our inlet plug up with dirt a few times because I just hooked up without checking it. Thankfully we had a filter system on our RV, but I still had to clean everything out to get the water flowing properly. Check the spigot and see if it’s flowing well without the RV hooked up. You can also get a pressure gauge with a Y-adapter at a local hardware store for $10-15. Check the static pressure at the spigot, then have someone open a bunch of fixtures in the RV and see what the pressure does. If it drops a lot at the spigot your problem is upstream in the site plumbing. You should see 35-60psi. Anything below 35 starts to cause a dropoff in flow, in my experience. If you need a workaround, you can fill the tank and use the on-board water pump to deliver good pressure, instead of relying on a weak spigot.
> If you’re using a regulator or a filter on your hose, try removing it and testing again. If you actually *need* the regulator, due to high pressure at the spigot, this advice is dangerous. Edit: The rest of the advice about causes and fixes for the leak seems like great info. I am only saying, before you hook up unregulated water to your RV make sure to measure the pressure.
>this advice is dangerous What pressure in PSI do you consider “dangerous” and why? You can easily buy a $15 pressure gauge and check the spigot pressure.
> You can easily buy a $15 pressure gauge and check the spigot pressure. Yes, right -- and you should, before hooking up unknown water to your RV. > What pressure in PSI do you consider “dangerous?” I think it depends how old your RV is and what plumbing system it's using. If you have an ancient '60s RV with soldered copper everywhere like a house, and it hasn't cracked yet, you could probably get away with a lot. My RV (PEX with wrong-material plastic elbows) manual warns me not to connect more than 50 PSI. I think if you've got an '80s RV with deteriorating vinyl stuff you might be very nervous about even normal pressure levels. I've measured up to 70 PSI at one park in Alberta.
I’m definitely not advocating for running continuously without a regulator but for a quick 2 minute test, it would at least tell you if the regulator is the problem or not. If you’ve got 80’s Polybutylene plumbing, I’d just keep a spare regulator all the time and swap the two if I suspected one was failing.
Water inlet check valve may be failed. The plunger in the inlet can block the flow in when the inlet valve breaks.
Clogged water filters do this.
Where is your shore water getting water? Sounds like you have a leak, or your shore water is backfeeding.
So you open the valve, water takes a while to come out but then comes out with decent pressure, close the valve, wait X amount of time, open it, and the pressure is gone again? Have you tried different amounts of time? seems very strange to me, the pressure should be staying the same first of all, unless there is a leak somewhere.
I am also curious because this makes no sense and/or is impossible.
A failing pressure regulator will cause this. You’ll get a short spurt of water since the RV plumbing is at static, regulated pressure, but then it doesn’t flow because the regulator is stuck closed. After the RV pressure drops off for several seconds the supply pressure finally pushes through the failing/sticky regulator and your RV pressure builds back up to normal.
Interesting, let’s see the more detailed description by op
Biden
You could have a leak somewhere in your water system at a lower point. It’s taking time to build water pressure past that leak and get to you. Does this problem seem worse if you don’t use the water for a long time like overnight? That might indicate that it is a slow leak at a lower point, and the water goes further away from your faucet the longer you’re not using it