Water pump keeps running

[cbearl78]

Hi, new guy here. I have a 2021 NoBo 19.6 and having issues with the water pump where it runs continuously with no pressure. I also have the problem with the city water overflowing the tank, so I cycled the pump thinking it was the check valve. That did not solve the problem so now I'm thinking I need to install an external check valve, but wondering if I should check the pressure output first? I consulted the dealer service department and they think the whole pump may be bad, but that may be an excuse for them to sell me a new pump. Any suggestions highly appreciated.

[aceinspp]

If you had no issues prior to this time then it most likely is the check valve is stuck. Need to cycle city water on and turn pump on then turn city water off and water pump. Cycle water pump again make sure there is water in fresh water tank. Later RJD

[ggrimm01]

Hello

Sound like you may have lost prime or the pump portion is bad. I replaced a pump and could not get primed through the fresh water. I got primed by using the rv antifreeze port. Did you say using your city hookup fills your freshwater? If so your check valve may be stuck or bad.

Goodluck

[cbearl78]

Originally Posted by aceinspp

If you had no issues prior to this time then it most likely is the check valve is stuck. Need to cycle city water on and turn pump on then turn city water off and water pump. Cycle water pump again make sure there is water in fresh water tank. Later RJD

I tried cycling by pressurizing with city water but turned it off before turning on the pump. I thought it was bad practice to run the pump with city water pressure? I can try this method but how long is it safe to run the pump while under city water pressure?

I had filled the fresh water tank prior to using, plus the backflow from city water no doubt topped it off

[Reverse_snowbird]

Unfortunately, this has come up before on many different types of rvs.

This is a slightly different version of the post above.
To stop water pump from slowly filling fresh water tank while connected to city water:
1. Shut off city water
2. Open faucet until water stops running
3. Shut off faucet
4. Turn on water pump, 
open faucet and run water for a minute
5. Shut off faucet
6. When pump stops running, turn off pump
7. Turn on city water
8. This procedure will reseat the water pump back flow valve. Remember: Do not run pump when city water on.

Worked for a friend. If that doesn't help, you're going to have to do more troubleshooting.

[cbearl78]

Originally Posted by Reverse_snowbird

Unfortunately, this has come up before on many different types of rvs.

This is a slightly different version of the post above.
To stop water pump from slowly filling fresh water tank while connected to city water:
1. Shut off city water
2. Open faucet until water stops running
3. Shut off faucet
4. Turn on water pump, 
open faucet and run water for a minute
5. Shut off faucet
6. When pump stops running, turn off pump
7. Turn on city water
8. This procedure will reseat the water pump back flow valve. Remember: Do not run pump when city water on.

Worked for a friend. If that doesn't help, you're going to have to do more troubleshooting.

Thanks, this is exactly what I tried after seeing it in another thread. Unfortunately at Step #4 water does not flow (no apparent pressure), and the pump just keeps running even after all faucets are closed.

[Giboneys]

If you have a Shower Mizer make sure it's turned the correct way.

[5picker]

Have you tried removing the line from the output side of the pump and see if it is trying to pump water? Is there water in the suction/strainer bowl? And as mentioned, check the Showermiser if equipped.

It's possible your pump head is bad and won't pump and also allowing backflow into the fresh tank. Before I threw a pump at it, I'd be pulling it apart and see what's going on but that's me and maybe you are not that inclined to tear it apart.

[cbearl78]

Originally Posted by Giboneys

If you have a Shower Mizer make sure it's turned the correct way.

Thanks, I'll check that

[Larry-NC]

Originally Posted by 5picker

Have you tried removing the line from the output side of the pump and see if it is trying to pump water? Is there water in the suction/strainer bowl? And as mentioned, check the Showermiser if equipped.

It's possible your pump head is bad and won't pump and also allowing backflow into the fresh tank. Before I threw a pump at it, I'd be pulling it apart and see what's going on but that's me and maybe you are not that inclined to tear it apart.

Most of the posts in this thread seem to assume that there are only two things to do: change the check valve or change the "bad" pump. There are other options.
The following is a simplified discussion.
The water pump, like that in a consumer-grade pressure washer, has three or five pistons, each actuated in sequence by a rotating cam element. Each of the pistons actuates a rubber diaphragm.

The diaphragm acts like a separate check valve for each piston/cylinder. If any one of those pistons sticks, pressure seeps back and no pressure builds up in the line. It's reported to be easy to take the pump apart and replace needed parts. The diaphragm is sold as the "Valve assembly" for $16-20. The piston and cam "Drive assembly" is also sold separately, as is the entire pump head assembly. Here's the first source I found: https://pantherrvproducts.com/shurfl...rts-breakdown/ It might not be the cheapest.

[TitanMike]

Don't overlook the fact most rv pumps today have a "bypass" feature and misadjustment of both pressur switch and bypass setting can cause pump to run perpetually.

Pump mfr's usually have adjustment procedures posted on their websites so check using the actual pump's model number.

[cbearl78]

Thanks to everyone for the great feedback. It took me a while to get back to troubleshooting this, but I think I found the problem. When I accessed the pump I saw that the top of the cap that secures the inline filter was sheared off, so there was a constant supply of air in the system.

I asked the service department at my dealer if they might have any left over from a repair, and lucked out that they had one. I'll post an update if this doesn't fix the problem.

Here's a shot of the cap inline and a closeup:

[Larry-NC]

Many people remove the internal filter and just use a hose filter for both city water and filling the fresh water tank.

[5picker]

Originally Posted by cbearl78

Thanks to everyone for the great feedback. It took me a while to get back to troubleshooting this, but I think I found the problem. When I accessed the pump I saw that the top of the cap that secures the inline filter was sheared off, so there was a constant supply of air in the system.

I asked the service department at my dealer if they might have any left over from a repair, and lucked out that they had one. I'll post an update if this doesn't fix the problem.

Here's a shot of the cap inline and a closeup:

That looks like it had water in it and froze at some point and broke the cap. I've seen about 10 similar to that one.

People blow out with air but forget air doesn't address water in the pump or suction-strainer.

[Bob K4TAX]

Yep. I found ours to have a cracked plastic cover on the pump intake line. Using the low point drains DID NOT remove the water from the filter, nor does draining the fresh water tank. This issue was from the previous owner who just dumped the low-point drains.

There are many ways to winterize a system. Some use antifreeze, some use air and blow out the system, and others go about it helter-skelter.

Choose your method but in many cases, one needs to inspect everything to assure no water is found anywhere.

Bob

[MNtraveler]

Originally Posted by Larry-NC

Many people remove the internal filter and just use a hose filter for both city water and filling the fresh water tank.

That’s actually the small filter ahead of the water pump that is necessary to protect it. It’s not the main internal water filter that filters city water as well as fresh tank/pumped water.

[cbearl78]

Originally Posted by 5picker

That looks like it had water in it and froze at some point and broke the cap. I've seen about 10 similar to that one.

People blow out with air but forget air doesn't address water in the pump or suction-strainer.

Interesting. I consulted with my dealer service department about winterizing when I first got the trailer, and they said there was no need to do anything because of where we live (Pacific Northwest, west of the Cascades) I usually drain the tank just to be safe but see now that it's not enough.

One of the reasons I bought this model is that it's fully winterized and I plan to do some cold-weather camping with it. Hate to go through a complete winterization every time I park it if I'm going out again in just a few weeks. Maybe purging the lines and loosening this cap would be enough?

[pitzhauler]

Don't need to run pump on city water,only when using fresh water tank

[aceinspp]

Originally Posted by cbearl78

One of the reasons I bought this model is that it's fully winterized and I plan to do some cold-weather camping with it. Hate to go through a complete winterization every time I park it if I'm going out again in just a few weeks. Maybe purging the lines and loosening this cap would be enough?

You could watch what your temps will be and maybe not have to winterize. I add a ceramic heater to inside of camper when temps get to around 30 degrees. Later RJD