Confirm I have a bad water pump?

[David-and-Cheryl]

I think I've diagnosed a bad water pump on my Landmark, but I wanted to see if I've missed anything before I go out and buy one.

Symptom: the pump runs continuously, but there is little or no water at the faucets. It worked properly last year. This is the first time I've tried to use it since winterizing the system with compressed air, following the instructions in the HOF Winterization Guide.

What I've done:

• Verified there is water in the fresh water tank
• Verified no kinks (at least that I can see) in the supply hoses leading to the tank
• Disconnected the braided hose from the Anderson 4-way valve (the other end is connected to the suction side of the pump), put the hose in a bucket of water, and ran it for 3-4 minutes. The pump didn't prime, as far as I could tell, and obviously no water came out of the faucets.
• Disconnected the other end of the braided hose from the pump and put my finger over the connection. I did not feel any suction when I did this.

Have I missed anything?

Assuming I need to replace the pump, what is the current recommendation for the "best" replacement in terms of volume and pressure?

 

[Rollin_Free]

There should be a filter on the suction side of the pump. If it's clear you can unscrew it from the pump and examine it for a crack. When you used air to blow out the system was the pump on or off? If it was off when you purged the lines it's probably the pump because water was trapped in the plastic pump side of the motor.

I just purchased a replacement pump that ended up being a spare pump from the RV dealer about a week ago. I just made sure it was 12volts before I purchased it.

 

[danemayer]

I agree, check the bowl for cracks, especially if you didn't manually empty it when winterizing.

Flojet Variable Speed Pumps are a pretty good replacement if you need it.

 

[MTPockets]

Is the Anderson valve set to the "normal" setting. Not city.

 

[Roller4tan]

I had the same issue. Took the the pump section apart and didn't see anything obvious. Bought and installed a new pump, all better. Decided to take 'everything' apart on the pump and found the internal check valve stuck closed, thus no suction. Pushed it open from the back side. Ran pump off truck battery and felt suction on the inlet side. Now I have a spare.

 

[rhodies1]

Hello,you have nothing to lose currently so I would take the head of the pump to see if a foreign piece of debris stuck in the head holding the valve open and not letting it pick up the prime. It's pretty easy to do,take out the 4 screws and lift off,there should be a rubber sear over the valve,check the rubber to ensure there are no holes in the rubber...
the valve is spring loaded,push it back and forth to ensure it moves both ways, I have had this happen and thought I would need to replace the pump but found a small rock stuck in the valve.

 

[TedS]

Make sure the winterizing valve is closed or the pump will suck air.

 

[hoefler]

Before condemning the pump, make sure it is not air locked. I have to go through priming it every year after de-winterizing it. While the pump can push water up a considerable distance, it has difficulty pulling it up very far, especially if it has dried out. The valves need water to properly seal. Make sure the water tank is as full as possible so it doesn't have to draw it as far up to the pump. I then use the winterizing hose to draw water from a bucket to get the pump going, having the bucket higher than the pump help considerably. Once I get water flowing to all the faucets. I shut it down and switch it back to the tank. Turn the pump back on, and open a faucet. You will hear the pump change when it gets the air and then back when the water goes through it.

 

[RoadJunkie]

Before condemning the pump, make sure it is not air locked.

Yup, same process I learned the hard way. I almost bought a new pump but accidentally figured out this priming process.

 

[David-and-Cheryl]

Before condemning the pump, make sure it is not air locked. I have to go through priming it every year after de-winterizing it. While the pump can push water up a considerable distance, it has difficulty pulling it up very far, especially if it has dried out. The valves need water to properly seal. Make sure the water tank is as full as possible so it doesn't have to draw it as far up to the pump. I then use the winterizing hose to draw water from a bucket to get the pump going, having the bucket higher than the pump help considerably. Once I get water flowing to all the faucets. I shut it down and switch it back to the tank. Turn the pump back on, and open a faucet. You will hear the pump change when it gets the air and then back when the water goes through it.

So I think I basically did this as part of my original troubleshooting, even though I didn't know about the air locking problem. There's a 20" long flexible braided hose that connects the suction side of the pump to the "to pump" port of the Anderson 4-way valve. I disconnected the hose from the valve and submerged the now open end in a bucket of water sitting next to the pump. The top of the hose was higher than the pump at this point. I opened a couple of faucets inside, then I ran the pump for about three minutes. The pump never did seem to draw in any water.

How long should the pump take to self-prime like this? Maybe I didn't run it long enough?

In any case, I'd already ordered a new pump from Amazon before I saw your reply (it was during the forum outage). We'll be boondocking in a few days, so I needed to be sure that I had a working system. Once I get the new pump installed, I might do some bench testing on the old one to see if it's still usable as a spare.

- - - Updated - - -

Hello,you have nothing to lose currently so I would take the head of the pump to see if a foreign piece of debris stuck in the head holding the valve open and not letting it pick up the prime. It's pretty easy to do,take out the 4 screws and lift off,there should be a rubber sear over the valve,check the rubber to ensure there are no holes in the rubber...
the valve is spring loaded,push it back and forth to ensure it moves both ways, I have had this happen and thought I would need to replace the pump but found a small rock stuck in the valve.

Thanks. I tried this yesterday. The check valve seemed to be working fine, although I did find a couple of tiny pieces of plastic in the head assembly (not in the valve though). I don't know if those were related or not. I reassembled the pump and it still wouldn't prime.

 

[hoefler]

Try pouring water down the hose with a funnel with the pump running. Then blow in the hose to push the water to the pump. In some cases, if the pump has set dry for a a long time, it will need the additional help. When I bought our Landmark, it had set 2 years, and would not prime. It has worked since then, 7 years.