Water pump will not prime

[mckmike]

I have a 2011 Shamrock 23SS. The water pump will not prime from the water tank. It will prime from a bucket a foot or so from the pump. Also, I can suck on the intake like and draw the water out of the tank (cheeks are a bit sore); however, as soon as I release the suction off the water drains back to the tank. Based on this I am assuming there are no leaks or kinks in the intake line.

It would seem the pump is not creating enough sucking pressure. If I put my thumb on on the end of a short hose connected to the pump, how much suction should there be?

Any help would be appreciated.

[bikendan]

have you opened up the faucets when doing this?

[buzzmonster]

Two rings to check as I had a similar issue

1) That the vent line from the tank is clear so that as water is pulled from the tank air can go into replace it otherwise the pump is trying to pull a vacuum.

2) Open a tap (facet) down stream of the pump again to let air out the system otherwise the pump is simply compressing the air which is compressible whereas water is not. You need to get the air out of the system or the will simply cavitate.

[fonzie]

Could it be that you have a winterizing valve that has not been turn back to normal suction? I have one on my 8319SS.

[TURBS]

Open pressure relief valve on hw heater its going to fill first any way.

[mckmike]

Thank you for the suggestions.

I have opened up the faucets to let air escape. After several minutes it is still mostly air. I then used hose hook up to purge air out of the lines. When I turn off the hose and go back to the pump, the water flow is very low and after a few mintues it goes back to mostly air.

There is no separate winterizing valve. The inlet goes to through a strainer and then to the pump. I have also tried eliminating the strainer and there is no change.

At this point I am bypassing the water heater to minimize the variables.

I have had the problem for the past couple of years. I took it in for service at the end of last season and the dealer said they adjusted the pump. I did not use it after that. I only used the pump to draw in anti-freeze to winterize the unit. Drawing in from the gallon bottles (no head) it worked fine. Build pressure and stopped as it is supposed.

Now I am attempting to dewinterize and draw bleach water through the system to sanitize. Unfortunately, it does not seem to draw from the supply tank.

[TURBS]

How much water is in the tank?

[buzzmonster]

Originally Posted by mckmike

Thank you for the suggestions.

I have opened up the faucets to let air escape. After several minutes it is still mostly air. I then used hose hook up to purge air out of the lines. When I turn off the hose and go back to the pump, the water flow is very low and after a few mintues it goes back to mostly air.

There is no separate winterizing valve. The inlet goes to through a strainer and then to the pump. I have also tried eliminating the strainer and there is no change.

At this point I am bypassing the water heater to minimize the variables.

I have had the problem for the past couple of years. I took it in for service at the end of last season and the dealer said they adjusted the pump. I did not use it after that. I only used the pump to draw in anti-freeze to winterize the unit. Drawing in from the gallon bottles (no head) it worked fine. Build pressure and stopped as it is supposed.

Now I am attempting to dewinterize and draw bleach water through the system to sanitize. Unfortunately, it does not seem to draw from the supply tank.

Hmmmm so it works from the city water connection but not the pump ?

If that is the case and you can hear the pump running , check that the inlet filter on he pump is not blocked. Other than that I would take the pump out and test it on the bench with a bucket of water hooked to the inlet side. This is assuming that it does work from the city water connection, then if the inlet piping is clear to the pump sounds like a pump problem.

Before opening it up I would bench test as I said but if that fails open it up it is a simple diaphragm pump, it could be a sticky check valve or a ruptured diaphragm .......

[mckmike]

Buzzmonster,

You may have hit on the solution.

It appears it may be an obstructed vent. There is no easy way to disconnect this to see if it is clear. I filled the tank as full as possible holding the hose in the fill tube to try and get the water to come out of the vent. It would barely come out. I used a needle to poke through the holes on the metal screen to open it up.

I turned the pump back on and opened a faucet and it quickly primed. When I opened and closed the faucet the pump would turn on and off as expected. I then proceeded to open all the other valves one at a time and the air quickly escaped and I had good water flow.

So far so good. I will just have to see if everything continues to function when the tank gets lower.

Thank you for the recommendation. I also thank everyone else for their suggestions.

[J672]

Originally Posted by mckmike

I have a 2011 Shamrock 23SS. The water pump will not prime from the water tank. It will prime from a bucket a foot or so from the pump. Also, I can suck on the intake like and draw the water out of the tank (cheeks are a bit sore); however, as soon as I release the suction off the water drains back to the tank. Based on this I am assuming there are no leaks or kinks in the intake line.

It would seem the pump is not creating enough sucking pressure. If I put my thumb on on the end of a short hose connected to the pump, how much suction should there be?

Any help would be appreciated.

Check to see if you have a plastic strainer that is in line next to the pump had similar problem turns out it had held a little water over the winter and froze and got a little crack and it would not prim. Turned out the pump was sucking just enough air that the water could not make it up the line . Hope this helps or at least gives you a new direction .
Good luck