Fresh Water Pump Problem

[JoLin]

Does the water pump ever fail this way? I'm getting frustrated...

With all faucets and transom shower off, the fresh water pump kicks on for about 3 seconds every 2 minutes. I've traced the water lines and every fitting from the pump to the galley faucet, to the head faucet, to the transom shower and to the water heater. Not a trace of water anywhere.

Soooo, does the pump's pressure sensor ever fail? Can it kick on even if the lines are holding pressure? I don't know the internals of them, but I'm out of ideas.

 

[louiefl]

Re: Fresh Water Pump Problem

Basic hydraulic principle is that if there is no pressure drop, there can be no flow. If your pressure goes down causing the pump to kick on, then you must have flow (ie, leak) somewhere. You can get a pressure gauge that hooks up to a hose bib at home depot and I'm sure an adapter to connect it to the faucet or maybe a fresh water washdown bib if you have one.

If you get a pressure drop before the pump kicks on (and it climbs until it shuts off), I would try isolating components until it quit doing this. Also, if you can adjust the pressure switch to turn off at a lower setting, try that and see if it solves the problem. Report back and let us know.

 

[cobalt1999]

Re: Fresh Water Pump Problem

Check valve in the pump can be leaking back to the tank.

 

[JoLin]

Re: Fresh Water Pump Problem

Okay, thanks. I understand the principle. However, I saw the slight possibility that a faulty pressure sensor might cause the pump to cycle, whether or not there was a pressure drop in the system; or that a faulty pump might allow water to leak back to the tank, decreasing system pressure and causing the pump to cycle. I figured that either was a longshot, but somebody might have seen it.

What you suggested is what I had in mind for 'someday' if nobody else has had a different experience. Given how tightly packed the plumbing is, It's gonna be a tedious process.

 

[JoLin]

Re: Fresh Water Pump Problem

Check valve in the pump can be leaking back to the tank.

We were posting at the same time. Thanks, I'll look into that.

 

[JoLin]

Re: Fresh Water Pump Problem

SUCCESS!

After checking again that all the fittings (tank, pump, galley faucet, head faucet, transom shower and water heater) were still dry, I got the model of the pump and went to the Shurflo site. Found that the pump consists 5 sub-assemblies, one of which is a replacable valve assembly. Called Shurflo, where a nice woman confirmed that, with age, the diaphragms in the valve assembly can start to leak back.

I figured it was worth a shot, so I ordered one thru WM (which unbelievably had the best price on it). Took the pump apart, installed the new assembly and, voila! Problem seems to be solved. I left the pump on all day Sunday and never heard it kick on unless we were running the water.