Issue with AC and DC Pumps off Solar Electrical system

[Cariboocoot]

Originally Posted by rowellc

Appreciate the info. I am not a Plumber but what is a non return valve?

Charles

I believe he's referring to a check valve: it allows the water to flow in one direction only. There probably aren't any on your system, as it wouldn't be strictly necessary with the Shurflo which is a positive displacement pump (has check valves built in). Otherwise there would be one between the water source and pump (usually a foot valve in a well) to keep prime on the pump (prevents water from flowing back out of the pump and into the well). Sometimes there is one between the pump and pressure tank, particularly if it is a long run.

Which brings up another point: is it a long run from the pump to the pressure tank? If so, where is the pressure switch? It should be at the tank, not the pump. The Shurflo's (usually) built-in switch should be bypassed in such an installation.

[BB.]

A check valve.

Even if the pressure tank is too small... It sounds like there is a water leak somewhere. The pump losing prime sounds like air is getting into the system.

-Bill

[icarus]

I was going to add, check valve(s) as well as it sounds like it could be sucking air on the intake side. Tiny air leakage on the intake side will result in pumps losing the ability to pump quite easily.

The lack of a check valve may allow the pressure in the tank to bleed "backwards" up the gravity line, reducing the pressure to the net head of the gravity. (But as I think of this, the result of this would be cycling of the pump every few seconds (or minutes) regardless of usage, so I would guess that really isn't too much of an issue).

Tony

[Dave Sparks]

I am with Bill, there is a leak. Get a pressure gage $15 and tee it into the output of the pump. The 40PSI should hold for days without usage.

Other possible problems are if the pump is very close to a water heater or worse a solar water tank. You must have a checkvalve on the shurflo output to protect it's rubber valve assembly from excessive system pressure. I have seen the 40psi output peg a 100psi gage. There are only so many times you can do this.

[Texas Wellman]

1st off- you don't need a plumber, you need a water well man. Plumbers know about plumbing, water wells and pumps are not their speciality.

Sounds like your tank is too small and your on/off setting is too narrow. On/Off (rapid cycling) will kill your pump and void your warranty.

I would get a bigger tank, at least a 40 gallon equivalent bladder, or call a well guy out to look at the set-up.

Good luck.

[russ]

Can the pressure tank be 'water logged'? Leaked some of the air pressure in the bladder? That makes the active volume much smaller and would lead to rapid start/stops.

[rowellc]

Well, I have this camp and have not been able to take a shower at the camp for two summers. I just wanted to thank all of you for your advice on this particular matter. First of all, all of you who recommended getting a new plumber were absoulutely correct. I just learned a bunch of things the former plumber did wrong.
Getting the right plumber versus the wrong plumber can make all the difference in the world believe me.

The first thing the new plumber caught was the fact that I had no check valve. In case any of you don't know what that is, it stops the water that your pump has drawn from your well or submersible well from going back down into the well. I have 5 PSI water pressure gravity feed. The tank has 18 PSI minimum and 40 PSI
at the high end. The former plumber had installed a Shurflo DC pump with a 40 gallon tank. Then he had me install a jet pump with a smaller tank. In both cases
the dc pump and jetpump kept coming back on recycling if you will. Once the new plumber installed the check valve it stopped the recycling. Now the pressure is still going down and we have some sort of slow leak even when the water is turned off. The former plumber also installed the wrong size diameter lines. We needed 3/4 on the lines and we had 1/4 inch lines.

So, what did I gather from all of this. Get the right plumber, because if you get the wrong plumber you might not be able to use the shower in your Solar powered camp for two years because you were convinced that it was something you did wrong and not the plumber whom you rely on to know such things. Just FYI it was not a Solar Power issue but a plumber(not understanding Solar equipment) or plumbing for that matter. Suffice to say I enjoyed my shower for the first time...

Charles Rowell

[icarus]

Glad you fixed it!

1/4" water line? Who in the world would design and build such a system? Even in an RV water lines are routinely 1/2" minimum!

To find a leak, you can install a tee, valve or plug off all appliances that would be effected by high pressure, then pressurize the entire system with high pressure air,,,~100ps, watch the gauge drop, then listen for the hiss.

Tony

[solar_dave]

Originally Posted by icarus

Glad you fixed it!

1/4" water line? Who in the world would design and build such a system? Even in an RV water lines are routinely 1/2" minimum!

To find a leak, you can install a tee, valve or plug off all appliances that would be effected by high pressure, then pressurize the entire system with high pressure air,,,~100ps, watch the gauge drop, then listen for the hiss.

Tony

I have used the air pressure trick before, and to isolated is even further a little dish-soap and water brushed on the joints while pressurized will make it stick out like a sore thumb. It helped me find a really slow leak.

[icarus]

Originally Posted by solar_dave

I have used the air pressure trick before, and to isolated is even further a little dish-soap and water brushed on the joints while pressurized will make it stick out like a sore thumb. It helped me find a really slow leak.

That is the same trick for finding gas line leaks. Gas lines are pressurized to 30 psi for 15 minutes which is a much better test than just looking for leaks with a soap solution, as regulated gas pressure is ~1/2 psi. If it doesn't leak down with 30 psi, it sure won't leak with 1/2 psi.

Water plumbing I would pressurize to 100psi, being careful not to put that kind of pressure against certain valves like toilet fills, or dish washer or washing machine controls.

Tony