Shurflo Pressure Switch

[JusDreaming]

Our water pump has decided not to cut off anymore!!! So my question is there a way of testing the switch, before buying a new on for $50. I have checked for leaks and nothing found. It is a 4212 series pump.

[GordMay]

Originally Posted by JusDreaming

... I have checked for leaks and nothing found...

The sealed pressure switch on the Shurflo 4901-4212 "Aqua King" 4.0 GPM Domestic Water Pump has an adjustable 45 PSI Shut Off Pressure. Check (again) to ensure that you don’t have a minor pinhole leak (or ‘leaky’ faucet) that prevents building up this pressure in the system.

See ➥ http://www.shurflo.com/files/Educati...-4202%2012.pdf

Good luck.

[Play Actor]

And, if you have to replace it, I have had excellent service from Square D pressure switches designed for well systems. They're about $15 from any good hardware store, and you can adjust the on and off pressure to suit. They are a little bulky, but they last forever. Just use a hose barb on the switch and a T hose barb in the pressure line, and forget high priced built in pressure switches.

[colemj]

Yes, you can test the switch - it is just a simple contact switch. Take it off, put an ohm meter across the leads and press in the switch diaphragm. You should have continuity before pressing the diaphragm, and no continuity after. Anything different than this is a bad switch.

Mark

[sailvayu]

If the switch checks out good keep in mind a water logged expansion tank or wrong pressure in the expansion tank will cause the pump to not shut off. (Assuming you have an expansion tank) Also air in the lines or water heater can cause this problem as well. It can help to have a pressure meter in the system to be able to know what is going on. Good luck

[JusDreaming]

found a small leak at the bottom of the pump housing/ drive assmembly, and naturally no one has the replacement locally. I tried tightening and still leaks even though visible damage to gasket

[Jim Cate]

Originally Posted by Play Actor

And, if you have to replace it, I have had excellent service from Square D pressure switches designed for well systems. They're about $15 from any good hardware store, and you can adjust the on and off pressure to suit. They are a little bulky, but they last forever. Just use a hose barb on the switch and a T hose barb in the pressure line, and forget high priced built in pressure switches.

Great idea, PA!

I think this sounds like a good spare to carry on board for anyone who cruises to places beyond the long arm of Worst Marine.

Thanks

Jim

[skipgundlach]

I'll start a new thread on this but...

My pump cycles for no apparent reason. The original switch was bad based on the backflow I got when pressurized. The new switch changed the frequency and duration of the runs, but it still cycles for no apparent reason:

We have a large accumulator, and a substantial amount of water has to pass before it drops pressure enough to kick the pressure switch. So, if there were a leak, it would be substantial in the amount of water it would display on looking...

But we find no such leak (or any at all, for that matter.

So, I call Shurflo. The rep tells me that one of the reasons they discontinued this pump 4-5 years ago is that the firmware started to fail.

Firmware??? I just replaced the switch. No, it's in the BASE (the part you screw to the bulkhead or shelf) - despite there being no electrical connection between the base and the pump body, on which side it mounts, sez he.

And the firmware 'remembers' what it's been doing, and continues to do that; in my case, due to the leakdown, is that it cycles often.

The solution, rep sez, if there is any hope, is to physically disconnect the wires from power; a breaker isn't sufficient - it still has a micro-amp draw if there is a physical connection (WTF??). Otherwise, even if we were to send the pump to them, there's nothing he could do about it (base obsolete? I didn't answer the question, as he was addressing the firmware issue). The parts PDF shows, but does not identify as a part number, the base. Seems to me that this would be a replacement item if there's something which controls the pump.

Has anyone else heard of "firmware" in a Shurflo pump? Or had our issue and solved it?

Thanks.

L8R

Skip

[zeehag]

i solved the persistent--yes it even happens with my other surflow pumps --by flipping the system off between use. is easy. just flip a breaker switch and ta daa no more cycling of pump. i checked for leaks--only ones i have are in tank at the 40 yr old welds. i am so not worried on this. i tried 3 different pumps, all 3 cycle.

[skipgundlach]

Originally Posted by zeehag

i solved the persistent--yes it even happens with my other surflow pumps --by flipping the system off between use. is easy. just flip a breaker switch and ta daa no more cycling of pump. i checked for leaks--only ones i have are in tank at the 40 yr old welds. i am so not worried on this. i tried 3 different pumps, all 3 cycle.

Well, just for amps, before we got our new switch, we shut it off other than when we wanted to use water. And of course, it didn't run.

But the new switch is behaving in the same way, despite my having physically disconnected both power and ground (I still don't buy that a thrown breaker provides any energy). I've also mucked with the pressure setting (off the shelf it was pretty low) to no avail.

As I can't find a leak, I can't assign a reason for the pump to cycle.

As there is NO reference I can find to firmware, other than this rep's comments, I'm suspicious of that fault.

But, what else could be happening??

[skipgundlach]

Firmware, and ANY voltage/current present certainly rang as intensely odd. So, to not possibly get the same guy in Indiana...

Called the CA office, got Mel, who offered to have me call him back directly to let him know what happened.

His (and others here and there) opinion was that there was a bit of debris in the valves; in the valve segment seen in http://legacy.shurflo.com/pdf/Marine...-4901-4202.pdf there are inlet and outlet valves which I can rotate by hand; do it, he sez. Also wash with soapy water. Both designed to remove any small particles.

When I took off the pressure switch, I found a tiny speck of something under it; maybe a grain of sand, or maybe a tiny paint speck which somehow managed to get sucked up after flowing into our tank during rainwater catching, or something. So, perhaps...

But my next step is to take off the pump, again, take it apart, get the valve segment (#3 in the blowup) and wash it after, looking at it under high magnification before and after. With any luck something will be obvious.

But I am beyond irritated that I was told there was a check valve which failed, and could not be serviced, in the pressure switch by one rep, and Mel has never heard of ANY firmware in Shurflo, and denies there being a check valve, other than the valves which pump the water in.

Bleah.
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[zeehag]

ok so no wires to the pump and it cycles?? and no wires touching anything at all.... not wired up and main power switch spozedly off??? hhmmmm yup haunted. only explaination.
warrantee vs rebuild vs exorcist. your choice. without pix we cannot see...

[skipgundlach]

Originally Posted by zeehag

ok so no wires to the pump and it cycles?? and no wires touching anything at all.... not wired up and main power switch spozedly off??? hhmmmm yup haunted. only explaination.
warrantee vs rebuild vs exorcist. your choice. without pix we cannot see...

No, that's not what I said...

It cycles and stops via the breaker. The first guy was smoking something, I think, both in the firmware assertion and the 'unplug it - the breaker's not enough to stop the firmware' weirdness.

But, it still does cycle - and (not related) there's an air leak SOMEWHERE in the intake side - and, maybe (didn't wait around very long to verify that; it could have just been drips after I turned it off and took off the fitting) still has backwashing leak, despite my taking the valve assembly off, thoroughly cleaning it and rotating each valve to better dislodge any debris possible.

Upon reassembly,there's essentially no change other than that the pump section now has a small leak, dammit.

I'm away from the boat at the moment so can't take it down, yet again, and take it all apart, yet again, in order to see if there is any evidence suggestive of a leak point in the base of the valve (on the pump mechanism, which acts as a gasket for the valve body), and put it all back together again.

Bleah.

[a64pilot]

Zee, if you have tried three pumps and all three cycle, you have a leak girl


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[jamhass]

IF it is one of the variable speed pumps, there is indeed an electronic circuit inside the motor (located on the brush holder) that can (and does) burn out. You can hot wire the circuit, but then the circuit breaker becomes the only switch, or you can use an external one as previously mentioned.