Shurflo water pump intermittent failure

[Calypso52]

We have a five year old Shurflo fresh water pump. No issues in that time. Now is working intermittently. Sometimes runs for a minute, sometimes for a few seconds. Full force when it is on so I don't suspect the motor. Appears to have power to pump. Took switch off pump and put back on. Immediately powered up and then stopped again.
They sell just the switch or the switch and upper head. Anyone have a pump that failed and brought back to life with either of these parts?
An entirely new pump here in the Caribbean is $400. Yikes.
Thanks.

[daletournier]

I just happen to be replacing the switch on mine today. I couldn't just purchase the little switch I had to purchase the whole housing of a later model then transplant the switch, $80.

The easy way to test if it's the switch or not is to bypass the switch and see if the pump operates correctly by just switching it on and off at the breaker with a tap open.

Its most likely the switch.

[Cheechako]

It can be the switch. But it can be air in the system pipe or a bad accumulator also. Air cushions and doesn't give a "hard stop shock" to the switch and it wont activate sometimes.

[Calypso52]

Thanks Dale, that is exactly it. Now we can at least draw water and take showers if someone is at the switch. If Budget Marine here in Bonaire doesn't have the switch (highly unlikely) I'll get an inexpensive pump to tide us over and bring a pump head/switch back when we return.

[stormalong]

I am not familiar with the Shurflo but I have discovered a flaw in all water pump switches and a long term solution.

The problem:

The pressure switches cannot handle the current that the motor draws. All of these switches are destined to fail after a few years.

The solution:

Use the pressure switch to power a high current relay which powers the motor. I use the automotive 20 amp headlight relays that you can get anywhere. I also use a relay socket so that they are easy to replace.

I have done this on my water pressure, bilge pump and deck wash pumps. The relays last a very long time because they are higher rated than the micro switches in the pressure switches or the bilge pump float switches. They are easily changed and you can get them in any auto parts store. All Electronics sells them cheap as well as the relay sockets. Even at auto parts store prices the cost to repair is much less that the cost of a custom switch from any pump manufacturer.

[Stu Jackson]

Have you read the troubleshooting guide in the manual?

[Olorin]

As many people have stated, its likely the switch. I got the part number from a failed one of ours and bought about 20 of them for not many dollars.
I'm replacing mine today.
Good idea Stormalong. I have relays in place for my starter motors and have bought a box of 12 of them with sockets from Amazon.

[jamhass]

You can also use an inexpensive independent pressure switch, such as used on a water well. Likely readily available anywhere. A little re-plumbing and you are good to go.