Intermittent well pump starts only after tapping pressure switch - contacts issue or relay failing?

[goasfarasyoucansee]

Hi everyone,

Looking for some experienced input on an intermittent well pump issue I ran into on a service call.

Pump is about 4 years old. Customer was quoted roughly $1,200–$1,800 by others to replace the pump, with only a 1-year warranty offered, so they asked if repair was possible.

History:
- System was winterized
- After winter, water was refilled and pump would not start
- First thing I checked was the pressure switch / contact box
This is video after first attempt:

What I found:
- Visible oxidation/pitting on the contact points
- I cleaned the contacts and lightly lubricated them
- Pump started and ran normally

This is exactly what I did:

Problem:
- About 3 days later, pump failed again
- On the return visit, tapping the pressure switch box with a screwdriver caused the pump to kick on
- I cycled the pump on/off multiple times and it continued to work

So right now it’s clearly responding to mechanical vibration, which makes me think:
- Contacts are badly pitted?
- Weak spring in the pressure switch?
- Failing relay or internal contact alignment issue?

Question for the pros here:
Would you recommend replacing just the pressure switch/relay at this point, or is this usually a sign of a deeper motor or control issue waiting to fail?

I’m trying to avoid unnecessary full pump replacement if a reliable repair makes sense.

Appreciate any thoughts or similar experiences.

 

[SuperGreg]

If the problem is coming from the pressure switch and it has visible signs of deterioration, I would replace it with a new one. Sounds like it's just an issue of bad contacts.

 

[Sponsor]

 

[goasfarasyoucansee]

If the problem is coming from the pressure switch and it has visible signs of deterioration, I would replace it with a new one. Sounds like it's just an issue of bad contacts.

Contacts are great, I inspected them, and they don't have burned tips on them. Do I look in to replace entire relay from the bottom to top including pressure inlet pipe?

 

[2stupid2fixit]

Concerning the pressure switch, I think whether the contacts went bad or the magnet isnt strong enough or the spring is weak.... these are all distinctions without difference.
1. Tapping on the pressure switch causes the pump to engage and run normally. So, the pump motor is good.
2. Leaving it alone causes the pump to not start until you intervene: it's no longer automatic.
3. Arcing can generate wild amounts of heat, while dragging lots of current through the wires.

If it's a plain old Square-D or similar pressure switch, they don't cost much. Theoretically, if you earned $20 per hour, and three hours have gone by, you're already $60 into it, which is probably more than a new pressure switch costs. Change the switch. I'll bet that solves the issue.

 

[Fitter30]

Also flush the line going to the switch. Line might be full of dirt. Bottom of the switch fitting center of the hole there is a very small hole that works the bellows.