If we had a dollar for every customer who’s asked us “what does 60/40 mean?” on the phone, we’d have a lot of dollars. The pressure switch is one of the smallest, cheapest parts on your well system — and one of the most common reasons people lose water. Here’s what it actually does, what those numbers mean, and how to know when it’s time to replace it.

What a Pressure Switch Actually Does

The pressure switch is the brain of your well pump — it tells the pump when to turn on and when to turn off. When water pressure in your house drops below a set point, the switch closes and the pump kicks on. When pressure climbs back up to the upper set point, the switch opens and the pump stops. Without it, your pump would either run constantly or never start at all.

40/60 vs 30/50: What the Numbers Mean

The two numbers are the cut-in pressure (when the pump turns on) and the cut-out pressure (when it turns off). A 40/60 switch turns the pump on at 40 psi and off at 60 psi. A 30/50 switch turns it on at 30 psi and off at 50 psi. Most modern Connecticut homes run on a 40/60 switch because the higher pressure feels better at the showerhead. Older systems and homes with old galvanized plumbing often stay on 30/50 to avoid stressing fragile pipes.

Signs Your Pressure Switch Is Failing

The most common signs we see on service calls are: water suddenly stopping at every fixture, the pump running constantly without ever shutting off, the pump short-cycling on and off rapidly, or weak pressure throughout the house even though the pump “sounds fine.” Sometimes you’ll hear the switch clicking repeatedly, or you’ll see scorch marks on the contacts when the cover comes off.

Why Switches Fail

Three things kill pressure switches: worn contacts from years of cycling, a clogged or stuck pressure-sensing diaphragm (often from sediment), and corrosion. A switch that’s been on the system for ten years and is now misbehaving has almost certainly hit the end of its life. They’re consumable parts.

Can I Replace It Myself?

Technically yes, but we don’t recommend it. The switch is wired to 240V on most submersible setups, and getting the cut-in and cut-out settings adjusted correctly takes a gauge and some practice. The switch itself is a $40 part — the labor and the diagnostic that goes with it are what you’re paying for.

What It Costs to Replace

For most Connecticut homes, replacing a pressure switch is a quick job that fits inside our flat-rate $169-plus-tax diagnostic visit, with the part billed separately. We’ll also test the rest of the system — tank, pump amperage, lines — so you don’t end up replacing one part when something else is the actual cause. See our full well pump service options.

When to Call

If you’ve lost water, the pump is short-cycling, or pressure feels off, don’t keep cycling the breaker on and off — that can damage the pump. Contact Mad River Well Services and we’ll diagnose the real cause before any part gets replaced.

Frequently Asked Questions

How long does a pressure switch last?

Five to ten years is typical, depending on water quality and how often the pump cycles. Hard water and sediment shorten the lifespan.

Can I switch from 30/50 to 40/60?

Sometimes yes, but only if your pressure tank, plumbing, and pump are rated for the higher pressure. We check before recommending it.

Why does my pump short-cycle?

Short-cycling is usually a waterlogged pressure tank, not the switch — but a switch with bad contacts can cause it too. We test both before recommending a part.

Will replacing the switch fix my low pressure?

It depends on the diagnosis. Sometimes yes. Sometimes the switch is fine and the real problem is a leak, the tank, or the pump. That’s why we test before we replace.