---
title: "What Is Pressure switch? Pool Glossary | Marina Pool Services"
description: "A pressure switch is a safety part that tells the heater water is flowing. Plain-English pool glossary from Marina Pool Services in Grapevine, TX."
url: https://marinapool.multisites.ai/glossary/pressure-switch
publisher: Marina Pool Services
phone: +1-817-896-1120
quote: https://marinapool.multisites.ai/contact
---

Equipment

# Pressure switch

A pressure switch is a safety part that tells the heater water is flowing.

The pressure switch protects the heater. If water flow is too low, it blocks the burner so the heater does not overheat. A failed or dirty switch can shut the heater off even when flow is fine.

Check first for a dirty filter or a closed valve, since those cut flow too. If the heater still will not fire, the switch may be at fault. Replacing it is a job for a qualified pro, because it ties into gas and safety systems. Do not bypass it. A bypass can cause a dangerous overheat.

[Marina can helpPool Heater Repair & Installation](https://marinapool.multisites.ai/our-services/pool-heater-repair)

## Related terms

-   [Pool heater](https://marinapool.multisites.ai/glossary/pool-heater)
-   [Gas heater](https://marinapool.multisites.ai/glossary/gas-heater)
-   [Igniter](https://marinapool.multisites.ai/glossary/igniter)
-   [Flow switch](https://marinapool.multisites.ai/glossary/flow-switch)

## Need a hand with your pool?

Call or text and tell us what your pool needs. Estimates are free for qualifying services, and same-day estimates are possible when the schedule allows.

[Call (817) 896-1120](tel:+1-817-896-1120)[Get a quote](https://marinapool.multisites.ai/contact)

![A pool technician working on an equipment pad](https://marinapool.multisites.ai/_astro/technician-equipment-pad.BW5xZMNY_Zum1K5.webp)