---
title: "What Is Check valve? Pool Glossary | Marina Pool Services"
description: "A check valve is a one-way valve that stops water flowing backward. Plain-English pool glossary from Marina Pool Services in Grapevine, TX."
url: https://marinapool.multisites.ai/glossary/check-valve
publisher: Marina Pool Services
phone: +1-817-896-1120
quote: https://marinapool.multisites.ai/contact
---

Equipment

# Check valve

A check valve is a one-way valve that stops water flowing backward.

A check valve lets water move one way. Pool systems use it near heaters, chlorinators, and spa setups to keep hot or chemical-rich water from flowing back into equipment.

A worn valve can leak, chatter, or stick. Signs include water draining from the pump when it is off, noise, or chemicals backing up. Replacement requires cutting into pipe, so a pro should do it. Skipping a needed check valve near an [inline chlorinator](https://marinapool.multisites.ai/glossary/inline-chlorinator) can damage equipment.

[Marina can helpPool Equipment Repair & Service](https://marinapool.multisites.ai/our-services/pool-equipment-repair)

## Related terms

-   [Inline chlorinator](https://marinapool.multisites.ai/glossary/inline-chlorinator)
-   [Pool heater](https://marinapool.multisites.ai/glossary/pool-heater)
-   [Pool pump](https://marinapool.multisites.ai/glossary/pool-pump)
-   [Priming](https://marinapool.multisites.ai/glossary/priming)

## 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)