Warm water doesn't have a strong direct mechanism against reflux the way baking soda or an antacid does, but it's a genuinely low-risk habit that some people find helpful, and there are a few plausible reasons why.
Possible reasons it helps some people
Warm liquids may help move food through the stomach a little more comfortably than very cold drinks, and sipping warm water slowly (rather than gulping a large glass) naturally encourages a slower pace, which is itself a reflux-friendly habit. Some people also find that warm water helps clear a lingering sour taste or mild throat irritation after a reflux episode, more through dilution and rinsing than any chemical effect.
What it isn't
Warm water isn't a substitute for antacids during an active, uncomfortable episode, and it doesn't neutralize acid the way baking soda does. It's better thought of as a mild, supportive habit — something to sip between meals or first thing in the morning — rather than a treatment for symptoms already underway.
A simple way to try it
Sipping a small glass of warm (not hot) water between meals, rather than large amounts with food, is a reasonable, low-risk habit to test for a couple of weeks and see whether it makes a noticeable difference for you specifically.
