11/01/2026
Apprentice Questions #1: What does a pressure-reducing valve have to do with a water heater?
Water pressure around Bryan and College Station can run high. A PRV helps keep a home’s water pressure at 80 psi or less. When a PRV, check valve, or backflow preventer creates a closed system, water expands as it heats. A properly sized thermal expansion tank gives that water room to expand.
The expansion tank manages thermal expansion; it does not lower excessive incoming water pressure. That’s why checking both matters during a water heater replacement.
SDS Plumbing serves Bryan, College Station, and the Brazos Valley.
Full breakdown and Q&A on our subreddit: https://www.reddit.com/r/SDSPlumbing/comments/1xk2s3s/how_a_prv_water_heater_and_expansion_tank_work/