FL Plumbing Code Requirement
Florida plumbing code requires a thermal expansion tank on ALL closed water supply systems — which includes virtually every FL home on city water with a backflow preventer or pressure reducing valve installed. Missing expansion tank = code violation + voided water heater warranty.
Why FL Homes Need a PRV
FL municipal water pressure often exceeds 80 PSI (the max safe residential level). High pressure stresses pipes, valves, and water heater tanks — shortening lifespan and causing drips. A pressure reducing valve (PRV) set to 60-70 PSI is the fix.
Bundle & Save
If your plumber is already there, bundling an expansion tank + PRV saves 20-30% vs. two visits. Both installed typically run $450-900.
Why FL Homes Need Expansion Tanks
Florida's plumbing code (adopted from IPC) requires expansion tanks on closed-loop systems. When your water heater heats water, the volume expands; on a closed system (backflow preventer installed), that pressure has nowhere to go. Without an expansion tank: pressure relief valves drip constantly, water heater tanks fail prematurely, and supply lines and fixture valves are under chronic stress. FL homes built after ~2006 should have expansion tanks, but many older homes were retrofitted with backflow preventers (required for reclaimed water connections) without the required expansion tank.
Why FL Homes Need Pressure Reducing Valves
FL municipal systems often run at 90-120 PSI; safe residential maximum is 80 PSI. Symptoms of high pressure: faucets drip after replacing cartridges, toilet fill valves fail repeatedly, water hammer, water heater T&P valve dripping, water heater tank life cut in half.
FL Reclaimed Water Note
FL has one of the highest rates of reclaimed water irrigation in the US. Any FL home connected to reclaimed water for irrigation MUST have a backflow preventer — and therefore MUST have a thermal expansion tank on the water heater.
How to Find Your Expansion Tank / PRV
Expansion tank: look near your water heater for a football/egg-shaped tank (2-5 gallon) on the cold water supply line — roughly basketball/football sized. If you don't see one and you're on city water, you likely need one.
PRV: look for a bell-shaped brass valve on your main supply line, usually within 12 inches of where water enters the home (near meter, crawl space entry, or utility room), often with a pressure gauge. If the gauge reads above 80 PSI or there's no gauge, have it tested and adjusted.
EMERGENCY: T&P Valve Dripping
The T&P (temperature & pressure) relief valve is the last line of defense against a water heater explosion. If it's dripping, either pressure is chronically too high (add PRV + expansion tank) or the valve itself is failing (replace). Do NOT cap or plug a dripping T&P valve.