Introduction
At Dovis Plumbing, we know your water heater works hard every day and your thermal expansion tank plays a big role in keeping it safe. This small but important device absorbs excess pressure when water heats up, protecting your pipes, valves, and water heater from damage.
Regular testing and maintenance can extend your system’s life and prevent costly repairs. Here’s how to do it safely.
What a Thermal Expansion Tank Does
In a closed plumbing system, heated water expands. Without an expansion tank, that extra pressure can cause leaks, pipe bursts, or water heater damage. Many cities now require one by code.
How Often to Test It
We recommend testing your thermal expansion tank every 6–12 months or sooner if you notice fluctuating water pressure or “banging” pipes.
Tools You’ll Need
- Tire pressure gauge
- Bicycle pump or small air compressor
- Water pressure gauge (for hose bib)
Step-by-Step Testing
- Turn off the water to your water heater.
- Locate the Schrader valve (looks like a tire valve) on top of the expansion tank.
- Use a tire gauge to measure the tank’s air pressure.
- Compare it to your home’s water pressure (should match, usually 50–60 PSI).
- If low, add air until it matches your water pressure.
- If water comes out of the valve, the bladder is damaged replacement is needed.
Maintenance Tips
- Keep water pressure between 50–60 PSI.
- Replace tanks every 5–10 years, or sooner if corroded.
- Inspect for rust, leaks, or bulging regularly.
- Schedule a plumber if you hear water hammer or notice pressure changes.
When to Call Dovis Plumbing
If your expansion tank fails, shows visible rust, or can’t hold air, it’s time for a replacement. Our licensed plumbers handle installation, testing, and code compliance so you have peace of mind knowing the job’s done right. Contact Dovis Plumbing at (954)516-1078 for a professional inspection or replacement and keep your water heater running safely for years to come.
