Professional diagnosis and replacement of expansion tanks and TPR valves. Prevent leaks, banging, and costly damage.
The expansion tank on a water heater is one of the smallest components in a residential plumbing system, and one of the most commonly ignored. When it fails, the consequences range from minor leaks to ruptured tanks and full-room flooding.
Koda Plumbing Service Co treats expansion tank and pressure relief valve work as scheduled maintenance. A planned replacement is a one-hour appointment. An unplanned failure is often an expensive emergency.
Every service in St. John follows the same proven process.
Pressure reading at inlet
Expansion tank pre-charge check
TPR valve test
Visual inspection of discharge & pan
Written findings & recommendations
We test pre-charge and replace proactively before external leaks appear. Proper sizing and pre-charge settings guaranteed.
We diagnose the root cause before replacing. Dripping TPR valves often indicate upstream pressure issues.
We identify the source of banging or knocking sounds and resolve pressure spikes safely.
Flat-rate full system check with written report. Ideal for peace of mind or pre-purchase inspections.
"They had a tech out by 11 a.m., diagnosed a failed expansion tank, replaced it, and tested everything. Bill was exactly what they quoted."
— Patricia W.
"Saved me from buying a $1,400 water heater I didn't need. The banging was just a failed expansion tank."
— Gregory L.
"They flagged a TPR valve issue and explained the real cause. Honest service during a home inspection."
— Stephanie A.
We quote real numbers on the call. Final invoice always matches the quote.
Five to ten years for most residential models in St. John, depending on water pressure and quality.
High system pressure, failed expansion tank, or worn valve seat. We diagnose before replacing.
Yes, but correct tank size, pre-charge, and mounting are critical. Incorrect pre-charge is the most common mistake.
Yes if you have a closed system (pressure regulator or backflow preventer). Most modern St. John homes do.
45-minute professional inspection with real pressure readings and honest recommendations.
Click Here to Call (888) 466-2103