A customer complains of constant dripping from the temperature and pressure relief (TPR) valve on their domestic hot water tank. You inspect the system and find a non-code-compliant check valve installed on the cold water supply line without an expansion tank. What is the most appropriate immediate action to take?

Question: A customer complains of constant dripping from the temperature and pressure relief (TPR) valve on their domestic hot water tank. You inspect the system and find a non-code-compliant check valve installed on the cold water supply line without an expansion tank. What is the most appropriate immediate action to take?

Answer options:

• Replace the TPR valve immediately.
• Drain the hot water tank and remove the check valve. ✅ Install an appropriately sized thermal expansion tank.
• Reduce the thermostat setting on the hot water tank.

Correct answer: Install an appropriately sized thermal expansion tank.

Explanation: The constant dripping of the TPR valve, coupled with a check valve on the cold water supply and no expansion tank, indicates thermal expansion is occurring within a closed system. Installing an appropriately sized thermal expansion tank will absorb the expanding water and prevent the pressure buildup that causes the TPR valve to open. Replacing the TPR valve or adjusting the thermostat would not address the root cause of thermal expansion.