Arrived onsite to investigate a boiler leaking from the relief valve. During a thorough evaluation, I found that the expansion tank had failed, which was causing the relief valve to discharge. The tank was replaced in 2022 and is still under its 5-year manufacturer warranty. I presented an estimate for the labor to replace the expansion tank, and the customer approved the work. Replaced the tank and verified proper operation. The system is working correctly at this time.