Responded to service call for 24-year-old Burnham boiler with temperature control issues in one of three zones. Diagnosed and replaced seized power head on zone valve that was stuck in open position, causing zone to overheat (85°+) regardless of thermostat setting. Noted two additional aging power heads requiring replacement, leaking gate valves at drains, leaking pressure relief valve, and 1ppm CO leak at lower left boiler jacket seal. Client enrolled in rewards program.
