Weil-McLain indirect water heater provides hot water initially, then quickly runs cold during use.

Safety first: Water temperature can fluctuate; test carefully at fixtures.

• Check usage vs. capacity: Compare your hot water usage (showers, appliances) to the tank’s storage and recovery ratings. Excessive simultaneous use can exceed capacity.
• Inspect mixing valve: A malfunctioning mixing valve can allow too much cold water to blend, reducing effective hot water volume. Adjust or replace if necessary.
• Check boiler priority: Ensure the boiler control is set to give DHW priority so the tank can recover quickly during draws.
• Dip tube inspection: If accessible, have a technician inspect the cold inlet dip tube inside the tank; a broken tube can cause cold water to mix at the top and shorten hot draws.