No hot water at faucets; Weil-McLain indirect water heater tank is cold even though boiler is operating normally.

Safety first: Turn off power to the boiler before working on circulators or wiring. Hot water can cause burns; use caution.

• Check tank temperature setting: Verify the tank aquastat or boiler DHW setpoint is set high enough (typically 120–140°F). Adjust if necessary.
• Verify circulator operation: During a hot water call, the indirect tank circulator should run. Listen for motor noise and feel the piping to and from the tank coil; it should get hot.
• Inspect valves: Ensure all valves in the indirect loop are open. A closed valve will prevent flow and heating.
• Bleed air from loop: Use purge valves on the indirect circuit to remove trapped air until a steady stream of water flows.
• Replace faulty components: If the circulator does not run with power applied, or the tank sensor/aquastat does not call for heat when the tank is cold, those parts may need replacement.