Boiler will not start at all, no lights or display, appears completely dead

Safety first: Do not work on live electrical circuits. Turn off power at the breaker before opening any covers.

• Check breaker and switch: Verify the boiler's dedicated breaker is ON and has not tripped. Confirm the boiler service switch near the unit is in the ON position.
• Inspect power light: Some Burnham boilers have a power indicator LED. If it is off, there is likely no power reaching the control.
• Examine junction box: With power off, remove the cover on the electrical junction box at the boiler. Check for loose wire nuts or burned connections. Tighten as needed.
• Check internal fuse: Many controls have a small replaceable fuse. If blown, replace only with the same type and rating. If it blows again, stop and call a technician.
• Restore power and test: Turn the breaker back on and see if the display or lights come on. If still dead, the transformer or control board may be failed.