Boiler does not start at all, display is blank

Safety first: Use caution when working with mains voltage. Turn off power at the breaker before opening electrical compartments.

• Step 1 – Check breaker: Verify that the circuit breaker feeding the Rheem boiler is on and not tripped. Reset if necessary.
• Step 2 – Inspect external switch: Many boilers have a local disconnect or service switch. Ensure it is in the ON position.
• Step 3 – Test power at boiler: With a multimeter and appropriate safety precautions, confirm that correct voltage is present at the boiler’s power terminals.
• Step 4 – Internal fuses: With power off, inspect any internal fuses on the main PCB. Replace blown fuses only with identical ratings and investigate the cause.
• Step 5 – PCB replacement: If power is present at the board but the display remains dead, the main control PCB or display board may have failed and require replacement.

Warning: If fuses blow repeatedly, do not continue replacing them. There is likely a short circuit that must be diagnosed by a professional.