Amana Menumaster Err3

What does Amana Menumaster Err3 mean?

Err3 is a service code shown on the display of an Amana Menumaster commercial microwave when the control detects a failed high-voltage (H.V.) board. As with the other H.V. board codes, the control stops the cook cycle and posts Err3 to indicate that the board responsible for driving the magnetron circuit has failed and must be replaced before the oven heats normally again.

Symptoms

• Display shows Err3 during operation.
• Oven does not heat or will not start.
• Magnetron fails to energize on a cook cycle.
• Code may return after a power cycle if the board is faulty.

Common causes

• Failed high-voltage (H.V.) board.
• Damaged drive or relay components on the H.V. board.
• Fault induced by an electrical event in the high-voltage circuit.

Diagnostic steps

1. 01

   Power down and retest first

   Unplug the oven for one minute, reconnect power, and retest. If the unit operates properly, no service call is needed.

2. 02

   Observe high-voltage safety procedures

   Check grounding and discharge the high-voltage capacitor before any repair; 208/230 VAC is present in the H.V. board, power relay, and low-voltage transformer primary.

3. 03

   Confirm the fault persists

   Re-run a cook cycle after the reset to verify Err3 returns rather than being a one-time event.

4. 04

   Replace the high-voltage board

   The manual's corrective action for Err3 is to replace the H.V. board with the correct part, then verify normal heating.

When to call a professional

Replacing the high-voltage board involves a circuit carrying 208/230 VAC and a high-voltage capacitor that must be discharged before contact. The manual restricts these repairs to a trained service technician following the eight caution steps. If you are not qualified to service commercial microwave high-voltage circuits, stop after the power-cycle retest and contact an authorized Amana Menumaster service agent.