ACP Amana High-Speed Oven Error Code H3: Main Board
H3 on an Amana Xpress AXP22 or MXP22 touch panel oven is another main board code, and the maker table lists replacing the board, as it does for A0 and H2. The oven stops because the control cannot trust the board. Pull the plug, wait a moment, replug, and call us if H3 shows again.
Medium: the oven stops because the board cannot be trusted, but leaving it off is safe.
- Code
- H3
- Maker
- ACP Amana
- Equipment
- High-speed ovens
- Applies to
- AXP22 / MXP22 (touch panel)
What does ACP Amana error code H3 mean?
H3 joins A0 and H2 as a main board entry. The main board runs the magnetrons, the heater and the fans, and the control stops the oven because it can no longer trust the board that does all that. The maker table lists replacing the main board for H3, as it does for A0 and H2. H3 shows on the display. The manual's list names a main board that the maker tables list for replacement, a harness plug loose or burned at the main board, unstable outlet power that has stressed the board, and heat or damp damage inside the board area. The owner step is to pull the plug, then push it in again after a short pause. If H3 shows again, keep the oven switched off and call us. Tell us whether the lights flickered or a breaker tripped beforehand, because surges damage boards. The board is inside the sealed body next to high voltage parts, so nobody should open it, and a technician checks the supply and harness before condemning the board.
Affected models and control systems
This applies to the Amana Xpress AXP22 and MXP22 touch panel combination ovens, as covered in the ACP Commercial Service and Training Manual. The older AXP20/MXP20 list H-2 and H-3 together.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- H3 on the display
- The oven stops and will not continue
- The oven will not start a new program
- The code returns after replugging
Possible causes
Listed in ACP Amana's documentation
- Main board failed and due for replacement
- Harness plug loose or burned at the main board
- Unstable outlet power stressing the board
- Heat or damp damage in the board area
Other likely causes — what usually sits behind error code H3 on this control. A technician confirms which one it is before any part is replaced.
- A breaker or wiring on the oven's circuit that trips or sags, dropping the board's supply during heating
- A harness plug at the board with a loose terminal that arcs lightly under load
Safe checks before calling for service
- Pull the plug, then push it in again after a short pause.
- If H3 shows again, keep the oven switched off and call us.
- Tell us whether the lights flickered or a breaker tripped beforehand.
- Do not open the sealed body.
- Note how long the oven ran before H3.
How a technician diagnoses error code H3
- Read the code and confirm it repeats.
- Check outlet voltage idle and under load.
- Inspect the harness plugs for burned terminals.
- Check the board for damp and heat damage.
- Replace the main board after the supply and harness are sound.
- The board is inside the sealed body next to high voltage.
- Supply problems must be found or they return after a new board is fitted.
- The maker table lists board replacement, which is technician work.
How error code H3 differs from similar codes
A0 and H2 are also main board entries on this oven. H3 is listed on its own, and the maker table gives the same replacement action.
Technical reference
- Document
- ACP Commercial Service and Training Manual
- Edition
- December 2011, 16400012
- Models / control
- AXP22 / MXP22 (touch panel)
- Section
- Display Diagnostics - Error Codes: AXP20/MXP20 (hyphenated codes, M-0 to M-2) printed p. 58 (PDF p. 65); AXP22/MXP22 printed p. 74 (PDF p. 81)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related ACP Amana high-speed oven error codes
Do A0, H2 and H3 all mean a bad board?
They all point to the main board, and the maker table lists replacement for each. We test supply and harness first.
Can a power surge cause H3?
Yes. Surges damage boards, so tell us about flickering lights or tripped breakers.
Is a restart enough?
A restart is fine once. If H3 returns, the oven should stay off.
Need help with ACP Amana error code H3?
A technician confirms the cause on site and gives you the price in writing before any work starts.