True Refrigerator Error Code dA: Door Switch Alarm
DA on a True cabinet with a Dixell controller means the door has been open longer than allowed, or the door switch says it is open when it is shut. Close the door firmly, check the gasket, and watch whether dA clears. If it stays on, a technician should check the door switch and wiring.
Low: the cabinet keeps cooling, though a stuck switch can raise wear and temperature.
- Code
- DA
- Maker
- True
- Equipment
- Reach-in refrigerators
- Applies to
- Dixell controller
What does True error code DA mean?
DA is the door switch alarm on a True cabinet with a Dixell controller, shown for example on the T-49-HC. The control reads the door switch to know when the box is being opened. If the switch reports open for longer than the allowed time, the control raises dA. The same message appears when the switch is reporting open while the door is actually shut. The cabinet usually keeps cooling, but fans and lights may follow the switch, so a stuck switch can affect temperature and add wear to the compressor. A door that really is ajar lets warm air in and the evaporator ices up faster. When dA clears as soon as the door is firmly closed, the door was the cause. When it stays on, the door is not seating or the switch signal is wrong.
Affected models and control systems
True cabinets with a Dixell controller, such as the T-49-HC.
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
- DA on the controller display
- A beeping alarm until a button is pressed
- Interior light or fans behaving as if the door were open
- Frost building on the evaporator or door edge
Possible causes
Listed in True's documentation
- A bent hinge or worn gasket keeping the True door from closing fully
- A door switch that sticks in the open position
- A broken or loose wire at the Dixell door switch connection
- A pan or product tray that props the door slightly ajar
Other likely causes — what usually sits behind error code DA on this control. A technician confirms which one it is before any part is replaced.
- A door switch plunger gummed with spilled syrup so it no longer rebounds
- A magnet or switch lead moved out of line during a door adjustment
- Water from washdown in the switch connector
Safe checks before calling for service
- Close the door firmly and look for anything keeping it from seating.
- Check that the gasket is not folded back or torn.
- Press a button to silence the alarm.
- Watch the display for a minute to see whether dA clears when the door is shut.
- If it stays on, note whether the interior light or fans act as if the door is open.
How a technician diagnoses error code DA
- Check how the door sits and closes against the gasket.
- Look at the hinge and latch for sag or looseness.
- Watch the door switch input at the controller as the door opens and closes.
- Test the switch with a meter for continuity in each position.
- Inspect the switch wiring and connector for a break or loose pin.
- Replace the switch or lead after the test shows it is the problem.
- The door switch circuit connects to the Dixell controller, which sits behind a panel beside powered wiring.
- A switch that sticks can leave fans and lights running and shorten compressor life if not corrected.
- Adjusting or replacing a door means lifting a heavy door and re-setting the seal.
How error code DA differs from similar codes
True lists a separate door open alarm called do for cabinets with an LAE control; dA is the Dixell version.
Technical reference
- Document
- Commercial Refrigeration General Control Guide TEC_TM_001 Rev C, Dixell p.96 Display Code Definitions
- Edition
- TEC_TM_001 | REV. C | EN, 09/3/2025, P#811072
- Models / control
- Dixell controller
- Section
- Electronic Control (with Display) - Display Code Definitions: Carel p. 74, Danfoss ERC/ETC p. 87, Dixell p. 96, LAE p. 110
- 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 True reach-in refrigerator error codes
Does dA mean the cabinet stopped cooling?
Usually not. It keeps cooling, though a stuck switch can affect fans and temperature.
Why does dA stay on when the door is closed?
The door may not be seating, or the switch is telling the controller the door is open.
Is dA the same as do?
They mean the same thing on different controls: dA is Dixell and do is LAE.
Need help with True error code DA?
A technician confirms the cause on site and gives you the price in writing before any work starts.