True Refrigerator Display thi / tLo: Recorded Temperatures
Thi and tLo are not alarms. On a True cabinet with an LAE control, thi shows the highest probe 1 temperature recorded and tLo the lowest. Compare them with the current temperature on a thermometer and wait for the display to return to normal.
Low: an information screen; the cabinet is running normally.
- Code
- Thi / tLo
- Maker
- True
- Equipment
- Reach-in refrigerators
- Applies to
- LAE control
What does True error code Thi / tLo mean?
On True cabinets with an LAE control, such as the T-49-HC, the control remembers the highest and lowest probe 1 temperatures it has seen. Thi is the highest and tLo is the lowest. They are information screens that someone has scrolled to, or that appear when a button is pressed. The cabinet is running normally. Staff sometimes mistake the numbers for the current cabinet temperature, which can cause worry over a reading that was recorded earlier. A high recorded value can come from a power outage or heavy loading, and a low value from a defrost or a cold spell. The display returns to the normal reading on its own after a few moments. If the recorded numbers fall outside what your food needs, that is useful history for a technician, not a current alarm.
Affected models and control systems
True cabinets with an LAE control, such as the T-49-HC. The values come from probe 1.
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
- Thi or tLo shown with a number
- The display no longer showing the usual temperature
- Staff worried about a high-looking number
- Cabinet running normally
Possible causes
Listed in True's documentation
- Nothing needs repair if the numbers are within normal range
- A high recorded value after a power outage or heavy loading
- A low recorded value from a defrost or a cold spell
- A control setting that someone changed
Other likely causes — what usually sits behind error code Thi / tLo on this control. A technician confirms which one it is before any part is replaced.
- A recorded high from a door left open during a delivery
- A recorded low from a thermostat probe pressed against the cold coil
- A reading kept from before a repair
Safe checks before calling for service
- Compare the number with the current cabinet temperature on a thermometer.
- Wait a few moments; the display returns to the normal reading on its own.
- Write the high and low numbers down if you want us to see them.
- Call us if the recorded temperatures are out of range for your food.
- Tell us the date of any outage or loading that matches.
How a technician diagnoses error code Thi / tLo
- Read thi and tLo and note the values.
- Compare them with the current cabinet temperature.
- Match the recorded extremes with known events such as outages or deliveries.
- Check the set point and alarm limits.
- Test the probe against a reference if the values look wrong.
- Reset the recorded values if the history is no longer needed.
- Judging whether recorded extremes mean a real problem takes knowing the cabinet's settings.
- A probe that records odd values needs a meter and a reference temperature.
- Resetting stored values is a control function, best done with the cabinet's own data.
Technical reference
- Document
- Commercial Refrigeration General Control Guide TEC_TM_001 Rev C, LAE p.110 Display Code Definitions
- Edition
- TEC_TM_001 | REV. C | EN, 09/3/2025, P#811072
- Models / control
- LAE control
- 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
Are thi and tLo error codes?
No. They are recorded highest and lowest temperatures.
Does a high thi mean the food spoiled?
Not necessarily. Check what caused the high, such as an outage, and judge the food by its own temperature.
How do I get back to the normal display?
Wait a few moments and it returns on its own.
Need help with True error code Thi / tLo?
A technician confirms the cause on site and gives you the price in writing before any work starts.