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Error code reference

Goodman Air Conditioner Error Code HP

Heat Sentinel

Goodman codesGoodman air conditioner codes

Heat Sentinel - wireless indoor air temperature exceeds u3 threshold.

First step from the service manual

No action required. This setting will disengage when the room temperature falls.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What HP means on a Goodman air conditioner

The HP code on a Goodman air conditioner stands for Heat Sentinel, a protective feature that monitors indoor air temperature through a wireless sensor. When the indoor air temperature rises above the programmed U3 threshold, the system activates this alert. The U3 threshold is a user-configurable or factory-set temperature limit that defines the upper boundary of acceptable indoor conditions. Once that boundary is crossed, the Heat Sentinel engages and the HP code is displayed.

This is not a fault or failure code in the traditional sense. The Heat Sentinel is a monitoring and protection function built into the system to alert users or technicians that indoor temperatures have reached a potentially problematic level. The wireless indoor sensor continuously communicates temperature data to the control system, and the HP status reflects a real-time condition rather than a component malfunction. No immediate action is required to address this code.

The code will automatically clear once the room temperature drops below the U3 threshold. This can happen naturally as the system continues to cool the space, or as outdoor conditions change. If the code persists for an extended period without the temperature recovering, it may indicate an underlying performance issue such as reduced cooling capacity, restricted airflow, or improper U3 threshold configuration. In those cases, further investigation into system performance would be appropriate.

Source: manufacturer service documentation.

Common causes of HP

  1. 01

    High ambient indoor temperature

    Wiring / connection

    The most straightforward cause is that the room or space has genuinely become hotter than the U3 threshold, often due to external heat load, doors or windows left open, or peak summer heat. The system is responding accurately to real conditions.

  2. 02

    Reduced cooling capacity

    Wiring / connection

    If the system is underperforming due to low refrigerant charge, a dirty evaporator coil, or a restricted filter, it may struggle to keep the space below the U3 threshold, causing the Heat Sentinel to engage more frequently or for longer periods.

  3. 03

    Restricted airflow

    Wiring / connection

    A clogged air filter, blocked return grille, or closed supply vents can reduce the system's ability to circulate cooled air effectively, allowing indoor temperatures to climb past the configured threshold.

  4. 04

    U3 threshold set too low

    Wiring / connection

    If the U3 temperature threshold has been configured at a value that is too close to normal operating temperatures, the Heat Sentinel may trigger under conditions that are not truly hazardous. Reviewing and adjusting the U3 setting may resolve recurring alerts.

  5. 05

    Wireless indoor sensor placement or signal issue

    Wiring / connection

    If the wireless indoor temperature sensor is placed near a heat source, in direct sunlight, or is experiencing communication issues that cause inaccurate readings, it may report falsely elevated temperatures that trigger the Heat Sentinel.

See the test procedure for each cause

Frequently asked questions about HP

What does HP mean on a Goodman air_conditioner?
HP stands for Heat Sentinel on a Goodman air conditioner. It indicates that the wireless indoor air temperature sensor has detected a temperature above the configured U3 threshold. This is a monitoring alert, not a system fault. It will clear automatically when the indoor temperature drops below that threshold.
Do I need to do anything to fix the HP code on my Goodman unit?
In most cases, no action is required. The Heat Sentinel alert is designed to disengage on its own once the room temperature falls back below the U3 limit. If the alert persists for an unusually long time, it is worth checking the air filter, verifying that vents are open, and confirming the system is running and cooling normally.
Is the HP code on a Goodman air conditioner a safety concern?
The HP code itself is a monitoring notification rather than a warning of imminent equipment failure or danger. It is alerting you that indoor temperatures have exceeded a set limit. If the space is occupied and temperatures are uncomfortably high, addressing airflow or system performance issues promptly is advisable for comfort and equipment longevity.
Will resetting my Goodman air conditioner clear the HP code?
Resetting the unit may temporarily clear the display, but the Heat Sentinel will re-engage if the indoor temperature remains above the U3 threshold. The proper resolution is to allow the space to cool naturally or to address any underlying performance issues that are preventing adequate cooling.
How much does it cost to resolve the HP code if my system is underperforming?
If the HP alert is tied to a genuine system issue such as low refrigerant or a dirty coil, repair costs can vary widely. A refrigerant recharge and leak repair typically ranges from $200 to $600 or more depending on the refrigerant type and the extent of the work. A professional coil cleaning service generally runs between $100 and $300. Replacing or cleaning an air filter is a low-cost step you can often handle yourself for under $30.

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