Split HVAC does not achieve requested temperature

A heater core is a component inside the HVAC box (located under the dash) that is heated by engine coolant. Vent temperature is increased by routing air through the heater core before it comes out of the vents. The temperature requested by the HVAC control module determines how much air passes through the heater core and how much air bypasses it. This event is called air "mixing" or "blending" which refers to the hot air and cold air ratio. Air routing through and/or bypassing the heater core is carried out by the use of a blend door and blend door actuator. Over time these two components can fail mechanically which often results in abnormal noises and improper positioning leading to undesired temperatures. Now, higher-end A/C systems with dual-zone climate control have multiple blend doors and actuators; this is how how the two different temperature "zones" are achieved. A failure with only one of the zone's blend door/actuator would result in desired temperature out of one zone's vents and abnormal temperature out of the other zone's vents. You can read more here: https://www.yourmechanic.com/article/what-is-the-difference-between-climate-control-and-air-conditioning

Air temperature is controlled by the blend door actuator, sometimes called the air mix actuator. This actuator moves a door inside the HVAC box that routes incoming air through the heater core to be heated, around the heater core to prevent being heated or anywhere in-between to achieve the proper "mix". It would be very odd to have only one extreme or the other while adjusting the temperature knob...this could potentially be a controller issue as you suggested. I think what might be more likely though is that the actuator has failed in the full-heat position resulting in cold air initially then hot air after the engine warms up (heating the heater core). In either case, the blend door actuator should first be checked for proper operation, then the inputs (circuits from the HVAC controller to the actuator) should be checked for proper signal. You can read more here: https://www.yourmechanic.com/article/how-to-repair-a-door-lock-actuator-by-marvin-sunderland

Air temperature and delivery are controlled via small actuators on the heating, ventilation & air conditioning (HVAC) box located behind the dashboard. These actuators operate doors inside the HVAC box in order to channel air through different passages to achieve the desired result. A "blend" door actuator can channel air through the heater core, around the heater core or a mix of these two to achieve the desired temperature. A "mode" door actuator can direct airflow to the ducts that lead to the defrost vent, front vent, floor vent or a mix between. When a vehicle has dual climate control (where driver and passenger sides of the vehicle can have different air temperatures) there can be multiple of actuators of each type which can make diagnosis difficult. The first step would be to retrieve diagnostic trouble codes (DTCs) from the HVAC Control Module using an advanced level scan tool; these codes help determine the location of the issue and if it's an electronic or mechanical failure. Electronic failures would include items such as HVAC control module failure, actuator circuit failure or actuator failure. Mechanical failures would include items such as actuator failure or internal HVAC box door failure. You can read more here: https://www.yourmechanic.com/article/what-components-of-the-heating-and-ac-system-are-most-likely-to-fail

Full list of Gree Air Conditioner Mini Split Units Fault Codes. When error codes appear on the Gree air conditioner indoor display, this tells the user there is an issue with the Gree AC unit. The error code displayed will inform you of the issue or problem that is occurring with the air conditioner. Knowing what the error code means and its definition will help you to understand and troubleshoot the exact Gree air conditioner part that needs to be fixed, cleaned, repaired, or replaced. You can then clean, fix, or replace the Gree part yourself and save money. See below for all error codes that can occur on Gree Mini Split AC's.
Gree Mini Split Air Conditioner Error Codes - How To Fix
Gree Viero AC Mini Split PDF Owners and Troubleshooting Manual
GREE DUCTLESS AIR CONDITIONING & HEATING SYSTEM INSTALLATION MANUAL

Gree Mini Split Air Conditioner Part Names and Locations
INDOOR AND OUTDOOR UNIT
The Gree Air Conditioning Vireo System has onboard error code diagnostics. The outdoor unit will provide status indicators and the indoor wall unit and remote control will display error codes. The following is a summary of the codes with explanations...
GREE AC DIAGNOSTIC ERROR CODES
Gree Vireo Mini Split Air Conditioner Error Code F0
Refrigerant Leakage Protection
1) Refrigerant leak(s).
2) Indoor coil temperature sensor not calibrated.
3) Refrigerant flow is restricted (ex. valve, exv, debris)
Outdoor Unit Red Light Indicator - 9 flashes and 1 sec Off
Gree Vireo Mini Split Air Conditioner Error Code E1
System High Pressure
1) Over charged with refrigerant.
2) Blocked or dirty outdoor coil.
3) Extreme outdoor ambient conditions
Gree Vireo Mini Split Air Conditioner Error Code E2
Indoor Anti-Freeze Protection
1) Low return airflow.
2) Indoor fan speed is too low.
3) Indoor coil is blocked or dirty.
Outdoor Unit Yellow Light Indicator - 3 flashes and 1 sec Off

Gree Vireo Mini Split Air Conditioner Error Code E4
Compressor High Discharge Temperature Protection
Please refer to the malfunction analysis (discharge temperature, overload) in service manual.
Outdoor Unit Yellow Light Indicator - 7 flashes and 1 sec Off
Gree Vireo Mini Split Air Conditioner Error Code E5
Overcurrent Protection
1) Supply voltage is unstable.
2) Supply voltage is too low and system load is too high.
3) Indoor coil is blocked or dirty.
Outdoor Unit Yellow Light Indicator - 5 flashes and 1 sec Off
Gree Vireo Mini Split Air Conditioner Error Code E6
Communication Malfunction
1) Communication cable is wired incorrectly between indoor and outdoor units.
2) Indoor or Outdoor control board malfunction.
Outdoor Unit Yellow Light Indicator - Continuous On
Gree Vireo Mini Split Air Conditioner Error Code E8
High Temperature Resistant Protection
1) Incorrect refrigerant charge level.
2) Refrigerant metering device malfunction.
3) Compressor malfunction.
Outdoor Unit Yellow Light Indicator - 6 flashes and 1 sec Off
Gree Vireo Mini Split Air Conditioner Error Code EE
EEPROM Memory Malfunction
Control board malfunction.
Outdoor Unit Yellow Light Indicator - 11 flashes and 1 sec Off
Gree Vireo Mini Split Air Conditioner Error Code C5
System Configuration Malfunction
1) No jumper cap inserted on the control board.
2) Incorrect or damaged jumper cap on control board.
3) Indoor and outdoor units are not compatible.
Gree Vireo Mini Split Air Conditioner Error Code Fo
Pump Down or Gathering Refrigerant Status
Optional Service Mode
Outdoor Unit Yellow Light Indicator - 17 flashes and 1 sec Off

NOTE: All of the Gree Air Conditioner Model Numbers below are applicable for the error codes on this page...
Gree AC Vireo Models: VIR09HP115V1A, VIR12HP115V1A, VIR09HP230V1A, VIR12HP230V1A, VIR18HP230V1A, VIR24HP230V1A, VIR30HP230V1A, and VIR36HP230V1A.
Gree Mini Split Air Conditioner Error Code Charts
Gree Mini Split AC Remote Control Button Names
Gree Mini Split AC Remote Control Icons Display Screen

Gree Mini Split Air Conditioner Air Filter Cleaning Procedure
Gree Viero AC Mini Split PDF Owners and Troubleshooting Manual
GREE DUCTLESS AIR CONDITIONING & HEATING SYSTEM INSTALLATION MANUAL
Need help with error codes on your Gree AC? Please leave a question below and we will be happy to help.

[PDF]PAR-30MAA - Mitsubishi Electric Australia

https://www.mitsubishielectric.com.au/.../IB_PAR-30...

Mitsubishi Electricand Mitsubishi Mr. Slim Air Conditioners. MA Remote Controller ..... Heat. 17 ~ 28 ?C (63 ~ 83 ?F). Auto. 19 ~ 28 ?C (67 ~ 83 ?F). Fan/Ventilation. Not settable. 13 ...

[PDF]PAR-31MAA - Mitsubishi Electric Australia

www.mitsubishielectric.com.au/.../par-31maa_ib_en.p...

Mitsubishi Electricand Mitsubishi Mr. Slim Air Conditioners. MA Remote ..... Heat. 17 ~ 28 ?C (63 ~ 83 ?F) .... Preset cooling temperature is higher than preset heating temperature.

My air recycle button just blinks. Also when i turn on the - Fixya

www.fixya.com/support/t26081705-air_recycle_button_just_blinks_also

6 hours ago - Not sure the heat pump is producing enough heat. Nov 04 ... Preset heat stuck at 63. ... Feb 05, 2016 ' Mitsubishi Electric Mr Slim E12C26426.

[PDF]MA Remote Controller Mitsubishi Electric PAR-21MAA ...

planetaklimata.com.ua/.../Mitsubishi_Electric/Mitsubishi_Electric_PAR-2...

Easy Maintenance Function (Only for Mr. SLIM PUHZ series) . .... 4.4.3 Automatic Cooling/Heating Display Setting . ... Monitoring the Operation Data by the remote Controller (for Mr. SLIM) .......... ..............48 . How to .... 63. 4.2 How to set rotation function(back-up function, 2nd stage cut-in function) . ... Preset temperature (. °C. ).

Hello Hottie,
start by verifying that the outdoor A/C breaker is in the on position. If it is then there is a problem inside the unit (most likely a split capacitor failure) and you should have an HVAC company help you out because that is HIGH voltage.

we have a split type gree aircon, with one (1) horsepower. it was just newly installed, around 6 months ago. we are just surprised that one when my wife turned it on, thru the use of its remote control, the indicator box on the aircon reads or flashes "F2". I detached the batteries of the remote control for severa hours and I also detached the power cord from the wall socket, but it was to no avail. it did not work. with "F2" on the indicator box, the aircon won't give cool air, it is just working like an ordinary fan. please help us.

Hi,
Here is a tip about Mitsubishi Air Conditioners and how to get the manuals for all of the mitsubishi line. The manual include both troubleshooting and installation.

Mitsubishi Air Conditioner Troubleshooting and Repair
http://www.fixya.com/support/r5643983-mitsubishi_air_conditioner

heatman101

Send your request to:

[email protected]

air conditioner can work at 0 deg C outside temp and you do not need a heater for compressor if is split system.