How to tell if an EEV needs to be replaced vs low refrigerant
It's me again, https://www.reddit.com/r/heatpumps/comments/1tombrq/humidity_spiking/
I'm located in Queens, NY, and we just experienced a pretty brutal heat wave, which is why I was able to troubleshoot as much as I have.
Now I have a better description of my issues with my 1st and 2nd floor mini splits. I sent this information to AI chatbots and I'd like to double-check their conclusions instead of blindly trusting them.
The following intake/exhaust temperatures were taken with a probe thermometer. The coil temperatures were taken with an IR thermometer. The line set temperatures were measured on the surface of a 6" section of exposed copper pipe with a FLIR camera. These temperature readings were taken after the system had been on for about an hour.
1st floor - taken around 1:20 PM @ 95°
All indoor units were set to 70°F/cool mode/auto fan speed. Around 10 minutes after I turned the indoor units on, I noticed that the kitchen and bedroom liquid lines frosted for about a minute, then thawed. They didn't refreeze for the 20 minutes I was outside. The living room liquid line set did not freeze.
Both Claude and Gemini agree that Fujitsu's liquid line sets are supposed to be colder than their gas line sets - exactly the opposite of my Mitsubishi (attic) system, which I currently don't have any problems with.
- Outdoor unit - Fujitsu AOU36RLXFZ - installed spring 2014
- Intake temperature - 93.9°
- Coil temperature - 104.9°
- Exhaust temperature - 104.5°
- Ambient temperature - 95°
- Kitchen - ASU12RLF
- Intake - 81.6°
- Coil - 57°
- Exhaust - 68°
- Liquid line set - 64.8°
- Gas line set - 77.7°
- Bedroom - ASU7RLF
- Intake - 80.4°
- Coil - 60°
- Exhaust - 72.6°
- Liquid line set - 64.1°
- Gas line set - 73°
- Living room - ASU18RLF
- Intake - 82.2°
- Coil - 82°
- Exhaust - 80.9°
- Liquid line set - 54.1°
- Gas line set - 89.2°
Issue: Living room does not cool off. Claude and Gemini both think I need to replace the living room's EEV. I have not tested the EEV with a multimeter yet, I want to look up where it is in the outdoor condenser before I tinker around.
2nd floor - taken around 10:20 PM @ 85°
Around 10 minutes after I turned the indoor units on, I noticed that the 3x bedroom liquid lines frosted for about a minute, then thawed. They didn't refreeze for the 20 minutes I was outside. The family room liquid line set did not freeze.
- Outdoor unit - Fujitsu AOU36RLXFZU - originally installed spring 2014, replaced summer 2022 or 2023
- Intake - 82.7°
- Coil - 88.7°
- Exhaust - 93.7°
- Ambient - 85°
- Bedroom 2 - ASUH07LPAS - replaced summer 2022 or 2023 - set point 70°
- Intake - 72.5°
- Coil - 46.2°
- Exhaust - 45.6°
- Ambient - 75°
- Liquid line set - 66.6°
- Gas line set - 58.7
- Bedroom 1 - ASU7RLF - set point 68°
- Intake - 70.5°
- Coil - 47.4°
- Exhaust - 51.8°
- Ambient - 74.8°
- Liquid line set - 65.2°
- Gas line set - 74°
- Main bedroom - ASU9RLF - set point 68°
- Intake - 80.4°
- Coil - 60.6°
- Exhaust - 69.8°
- Ambient - 81.5°
- Liquid line set - 63.9°
- Gas line set - 76.7°
- Family room - ASU12RLF - set point 70°
- Intake - 84.9°
- Coil - 84.9°
- Exhaust - 83.3°
- Ambient - 82.2°
- Liquid line - 58.6°
- Gas line - 82.8°
Issue: Main bedroom takes FOREVER to cool off - sometimes it never reaches the set point, it'll be around 70° by 9 AM. I've noticed that I need to run all 4 indoor units in order to get all of the rooms to cool off. If I don't run the family room AC, the main bedroom almost immediately starts spitting out warmer air.
Claude thinks I need to replace the EEV for both the main bedroom ("partially open") and the family room ("fully closed").
Gemini insists that I'm low on refrigerant and that mini splits act weird (7k BTU units are given refrigerant first, then the main bedroom, and the family room is starved) when there's low charge. I disagree with Gemini, I've had low charge in the 2nd floor system before - none of the rooms cooled off when this happened.
