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May 17, 2026

VRV Service Call: Solving the J2 Error Code with Roman Baugh

Join Roman Baugh as he takes you on a real-world VRV service call, tackling a tricky J2 error code on a multi-module V3 system — and uncovering much more than expected along the way.

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Does Setpoint Lead to Freezing?
Does setting a thermostat too low cause an air conditioning system set in cool mode to freeze? The answer is no, at least not directly. However, low evaporator load (low return temperature or low airflow) and low outdoor ambient temperature can lead to evaporator coil freezing. Low indoor setpoint can lead to low return air […]
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Fan Blade Shroud Depth
When a system has abnormally high head pressure (high condensing temperature over ambient) and compression ratio, one of the easiest things to look for is a dirty condenser coil. More often than not, that will be the cause. However… There is another category of issues that can cause high condensing temperature (high head pressure), but these […]
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The "Bad" Contactor That Wasn't
I wanted to share a recent “rediscovery” with you out of pure humility. I call it a rediscovery because it’s a basic fundamental I already knew, but it just hadn't come up recently enough to be top of mind until the other day. I found myself troubleshooting a single-pole Mars 91311 contactor. I had voltage […]
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