This web page provides recent example(s) of derated systems that were diagnosed by our MCerberus® HVAC Monitoring system. We provide examples as they occur so please feel free to come back and observe real-life examples. As of 2020 the following statistics apply:

  • We have had units in the field with over seven (7) years of run time
  • In a given year approximately 15 to 20 percent of our monitored units issue an alert. In the vast majority of these cases the Users of the living space are unaware that there is an issue with their HVAC system.
  • While the most common failure mode is due to low refrigerant levels (AC mode) our systems have captured a number of units that are “short cycling”
  • The System includes a water sensor that detects and alerts the User to water in the condensate drain pan and/or drain line.
  • Our MCB-404 series unit includes delta P monitoring of your HVAC filter

2019.12.10 On / Off Cycle Issue (Short Cycling): Extreme example of a unit short cycling

2020.04.04 On Off Cycle Issue

2020.03.22 Refrigerant Leak (repaired): Note the large decrease in run time AFTER the unit repaired.


2020.03.29 Refrigerant Leak (repaired) 

2021.06.01 RTU running all the time 


2021.07.16 Starter Capacitor Failure: Mobile App showing the User the Operating Summary of their unit when the starter capacitor on their unit failed. While there was minimal lead time provided to the homeowner – the User understood that something was definitely wrong and had no qualms about making a service call.



2021.09.10 Dirty HVAC Filter: Extreme example showing the delta P difference when a Lennox “Change Yearly” HVAC Filter was replaced. In this case, the blower fan current dropped by approximately ten (10) percent with the new filter.