I just moved into a new multi-family house with central heat/AC and the 3rd floor bedroom doesn't seem to warm up very well. When the thermostat is on, I don't feel hot air blowing in from the vents in that bedroom. The bathroom vent upstairs seems to blow lots of warm air and all the vents on the 1st floor apartment as well as the 2nd floor seem to work.

There are 2 thermostats per floor, with 2nd and 3rd floor being a single apartment duplex.

I looked at the setup in the basement and saw these red lights - does that mean the system is not working correctly? How can I diagnose?

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  • Is it a solid red light? Does it ever turn green (in 30 seconds or so) ?
    – JPhi1618
    Feb 1, 2019 at 18:57
  • solid red light Feb 1, 2019 at 22:44

1 Answer 1


I had one of these units in a two story house, and the red LED means that zone is closed, a green light means that it is open. So, for the panel on the left, the system is calling for heat, and only the Zone 3 damper is open (so the Zone 3 thermostat is the one calling for stage 1 heat.

If any of the zone lights are blinking (may blink amber color), then there is a problem with one of the damper motors.

Here is a link to a PDF manual if you want to know more about it, but once they are set up, they don't require any maintenance. You can test all the functions to troubleshoot things, but right now it seems to be working correctly.

  • so the panel on the right - it has 3 greens but no light for heat - what does that mean? Feb 1, 2019 at 22:44
  • I’m not sure if it’s a setting you can change, but if no heat or AC is called for, the zones are normally opened. So after the call for heat is done, all dampers open up.
    – JPhi1618
    Feb 1, 2019 at 22:58

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