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First Company CDXQ Fan Coil System not getting hot water

hvac_help Member Posts: 3
We have a First Company CDXQ fan coil unit and is not getting hot water or heating. Hot water heater was just replaced but the hot water isn't getting to the coils in the fan coil unit. I already bled the air out of the system but the pump doesn't seem to be pulling hot water to the system. 

The central heat went out at the same time as the water heater.  The new water heater is in but the central heat isn’t working. 

Does the system need a vacuum? When i bled all of the air out of the system I did not turn off the hot water in (#1 in the instructions)



  • hvac_help
    hvac_help Member Posts: 3

  • Jon_blaney
    Jon_blaney Member Posts: 322
    Is the pump running? Is there air in the DHW? If pump is running, purge again according to the instructions. Make sure the thermostat is set to heat.
  • hvac_help
    hvac_help Member Posts: 3
    The pump felt like it was running.  But isn’t pulling hot water at all.  I bled it with it on for around 5 minutes.

    Everything else in the house is getting hot water just not this system. Went to touch all the copper lines and they are all cold.
  • Jamie Hall
    Jamie Hall Member Posts: 23,635
    Bleeding and urging are two very different things. By purging is meant running a good deal of water through the system under pressure -- typically one purges just one zone (in this case the air handler and its associated piping) with a connection to your domestic water directly, and discharging into a handy drain.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Ironman
    Ironman Member Posts: 7,397
    Purging is also accomplished by having either the supply or return line shut off (depending upon the purge arrangement) so that flow is only moving from one side to the purge valve.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.