My new comfortsense 7000 thermostat has an error reading "HVAC Error Detected". My installer checked the L input and everything on the HP and furnace checked out fine. Installer was on hold with Lennox for almost an hour (sitting at my dining room table, so I witnessed it myself), but he still doesn't have an answer. So I thought I would be "pro" active and ask you guys if you have any idea as to what may be the cause of the error message. Could it have something to do with the outdoor sensor that is wired but not yet physically installed?
The "HVAC ERROR DETECTED" only pertains to an LSOM error. The outdoor sensor comes factory default set to NO. It would not give this error. Looks like the error is coming from the LSOM working properly. He needs to check the outdoor unit for a problem. This is the notes from Lennox on that error:
"L" input from the equipment is used to notify the user of an equipment
fault by displaying HVAC ERROR DETECTED" when one of the following
conditions exist:
L" terminal is activated with 24VAC and Y1 has been activated
for 5 minutes, OR,
LSOM error signal is detected on L" input and Y1 has been activated
for 5 minutes.
NOTE − If system is in battery mode, the L terminal is not functional. The
L input is used for diagnostic information purposes only, it is not intended
to provide equipment protection.
Have him check the heat pump for proper installation and sequence of operation and disconnect the "L" terminal and restart system. If all goes well hook the "L" back up and try again. Also make sure that the tempsensor is set to no in installer setup until the sensor is installed.
Thanks, Socal. He did check the outdoor unit and said it was running perfectly. He was reading the programming manual so he did check the L terminal, although I am not sure if he disconnected it and restarted the system.
If he is still having problems with it have him try the LSOM installation verification steps described below as well:
LSOMInstallation verification
To verify correct LSOM installation, two functional tests
can be performed. Disconnect power from the compressor
and force a thermostat call for cooling. The red trip LED
should turn on indicating a compressor trip as long as
24VAC is measured at the Y terminal. If the red LED does
not function as described, refer to table 8 to verify the wiring.
Disconnect power from the compressor and 24VAC
power from LSOM. Remove the wire from the Y terminal of
LSOM and reapply power to the compressor, allowing the
compressor to run. The yellow alert LED will begin flashing
a code 8 indicating a welded contactor. Disconnect power
from the compressor and 24VAC power from the LSOM.
While the LSOM is off, reattach the wire to the Y terminal.
Reapply power to the compressor and 24VAC power to the
LSOM; the yellow alert LED will flash the previous code 8
for one minute and then turn off. If the yellow LED does not
function as described, refer to table 8 to verify the wiring.
Table 8 will be in any manual with a LSOM installed.
Last edited by socalhvacguy; 07-17-2008 at 07:29 PM.
Reason: added info
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