We've a 3.5-year-old house in subtropical FL, the system is a Carrier FB4CNP061, set up with three zones, a Honeywell HZ322 control board, Honeywell tstats, and Honeywell zone damper motors.
An HVAC tech came to analyze and fix a problem we were having. We were not getting cooling in our largest zone, and even in this dry cool winter season of 65-70 nights, 75-82 days, RH in the 50s, we were seeing indoor RH in the 70 range.
He found we had unknowingly set the system to fan ON, and not AUTO, which was circulating uncooled air 24/7. He found short-cycling happening due to what he thought was a faulty DAT sensor (installed in discharge duct about a foot away from the unit), and a closed damper caused by either being stuck or damper motor failure.
He opened the damper for zone 2, turned the system fan to run AUTO, disabled the DAT sensor (unclipped its two leads from the HZ322), and within two hours, we were cooled correctly and indoor RH was reading in upper 50s (had been 72).
He quotes a big number, the price of four steak dinners at a Ruths Chris, to furnish and install a new zone damper motor (Honeywell M847D-ZONE, for normally open dampers, $135 online).
He says the DAT can remain permanently disabled going forward, that it was not needed. I tried to get info on this and the device seems to read temp and signal shutdown if low temp goes below 30F and high temp goes above 110F.
Is his position on the DAT an acceptable one? A new sensor is $35 from Amazon, and a far easier swapout than the damper motor. Here it is: Honeywell CECOMINOD032202 FBA C7735A1000, Gray
I have studied things and can do both swaps myself.
An HVAC tech came to analyze and fix a problem we were having. We were not getting cooling in our largest zone, and even in this dry cool winter season of 65-70 nights, 75-82 days, RH in the 50s, we were seeing indoor RH in the 70 range.
He found we had unknowingly set the system to fan ON, and not AUTO, which was circulating uncooled air 24/7. He found short-cycling happening due to what he thought was a faulty DAT sensor (installed in discharge duct about a foot away from the unit), and a closed damper caused by either being stuck or damper motor failure.
He opened the damper for zone 2, turned the system fan to run AUTO, disabled the DAT sensor (unclipped its two leads from the HZ322), and within two hours, we were cooled correctly and indoor RH was reading in upper 50s (had been 72).
He quotes a big number, the price of four steak dinners at a Ruths Chris, to furnish and install a new zone damper motor (Honeywell M847D-ZONE, for normally open dampers, $135 online).
He says the DAT can remain permanently disabled going forward, that it was not needed. I tried to get info on this and the device seems to read temp and signal shutdown if low temp goes below 30F and high temp goes above 110F.
Is his position on the DAT an acceptable one? A new sensor is $35 from Amazon, and a far easier swapout than the damper motor. Here it is: Honeywell CECOMINOD032202 FBA C7735A1000, Gray
I have studied things and can do both swaps myself.
