Bryant Heat Pump (Dual Zone) only Heats on Aux and ONLY upstairs.
I need help figuring out why our Bryant Heat pump (Dual Zone) only puts out heat when the little green light is on that says aux. Also, why does it only blow upstairs? I have thermostat controls both upstairs and downstairs. If I turn on the heater using the upstairs thermostate, it seems to work fine, heats the upstairs (not downstairs) real quick. If I turn on the heater using the downstairs thermostat, it kicks on but never heats the downstairs portion of the home at all. But upstairs goes all the way to 80+ degrees! There is no air coming out of the ducts downstairs either. Seems to me like a diverter door that switches the zones must be stuck in the upstairs position. Is that physically possible? Is it possible to manually switch it's position? I'd be perfectly happy with the heater heating only downstairs because we prefer the upstairs cooler. But heating only upstairs when downstairs is 68 degrees isn't good. Any help would be appreciated and thanks for a great forum! BTW, Home is 8 yrs. old. Do you only have one system that is zoned or do you have 2 separate systems with their own thermostat? Zone systems always have issues like this. Yes you have a bad zone damper or motor. It's a single unit with a dual thermostat setup. Upstairs has a thermostat and downstairs has a thermostat. Upstairs thermostat operates the upstairs HVAC system just fine. Downstairs thermostat operates the HVAC system but it runs forever because no air comes out of the vents downstairs and all of the air comes out upstairs making upstairs 80+ degrees while not really heating downstairs enough to cause the thermostat to turn it off. I went in the attack and looked at the system. I notices it has a 3 zone computer board. I was wondering if it could be the board and one of the zones (downstairs) is bad, could I utilize that third zone to bypass the problem? How would I figure out if it's the damper, the motor or the board itself? Your zone control board sends a timed (about 20 seconds) 24VAC signal between Com2 and OPN2 when a demand is created in that zone. If you measure while someone pegs that zone stat it is much easier to check. It is going to be the damper actuator. The bad news is that they change the damper shaft regularly so replacement of the entire damper is often required instead of replacing only the actuator which would be much less work. (this drives me nuts) You can unwire the damper and press the manual release button and spin the damper shaft with channel locks to the open position untill repairs can be made if my post proves to be correct. If the damper appears to be very rusty, you may be able to clean and oil it using the release button and some channel locks. I think you guys are onto something. My Dad tapped on the damper actuator a couple of times and I cycled on the HP while he watched the actuators. They moved real slowly right after the system started up. But something seems odd here. Clearly, the actuator is sticking or failing but the dampers are both in the OPEN position when the system is off. Shouldn't they default to closed when the system is off? When activated by the lower floor thermostat, the actuator on the upstairs ducting closes forcing the air through the ducting to downstairs. This is working correctly as far as heating the right part of the home now. (so long as that actuator for the upstairs duct doesn't stick again) But when the system shuts off by thermostat, the damper doors default to OPEN which allows the heat to leave the home via the ducts and dissapate through the collector. Shoudn't they be closed when the system is off? And shoudn't the downstairs thermostat cause the downstairs damper to open instead of closing the upstairs? That would make a more sealed system when the unit is off. Is this thing installed wrong? Also, found a box from an actuator in the attic insulation. Looks like the damper actuators have been repaced before... most systems leave the dampers open during the off cycle. Actuators are a common failure. Well, I replaced the damper control module (DCM) and gave it a trial run and everything worked as it is supposed to. However, a day or so later it returned to it's old ways. Bump the thermostat up from downstairs to activate the heat pump and the DCM fails to close off the upstairs ducting which results in 90% of the heat going upstairs. It runs for hours, heating upstairs to 80 degrees and never really heats the downstairs area... I noticed I have a 3 zone circuit board and was thinking about abandoning zone 1 which controls the upstairs DCM and utilizing zone 3. Question: is there any reason why the system wouldn't work properly with zone 2 wired to the upstairs thermostat and zone 3 wired to the downstairs thermostat? (instead of zone 1 wired to the downstairs thermostat) Zone 3 is currently unused... 2nd question: Is there any indication that the thermostats could be involved here? They seem to be working as needed but I'm grasping at this point. Thanks in advance for your help. Steve Sounds like you may need a new zone board.
Related Posts:
Avg cost of trane 2ton heat pump air handler plus thermostat
avg cost of trane 2ton heat pump , air handler plus thermostathey guys im just looking to get a ballpark figure on the least exspensive trane model to the most exspensive in the 2.5 ton range incl...
Circulator pump sizing old vs new boiler strugglings to heat house
circulator pump sizing (old vs new) - boiler strugglings to heat houseHi everyone, My old circulator pump (TACO 1/8 HP, 1725 RPM, FR 48, MOD 5KH32EG129EX) was leaking and the service person replac...
Buderus system out of control any buderus experts out there
Buderus system out of control? Any Buderus experts out there?My father in law has a Buderus G115 boiler that's about three years old. He had no heat about a week ago, and the heating guy that came...
Apollo hot water heat system idea
Apollo Hot Water Heat System IdeaHello, First post here. I recently bought a house that has an Apollo Hot water Heating system. I had this same system in the rental until I lived in (across the st...
Cracked heat exchanger carrier 58sxc
Cracked Heat Exchanger? Carrier 58SXCI have a Carrier Deluxe Condensing Furnace model 58SXC (WeatherMaker). The exhaust smells and the power company tested it and said the exhaust have very high l...
