1. Sunday afternoon we get home and the house is 84 degrees. Ground floor unit fan not running, obvious Texas summer time blown capacitor.
2. Call the repairman for a Monday morning appointment. Sure enough my assumption was correct. Up and running in thirty minutes after a hefty bill.
3. Mid-day Monday all the rooms in the house are cool, except for the master bedroom, which is getting warmer. It got up to 79 during the day and cooled off during the night since we opened the bedroom door to let some of the cooler air from the living room in.
4. This morning, in between work meetings, Im able to shower and get ready for the day. Drying off, I notice there is cold air pumping into the master bedroom/bathroom.

Spoke to technician and he made a guess that damper in the duct that feeds the bedroom/bathroom must have shut during the capacitor episode. What he couldnt explain was how the damper opened backup. Could it be a fully charged and functioning capacitor provided enough juice to re-open? Maybe a pissed off relay or switch in the unit? Im just gueesing here. Would be nice if a good Ag could help to explain.

Thanks,
Tim C/O 2000

pillow said:

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1. Sunday afternoon we get home and the house is 84 degrees. Ground floor unit fan not running, obvious Texas summer time blown capacitor.
2. Call the repairman for a Monday morning appointment. Sure enough my assumption was correct. Up and running in thirty minutes after a hefty bill.
3. Mid-day Monday all the rooms in the house are cool, except for the master bedroom, which is getting warmer. It got up to 79 during the day and cooled off during the night since we opened the bedroom door to let some of the cooler air from the living room in.
4. This morning, in between work meetings, Im able to shower and get ready for the day. Drying off, I notice there is cold air pumping into the master bedroom/bathroom.

Spoke to technician and he made a guess that damper in the duct that feeds the bedroom/bathroom must have shut during the capacitor episode. What he couldnt explain was how the damper opened backup. Could it be a fully charged and functioning capacitor provided enough juice to re-open? Maybe a pissed off relay or switch in the unit? Im just gueesing here. Would be nice if a good Ag could help to explain.

Thanks,
Tim C/O 2000

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My air dampers can be adjusted, however, they're manually adjusted from a lever where my ducts hookup to the plenum above the furnace/coil on my vertical stack in the attic. They have a wing nut underneath the adjustment that can be loosened to open/close the air damper and then tightened after the adjustment to make sure they don't move again.

Not sure how they can move from just shutting down from a bad capacitor. Although your air dampers may be digital??

ours are electrical but my knowledge of electricity is limited to my A in sophomore year EE.

Op, are you on a zoned system?

Col. Steve Austin said:

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Reading up a bit on the electrically operated dampers, I'm assuming you have the following:

Quote:

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2-Wire Dampers (Power-Open/Spring-Return or Power-Closed/Spring-Return): These use 24V to drive the motor in one direction, and an internal spring to return it to the default position when the power is cut.

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It could have simply gotten stuck closed and then eventually opened after a number of on/off cycles (air flow / no air flow). Just a guess.

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I've had this happen multiple times with dampers.


You can go up there, open it, and disconnect the wires so it doesn't close again. This leaves the open all the time. Not the most cost-efficient method, but will get you AC in the meantime, until you're ready to replace the damper motor.