[hdarmawan]

I could use help troubleshooting my house's HVAC.

After yesterday's earthquake, the fan (not ceiling fan) unit just stopped working, thus, the ac and also the heater doesn't work either.

What could cause this ? Is there a anti-earthquake mechanism that's been triggered in the unit making it disabled automatically ?

I have checked the breaker, and it was still in the ON position. I have also swiped it to OFF and then ON again just to make sure.

Any ideas ?

Thanks !!!

 

[Yoyizit]

Is there a anti-earthquake mechanism that's been triggered in the unit making it disabled automatically ?

This failure could be a coincidence or fragility and/or poor workmanship.

You'll have to find the open circuit by tracing with a voltmeter from where the power enters the unit's circuit breaker inside the CB panel and go downstream from there. Watch out to not cause an arc flash in the CB panel by shorting anything.

If everything is dead then the fault is pretty far upstream and it should be easy to find. If only some HVAC stuff is dead then you need the HVAC schematic and tracing it can get pretty tedious.

You might also check for this complaint on the Web using your make and model, and there might be a Technical Service Bulletin on this problem from the manuf.

 

[biggles]

check the transformer in the furnace section for a black circuit breaker on the side of it.

 

[hdarmawan]

- Thank you for all the input guys.

 

[Joe F]

Just a theory:

Maybe the earthquake caused a voltage spike that popped the fuses at the service disconnect.

 

[hdarmawan]

All,

Problem fixed.

I went to the attic to check the unit, and did 2 things.
- Unplug the power cord and plug it back in.
- There was a button (don't know what is for cause there's no label on it) that I pressed - kind of a reset button.

When I turn on the fan... yipeee, fan turned on !

But then not certain which of the 2 above actually fixed it.

 

[Yoyizit]

- Unplug the power cord and plug it back in.
- There was a button (don't know what is for cause there's no label on it) that I pressed - kind of a reset button.

The first thing you did does the same as flipping the breaker.
I'd guess the second one fixed it and I guess along with Mr. F that there was a voltage spike or dropout or some other power irregularity due to the earthquake.
It could have been a temp. overload miles from your house.

Sounds like your protection circuitry for your HVAC is doing its job.