Attachment 47743Hi -Looking for help on how to replace my attic fan or maybe just the motor?I know one of the boxes in the image is the thermostat and I'm not sure what the other box is which has that copper looking relay? I think the box with the doorbell is where the fan gets power.I was told by a HVAC Tech that the fan is getting power, but I've not tested with a voltmeter myself. I not quite sure where the breaker would be for this and I'm also not sure if I can remove the fan motor from inside or do I need to do this from the roof? I'd guess I can reuse the fan blade.Please keep in mind I've VERY GREEN when it comes to electrical...



Maybe I just need this? http://www.amazon.com/gp/product/B00...f_rd_i=desktop

Forgive me none of your pics are usable. Please attach the pics using the "Go Advanced" button below.

Also, your post does not make sense s it is written. Can we start with what the failure is, please.

If the fan is failing to run we need to look at the circuit feeding the fan and whatever controls the fan's operation. For example, you said that a HVAC tech said the fan was getting power. What is the voltage at the fan supply? Is it 120 VAC?

Does the fan have a capacitor start? If so, can you spin the fan blade manually and then turn the fan on and get it to work? (bad capacitor). Do you see any evidence of a burnt motor?

If the fan is controlled by a thermostat, is it part of the fan or one of the boxes that are on chord? Is the thermostat getting the correct mount of power (usually 24 VDC).

If the thermostat is fed by the output of the bell, you need to make sure that the output of the bell step-down transformer is correct.

That will get you started.

Attachment 47744

Ok pics should be attached -

The failure is that the fan is failing to run. I believe this is 120VAC, but I don't have a multimeter at the moment (just ordered one off Amazon).

I don't think it has a capacitor start and I have not tried to spin it yet. I will look closely and see if there is evidence of a burnt motor tonight.

Thermostat box on chord. Not sure on power until I get meter.

Not sure what "bell step down transformer" is but I'm guessing it is the other box on the cord. Hopefully u can see the pictures now?

A step down transformer takes the 120 VAC source and drops it down to 24 V.

Just curious, but does bell work properly?

Why did you order the meter from Amazon, you can pick up a meter for about $15.00 at just about any hardware store and not have to wait for it.

Is the fan controlled by an internal thermostat or from a thermostat relay?

Ok remember I'm extremely GREEN here -

The doorbell does work. I have that in the picture because I think this is where the fan ends up getting its power from this junction box. I will double check that. That is one of my issues. I have not figured out where the breaker is for this attic fan.

I only ordered from Amazon because it was just an add on for some other stuff. You are correct, I could have just picked one up anywhere.
(and i'm working until 9pm est today)

As far as if the fan is controlled by an internal thermostat or a thermostat relay, I'm not sure. All I know is that the box has the little white dial with temp reading on it so I'm guessing this is a thermostat relay? Sorry for green answer.

Those are 120VAC fans. Home Depot carries them in the roofing area. They can be easily replaced from inside. The thermostat has the dial. Never saw one with a relay or a start cap. Make sure to reconnect the BX cable and put a cover on the junction box. These are both NEC violations.

The fact that the BX is out of the metal box but the wires are still connected tell me this was never installed correctly. Have you actually opened the "box" which likely contains the thermostat?