HVAC Help

[tunatuk]

Hey guys-

Woke up this morning to heater not turning on. AC won't turn on either, nor will the fan run.

I've reset the thermostat, flipped all the breakers (inside, and at the Central unit), all to no avail.

Batteries are good at the thermostat. Any suggestions??

Doesn't appear to be frozen up at the unit either, so I'm out of ideas. Just looking to try and get this going ASAP. Going to call the landlord, but it will probably be Monday till he can get someone out here.

 

[jmcrawf1]

Fuse on the outside of the house at the outside unit

 

[tunatuk]

Fuse on the outside of the house at the outside unit

Where would this generally be? The box outside had what appeared to be a fuse, with On written on one side, and off on the other. It had something that you could pull completely out and rotate to fit either one. I assumed this to be the breaker.

If that is the breaker, where would I try looking for the fuse at?

 

[Guate_shooter]

The fuse should be in the middle of that thing that you pulled out, it shouldnt have a clear window but still have the same pill like shape, usually has a green sticker on it.

 

[kz45]

Thats just a disconnect so they can work on the unit, you could have a burnt wire/ connection, I just went through this same thing. I had a bad connection in a wire nut and it got hot and melted the wire nut away, lost connection

 

[jmcrawf1]

Where would this generally be? The box outside had what appeared to be a fuse, with On written on one side, and off on the other. It had something that you could pull completely out and rotate to fit either one. I assumed this to be the breaker.

If that is the breaker, where would I try looking for the fuse at?

The insert that you pull out has two fuses. Pull the fuses out of the insert and take them to lowes and have them tested. You can test them yourself if you have a multimeter.

 

[some_goat]

is this a package unit or a split unit ? If its a split unit , the problem is most likely going to be in the air handler or heater , depending on if its gas or electric . Unsually u can run heat without the use of the outside condensor , unless its a heat pump but dont quote me on that . Its mostly the inside unit that controls the outside and there can be several things to check . On the board inside the inside unit they have a fuse that could have went out . The thermastat may be bad or the low voltage could have a short . There can be several things can be wrong . Can evan be a float switch or a transformer issue .

 

[Yrdawg]

Is it a heat pump ??

If so try the emergency heat settint on T Stat

next look in the fan coil, blower, furnace, what ever unit you have inside...could be a 5 A fuse on the circuit board ( low voltage )

Maybe loss of power to indoor unit also

Do you have a voltage testor ??

 

[jimdana1942]

what brand unit and is it a split system? electric or gas heat? Is the thermostat digital?

 

[PrairieCajun]

Possibly burnt relays. Just had the same symptoms from lightning while out of town. Janitrol unit 20+yo. Replaced 2 relays and good to go.

 

[tunatuk]

Its a condo, and I'm on the top floor. My downstairs neighbor has her own AC unit, and I have my own as well.

I don't know if it is a heat pump, or anything really about this stuff. I pulled out the switch on the outside, and it is basically a T shape, that you rotate 180* to go on or off. on one side of the top of the T is on, the other is off. and you just line them up to the ON and OFF on the box itself.

It's a brand new unit, I'm the first resident to live in it since it was built. The thermostat tried switching on once that I heard, so I doubt it is the thermostat. I'm gonna try and check in the attic and see what I can find.

 

[Suburbazine]

If you don't have it fixed by tomorrow afternoon I could drop by and do some testing. I know next to nothing about condo units though so all I will be able to tell you is where you *don't* have power. If it's easily fixable then I can fix it, but I won't have any replacement parts.

 

[tunatuk]

Thanks Suburbazine! I'm going to call my landlord, and see when he or someone he hires can come out. If he can get here tomorrow, he's pretty handy, and might be able to fix it. If he can't do anything, I'll definitely let you know something! I have work all night tonight, and work at 4pm-4am again tomorrow night!

I appreciate the help!

ETA: It's a normal AC unit. It's just like any other AC unit that I've ever seen...

 

[tunatuk]

Just spoke to several people out here, and I was recommended to change the thermostat. Going to Lowe's first thing in the AM and buying one, and gonna swap that out. If that doesn't work, I just found out my friend's uncle has an AC/heat business, so I'll give him a call and see if he can get out here pronto.

 

[Railrunner]

no doubt, guaranteed from your discription it's the TRANSFORMER!!!!!!!

 

[some_goat]

A way to see if it may be the transformer is to take the batteries out of the thermostat and see if it goes dark . If it does and the unit has power than i would take a look at the transformer .

 

[Suburbazine]

Turn off ALL power to the unit before you touch the thermostat. If you short a pair out, you're looking at a control board and transformer replacement. Also determine if you have single stage or dual stage HVAC, a single stage thermostat cannot run a dual stage system.

 

[tunatuk]

A way to see if it may be the transformer is to take the batteries out of the thermostat and see if it goes dark . If it does and the unit has power than i would take a look at the transformer .

My thermostat is battery only. It doesn't not use any power from the AC unit, from what I understand.

 

[Yrdawg]

More the norm these days in non HP apps

If there is no wire ( usually blue or black ) on the C terminal its 99% battery only

 

[mikeinneworlean]

There is also a small fuse (10-15a) that protects the unit's controls from a thermostat short.
Typically on the side of the unit is a control box with the thermostat wire leading to it.
Check that - Good luck!