My Carrier A/C suddenly stopped this afternoon. Nothing is working.

It got hot, so I went to look at the thermostat and found a dark, blank screen that didn't react to any buttons. I popped it off and put batteries inside - we've had the house for almost exactly a year and I have never popped the thermostat off - it did not have batteries before. The batteries caused it to light and I could get the buttons to do what they're supposed to do, but the A/C never came on, not even as fan and when I pulled the batteries back out, the screen went back to blank.

I've tried flipping the breaker and the breaker-like override by the unit, with and without batteries and nothing has worked. It's Florida and it's hot. Any help would be appreciated.

Thanks

 

Is everything else electrical working in the house,i.e. Range, dryer etc?do you have a multimeter?

 

Check the fuse on the control board in the furnace.

 

I have a multimeter, but haven't really used it. As far as I can tell, everything else is working. In fact the dryer is running, as it has done a hundred times before

 

Could you point me in the direction of the fuse? There's a unit inside and a unit out, both of which I'm having trouble finding on the Carrier site

Thanks

 

The fuse would be on the inside unit (air handler). There will be a circuit board and the fuse will likely be an automotive plug-in type fuse. Note that not all units have a fuse, so it's possible that yours doesn't, but it's worth checking. If you find a fuse and it's blown, replace it. However, it's very possible that it will blow again. Fuses protect against over current conditions. Unless whatever caused the fuse to blow is corrected, the replacement fuse is likely to blow again.

 

I don't have any doors, only panels. My instinct is to take out the center, but it's a big L-shape that wraps around the one w/ pipes. Any guidance?

 

It should be in the blower section.

Hard to tell from the pic.

 

I reoriented the picture.... I think the right direction. I can't it light enough to see what's at the bottom. It looks like an oil burner.

I don't see any condensate drain line or overflow pan but a likely problem is a drain clog and an overflow switch has shut down your system.

 

Fuse looks fine, but that doesn't mean anything. It was the top (easier to get off section) If anyone wants to tell me how to check it w/ my multimeter... though it might be easier to just run to HD.

There is a condensation system. Now that you remind me, the realtor told me to pour vinegar in it once a year, but I haven't. Would a clogged line (because I didn't pour vinegar in it) cause the thermostat to go bank, unless there's a battery in it?

Everybody, thanks... I appreciate the help.

 

Yes.... and even if you did have a battery stat the system would still shut down. This is to keep from the condensate from overflowing and causing damage.

There should be a switch, usually white, somewhere in the condensate pan or line.

 

When I put the batteries in, the thermostat lit-up and stayed lit. I poured some vinegar in after your first suggestion, but that didn't cause anything to happen. (Didn't expect it would, but I looked)

The drain goes down into the box that houses the return. I assume it goes into the slab or somewhere. I'm not finding a way into the stand. There is a red valve on the line from the unit to the cleanout (in which I poured vinegar), but nobody's touched that.

 

You will need to check into the thermostat further. Some use the system for power and cannot have batteries in at the same time.

Take more pictures for us.

 

You wanted pics... glad to oblige... appreciate the help.

First is the above-box drain system. Second is the wiring stuff. Third is the closed thermostat, followed by the open.






Thanks

 

Just realized that the drain pipe which comes out by the outside unit is actually piped from the inside. Pretty sure it was dripping normally earlier and there's still a bit of a puddle, five hours or so after the a/c stopped working.

 

Clarifying info on the thermostat...

Everything was fine, then it got hot. Walked over to look at the thermostat and saw the 3"x3" screen was dark and blank. Touching buttons did nothing.

Popped the cover off. Noticed there were no batteries. Don't know why anyone would have taken the batteries, but I put a couple in. This allowed the thermostat to light. It told me the current temperature and the setting. When I pushed temp-up, temp-down & fan, the proper things occurred on the screen, but the a/c did nothing at all.

I've since removed the batteries because I'm thinking it's getting juice from the system and when it lights, it'll mean the unit is fixed.

Again, thanks for the suggestions and help.

 

Pictures really do say it all.

OK...... here's the picture I really need.... just the wiring area. Big and as bright as you can make it.



========================================================
I need your help here.... in this pic the arrow is pointing to two black wires. That looks like the A/C condensate float switch we are looking for. See if you can see where they connect.
At the board end.... I'm guessing you'll find one wire to the R terminal and one to a red wire.



I'll be online tonight until approx 1AM so we should be able to get you going.

 

Appreciate that! The no-seeums make opening windows at night a PIA.

On one end (not the arrowed) the wires go into that little white pipe you see on the right. There's some kind of end that lets them go through. On the left (of the pic) they go between the unit and the wall. When you wiggle them, they feel like they're less than ten inches until the connect to something, but I'm having a hard time seeing what and nothing else wiggles.

Also to clarify on my reply to @shaggsje: I shined a light through the fuse and the filament looks intact.

Forgot to post pic



(Can't find how I can reorient pic)

 

Moved some boxes, got a better light and thought about it a little more.

The wires are taped. That's why they don't wiggle and they go to the top, where they're fed through and go into the brown conduit. I'll go look again to see if I find where black goes, but wanted to give this update. ASAP

Update.

Nope. They don't go into the multi-wire cable. Instead, they go between the housing and lining. One you see connecting at the top of that photo. The other is wirenutted to a couple of others, off to the side.

 

I run multiple picture programs so I can change, spin, resize, etc. pics from all over DIY.

We're getting close here. I took your picture and labeled it. Now it's your turn Sherlock.

Look at the picture. See the red R. Now look at the black wire attached to it. That black wire should be the same as one of the ones that I had you look for. The other black wire should connect to a red wire in the cable with the yellow arrow. That is the cable that goes to your stat.



You do have a float switch. It is attached to those black wires. It interrupts the red power wire to your stat. You need to find out why the float switch is open. It's either stuck in the up position or the pan inside that unit is full of water.

 

The red R is the one I described as connecting at the top of the pic. It comes up and goes directly to the bus. The other goes off to the side, where it's wirenutted to a white wire which comes out of (goes into) a two-line cable. The other wire in that set is red and it's nutted to two other red/pink wires.

The cable with the white and red goes up and out the top, then probably to the stat.

At the other end (back to the bottom), the wires run into this little white pipe that goes into the unit, nowhere else. The drain which is piped outside (and I believe was dripping or had an obvious and regular puddle at the end, when I first started looking for the problem. I didn't specifically look at the drain, but I didn't notice anything different) is that white pipe sleeved in black with the red valve. Off to the edge of the pic, you see the cleanout stubbing up and the line goes into the return box, sealed around with foam, then I assume it goes directly outside (though you're the expert and I don't know)





Edit

I just read where you said "pan inside".

Would I take off the small panel which has all the pipes or it looks like I might be able to pipewrench off the out-pipe, but haven't tried?

 

I added a blue line to show you where the water line will be. That stub up thing is the float switch. Shown in the link.
Safe-T-Switch SS2 - RectorSeal

The line with the valve (and I have no idea why there would be a valve in it) is the one that's clogged.

 

Thanks. You said you could give me to 1. I appreciate it.
Now, I'll go see what I can break. Let you know what I find.

Thanks

---
Update

I just ran a little hand snake down from the cleanout. Feels like I may have go to the elbow under the slab, but I was having trouble turning, plus when I do, the snake's only so long.

Reason for this update is to let you know that the snake came up moist, so I'm thinking there's water in the pipe. Of course, after snaking to the first elbow, I looked at the thermostat and flippid the breaker. When the float valve opens, will the thermostat automatically light?

 

I'm a night owl.

 

So am I...

I tried running the snake from the other end. Because it's one of those cheap hand-cranked ones, it was giving me trouble turning to under the slab, but when I pulled it out, maybe a cup of rust-colored water came with it and it continued to drip. So, I tried pouring hot water down the cleanout from inside the house and it came out clean from the end of the pipe. Maybe it was a little more tricklely than I poured it in, by the time I got to it, but there was water coming out.

The thermostat still didn't light. I flipped the breaker which did no good. The thermostat stayed dark. Then, I put batteries in it and told it to run the fan, which didn't work.

Is there a trick to resetting the thing or do I need to come at it from the other side?

Thanks

 

The float circuit is normally closed and when the float is raised from water.... the circuit is opened. You can try shorting the two black wires together and see if the A/C restarts. Don't let those wires touch ground or you will blow a fuse.

It is possible the float is stuck. Tapping on the top of that fitting may release it.

Usually snaking is not very effective. Some use a shop vac outside on the drain line and suck the crap thru.

 

Before I saw your most recent reply...

I pulled-out the L-shaped cover. I haven't taken it totally off because there's an awkward screw behind the exterior float valve pipe. But, I pulled it out enough to see down from the top and there's not much water in the pan. It's probably been evaporating in the hot, but I stuck a dowel down and it's only like half an inch. It's also clean. I don't know where that rust-colored water came from on the outside. It seemed a little thicker than normal, so it might have been something else. I don't know. Ordinarily when I see water out of that pipe it's clean. Either way, right now, the pan on the inside is nowhere full (unless there's some kind of overflow where the water under the float valve would be higher than the water to the more easily accessible far side)

 

That did it!!!

I tapped the float valve pipe a couple of times with a big screwdriver. The LED indicator light tube lit. The thing started humming and the fan-only came on!

Thanks! You helped me make my house more comfortable and at least saved me a service call right now. Though, I don't know why the thing got stuck.

Many thanks!!!! You've been a lot of help and I appreciate you helping me into the night.

 

It got stuck because the water level rose to a dangerous level inside the tray and caused it to activate. It's supposed to reset by itself but can get stuck from grunge buildup.

You're welcome.

 

Again, many thanks!

I'll try your suggestion of sticking the Shop-Vac on the end to get rid of any remaining clogging in the morning, after the neighbors are up.

Super-duper thanks!

 

HELP AGAIN! Please! Somebody! Anybody!

I left the top cover off last night and the L-shaped panel loosened because it was late and I wanted to look inside today.

This morning everything seemed right, but the last hour or so it hasn't been cooling off. The temperature has been getting warmer. The a/c was still running, but the temperature wouldn't go down and the air coming out wasn't very cold.

I got my dowel and was ready to check the water level in the interior pan, when I discovered everything inside iced-over like a freon leak, except this is everything including wires.

I'm near the coast of Florida. I guess theoretically by not putting the insulated covers back, I let too much humidity into the thing, but that doesn't really sound right. Right now, I have it turned-off, hoping the ice will soon melt in the 80-something temp.

Any suggestions or help would be appreciated.
Everything worked fine with no complaints until yesterday afternoon.

 

Turn just the fan (blower) on to help melt the ice quicker. Put everything back together and try it again after all the ice has melted. If you didn't have all the covers in place, you probably disrupted the normal airflow through the evaporator coil allowing it to ice up.

 

Thanks. I left everything off for a bit, saw the ice was melting, then took a hairdryer to it to help it along. Didn't actually clear it all, but got quite a bit gone, then put a couple of screws in the two panels and turned it back on. So far, so good. Thanks. Didn't think it was going to be a problem. If everything holds, I'll put the half-dozen other screws in.

Thanks

 

Like Bob mentioned.... running just the fan will melt the ice quickly. Make sure your drain problem is resolved because when you get a lot of water quick.....