Hvac anyone?
 

I've got a Coleman furnace that has decided that it will only blow cold air. The house is at 68 degrees.

Any ideas? Is there a pilot like on a water heater that I can check for? It is gas.

I sure hope so.

how old is it

5 years tops...

Coleman Model # FC30A3XN1A

Not finding anything on the net right off the bat.

When is the last time you had it serviced?

Got any kids in the area who are big enough to throw a valve?

68 is perfect, thats around what my house it set at.

Sure you're not empty? http://lh4.googleusercontent.com/pub...MlQ4HDo0ppjP6s

Nope... mostly older neighborhood.

Honestly, never have had it serviced. Wasn't aware that it needed a yearly checkup.

Check the breaker that it is on first. Don't be afraid to turn it off and back on just to make sure.

Depends it could have a standing pilot, it could have a hot surface ignitor, or a spark ignitor.
How old is the unit? Is it an 80% or a 90% gas furnace? If you don't know how to tell one will have a metal exhaust the other will have PVC for the exhaust.

I like to walk around naked though. My dangle is looking a bit weak. Need that extra 3 degrees for optimum hang.

LMAO

If I go to the thermostat, I can turn the fan on and it blows so I'm guessing that whatever electrical unit in there moves the air is working, IE it has electricity. Am I off there?

The unit is about 5 years old or so. The exhaust looks metal (if on top) though I see some PVC heading to the crawl space towards the bottom.

That number references the A/C coil.
There will be another I.D. plate. It might be outside of the cabinet on the side or inside the door on one side or the other.

Yeah if the blower runs when you turn it on it has power. If it has the metal exhaust then it will be an 80%. The PVC at the bottum is the drain for the A/C coil.

Ok... don't have a model number but I have more information. Looked at the inside of the door there and there is a fault code.

I see a red light flashing 4 times which indicates "limit switch open"

what does that mean? lol

It's kind of tough to tell you from 500 miles away but I'm guessing it's one of several possible things.

Take your doors off the front, there will be a switch that you need to tape down for it to run. Turn off your thermostat for 10 seconds or so and then turn it back on. go to your furnace and let me know what happens. do you see a glow after about 20 secs and does it try to light. Is the combustion motor running, it's the little motor behind the cover you will be looking at the end of it.

It's probably one of these things:
Bad transformer 110v - 24v
Combustion motor not running
thermostat bad ( batteries, not prog correctly likely)
bad igniter or flame sensor

Man this could be a lot of different things. If you have never had it serviced the burners could need to be cleaned which can cause the flame to roll out of the heat exchanger and hit a safety switch.

When you make the thermostat call for heat after it has been off does the inducing motor run?

Does it have an electronics control board with a light on it? If there is and it is blinking count the flashes. The pauses might seperate 2 numbers. There should be a label on the door that will tell you what the flashes mean.

hehe just so your code for the limit switch.
Change your filters...
there is a sensor that goes into the airbox probably on the right side should have 2 wires going into it. there may be a little reset button to hit to reset it. your furnace can't breathe correctly. It is not getting enough airflow or it is over heating. You may also have a small rubber hose going to an airpot pull off the hose and us a little bit of wire like a paperclip and clear the rust that is blocking it inside the limit switch.
Should be one of those.

A Limit Switch is a safety mechanism. You should have a professional come look at it in person.
Limit switch tells me that you have had the flame roll out of the heat exchanger or the heat exchanger is getting to hot.

I think your furnace is being choked for air. You may need to build a little air ramp so air can get into your furnace. Do you have any kind of experience building ramps?

Wierd.

Ok, so I opened up the furnace and it has a button on the front. I push and hold the button and everything fired no problem. I can see the blower turn and I can see 4 gas jets kick on and turn to flame. Seems like the furnace itself is ok...

I replaced the batteries on the thermostat but now I can't get the fan to kick over from the thermostat.

Yeah if it is a high limit you could have a restriction and you should change your filters every month on average.

I need you to ban yourself from this thread now. LMAO

There are 2 limit switches on a furnace. 90 plus percent of the time it is dirty filters not allowing enough air flow or rust inside the switch from condensation. On a 5 year old furnace I would be shocked to have a problem with the heat exchanger. take a pic of the front without the covers on.

I know you will but be sure to watch it and if it does it again do not reset it because that indicate you have a problem. Then call a technician.

taking the cover off cut power to the board and reset it. Is your cover on now? don't forget to check the filters it will probably happen again unless you figure out what was reducing the airflow problem.

Tell you what... I guess these things are like computers. Opened the lid, pressed the last error code button and nothing showed up. Changed the filter and put the lid back on and now everything if firing on all cylinders.

Odd but I'll take it. IF it goes down again I'll be sure to call an hvac tho. The assist is much appreciated for this (less than)HandyMan.

Ask Bugeater he knows his shit.

Another thing that could effect it is if you have shut down the vents in multiple rooms.
Good luck.

bad filter...it worked with the panel off because it was pulling air direct from the room

I need some help.

Freon went out last week on the HVAC unit upstairs. Got it fixed, found out the next morning the thermostat was on the fritz (it was like 64 degrees up there, A/C still running, thinking it was 88). So we replaced the thermostat.

All seemed good, but it hadn't yet needed to run as it's been nice outside lately.

Cue today. I walk upstairs and it's hot as balls, thermostat says 111. I immediately turn the whole thing off, and inside of 20 minutes, it's dropped 4 degrees.

I think when it told the A/C to kick on and cool, it actually told the heater to heat. And since it never got below the 76 degrees it was programmed for, it kept running.

The wiring looks correct. I've looked at the instructions, looks correct. I validated the wiring from the pic of the previous thermostat, looks correct. I looked at the downstairs thermostat (same model), looks correct.

PLEASE HELP ME.

Downstairs, working correctly.

http://images.tapatalk-cdn.com/15/05...64c70d0f26.jpg




Upstairs, hotter than hell.

http://images.tapatalk-cdn.com/15/05...279e3025eb.jpg

Well white is your heat and yellow is your cool and that's correct. I wonder if it's something with the DIP switch. I bet your heat pump may be in heating mode instead of cooling mode.

Brand of system and thermostat?

You really can't go by color, honestly. It depends on how it was wired at the circuit board on the unit.

I think I got it figured out. When my wife installed, she didn't do anything but wire it. There were quite a few system configurations that weren't correct, including the type of system (we have a heat pump).

It's blowing cold air now.

Yeah, you can, the colors are universal.

:facepalm:

Turn in your man car .........NOW!

Hvac anyone?
 

It's a Volvo, I'm not sure it qualifies as a MAN car.

I was not available, and she actually likes doing stuff like that. I am able, but less motivated.

And if I had to turn in a man card every time we had gender roles reversed, I'd be in man card debt. I have health issues that prevent me from doing a lot of the traditional manly roles.

I guess you get a pass for that then. :evil:

Negative ghost rider. Installers will wire things how they choose. Yes there are certain colors that should and are normally standard, but some use either brown, black or blue for the common. If you have a Ruud or Rheem their reversing valve is energized the opposite of everyone else. If you have a multiple stage equipment with multiple Y terminals or if you have 3 sources of heat. It is always best to see how the outdoor and indoor units were wired to insure you get it all back together correctly.

White=heat
Yellow=cool
Red=24v power
Green=blower
Orange=Reversing valve

I know what the **** I'm talking about here, I work on this shit all the time.

You obviously dont. Color means nothing.

Ok, the common may vary. JD1020 can now start answering all HVAC questions since he ****ing obviously knows it all.

If you can't understand the common sense about how a 5 wire can be wired up differently depending on the technician that installed the equipment then I don't know what to say.

Would you like to know how I know this? Because I was taught which colors were for what and then when I was on my first job site, my boss asked me why I used those colors. I told him because thats how I was taught. He then told me that he usually does blah blah blah. Guess what? It still worked exactly how it was suppose to. You know why? Because colors dont mean shit.

I think he understands just fine. You are trying to paint an extreme picture. Any installer that uses different colors for power, fan, heat, and cooling should have his ass chewed out and made to fix it. Then probably fired for being a rogue asshole.

When I was still working as a tech I saw all kinds of colors used for different things, I think the only one that I saw didn't change was green for the fan. All I cared about was if they matched up on the circuit board. And all I said was that you can't go by the colors at the t-stat and then I was told, "yes you can." Which is 100% false.

you are assuming that some ****ing drooling mongoloid didn't hook the wires up in the wrong spots on the other end

They could all be one color and work if they were wired up correctly.

Data cabling has a standard too, but if is not followed, it can still work as long as all wires are landed the same on both ends.

Same goes for phone and electrical.