Amana Air Command 80 Gas Fired Furnace (4 blinks) troubleshooting

Can you help me troubleshoot my Amana Air Command 80 gas-fired furnace?

  1. Today it stopped heating the house; three red blinks were visible. The instructions say this means the "pressure switch is stuck open".

  1. I could see the "top" (smaller" motor wasn't spinning) but the bottom (bigger) motor was spinning; so, I guessed, there was no vaccum to the pressure switch - hence - the pressure switch was stuck in the open (off) position.

  2. To test, I removed the hose from the top (smaller) motor & sucked on it.

  1. This self-induced vacuum caused the diaphram to move which caused the mechanical switch connected to the pressure valve to close (I could see the switch move when I sucked on it).

  2. The flame ignighter heated up and the gas started burning. The three blinking red LED signal went out; I thought I "fixed" my furnace.

I cycled the power a few times while I cleaned the filters and blew dust from around the wires.

But ...

  1. Then the Amana Air Command 80 gas-fired furnace stopped heating again; this time, four red blinks were visible!

  1. Now the opposite ocurred; the "top" (smaller) motor was now spinning but the bottom (big) motor was not spinning. No air was circulating through the house.

  2. Four blinks indicate an "open Limit Control (primary or auxilliary)".

  1. If I cycle the power to the furnace, it works for about ten minutes and then the bottom (big) motor stops spinning and the four blinks start again.

I have a few questions: a) How can I troubleshoot this Amana Air Command 80 gas-fired furnace? b) Is there a reset switch somewhere? c) Is there a maintenance guide on the web somewhere?

Thanks, Donna

Reply to
Donna Ohl, Grady Volunteer Coo
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Despite the fact that three bl Open Limit Control (Primary or Auxiliary) If either limit control opens, the air circulation and vent blower will be turned on until the limit closes. The diagnostic light code for this is four short flashes followed by a pause. The probable cause is either: a) Low conditioned air flow due to dirty filter or resistance in duct work, b) Faulty limit, faulty blower, or blower speed set too low.

What does that mean? What is a "limit control"? Which motor is the "air circulation" (bottom big motor?) blower? Which motor is the "vent blower" (top small motor?)?

I know the filter is clean because, while it was really dirty, I replaced it and I still have the problem. I have no idea how to test resistance in the duct work, but, I didn't change anything to change that, either before or after the problem ocurred.

I would have no idea how to set the blower speed.

What's a faulty "limit" and how would I test to ascertain the cause?

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

You will need to call someone out to fix your furnace, but here are some answers to your questions.

The "limit" is a thermostatic switch inside of the furnace that is there to shut down the burners if it gets too hot. It sounds like it's doing it's job. The problem you now have sounds like a bad blower motor (The large motor that circulates air through you house). Try seting the fan switch on your thermostat to "on" if you can. That usually will operate the fan on high speed and it may get you by for a while if it works. If you have air conditioning and you have been neglecting you air filters, you also may have a plugged up evaporator coil. The furnace guy will likely need to take apart or cut a hole in the ductwork surrounding the evaporator coil to inspect and clean it if needed.

The problems you were having earlier with the pressure switch could be caused by something getting stuck in the flue. Sometimes, small birds or other animals like to hang out on the flue pipe on the roof since it is warm. They then pass out from the carbon monoxide and fall into the pipe causing a "restriction". Someone will need to disconnect the flue pipe from the top of the furnace and look inside of it and remove the dead creature if there is one.

Like I said earlier, time to get the checkbook or creadit card ready and call a reputible heating company to come out to fix your furnace. Good luck.

Reply to
bfrabel

If I were you, I would call a professional repair person to deal with this problem. You are asking about a piece of equipment that could cause serious damage to your home and death and injury to you and your family if you mess with it and screw something up. Call a professional heating and repair person to fix the problem.

Reply to
Shawn Hirn

Do you think the non spinning smaller top motor may be the problem? D'uh? You really desperately need a furnace repair tech.

Reply to
Stormin Mormon

The smaller motor needs to spin, to do several things. Including blow the carbon monoxide out the chimney. Call a repair company.

Reply to
Stormin Mormon

I do have air conditioning as part of this furnace setup. I never did any maintenance on it (it's about seven or so years old).

I'd be glad to clean this AC coil; where would I find it? Also, do you know of a good source on the web for furnace & ac maintenance WITH PICTURES?

Reply to
Donna Ohl, Grady Volunteer Coo

I did. He'll be out here on Saturday. Isn't there ANY maintenance a homeowner can do themselves?

I'm sure, from the symptoms, that the "limits" kicked in, probably due to some problem with air circulation.

Besides the filter (which was very dirty but I replaced it yesterday), what other maintenance can I do.

For example, someone said clean the A/C coils ... but WHERE ARE THEY?

The furnace is in a tiny closet. The AC fan is outside the house.

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

Leave it alone. Let the pro fix it. You can ask him about what you can do with the maintenances. Just keep your pipes from freezing until he gets there.

--Vic

Reply to
Vic Smith

From what you've described, your inducer fan needs to be replaced. Gonna be a job for the service tech.

Buy a portable heater?

Reply to
Stormin Mormon

Stormy, Buy a brain. Yours isnt worth a shit. Bubba

Reply to
Bubba

Only in the beginning. Now both fans run continuously but the flame goes out, likely because of a limit being reached.

Tomorrow the repairman arrives.

I'm amazed, on the entire net, I can't find a single photographic description of how to maintain an Amana Air Command 80 gas-fired home closet furnace.

This is shocking for home repairees.

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

Hey, my Rheem Criterion II is short-cycling, and the troubleshooting manual is packed away in a box somewhere. I think it's a limit switch, maybe the flame sensor tossing an error when it heats up too much, the thermostat, or just rapid heat loss from the house because it's been near 0F here. Not a big deal, but the short cycling irritates me. I've fixed this thing before (ignitor) and the manual was useful. Couldn't find anything on the net, unless I had a HVAC license or whatever. I think the repair industry has the manuals locked down. Kind of makes sense from the safety aspect that they typical homeowner could get him and his family killed messing with the furnace. Of course we're not typical, are we? Anyway, you can find a dealer to get your manuals, but the net is a poor resource for them.

--Vic

Reply to
Vic Smith

Maybe the folks who build them would prefer that only the trained techs work on them?

Reply to
Stormin Mormon

Well, the guy called yesterday and said a client cancelled and ended up coming over 1 day early.

He fiddled with a paper clip in the combustion motor orifice but that didn't solve anything. He looked about, here and there, and decided something was wrong but he knew not what. He cleaned the flame sensor but that didn't change anything.

He said basically what everyone here said. There is something wrong with the flow of air because the furnace is shutting itself off. He said we'd have to pay 400 for his son to come back and clean out the "condenser coils". I was aghast that he was guessing what the problem was and that his son was doing the work but he said he was qualified. So, I paid the $100 visit fee and 25% of the cleaning fee as what could I do (you all said we have to bring over the tech folks).

My new question ... Is this a normal thing where the problem isn't obvious so you start cleaning? It seems so based on the prior responses here but I'd like to doublecheck, especially since four days takehome pay (for me) are riding on this.

Thanks for your advice, Donna

Reply to
Donna Ohl, Grady Volunteer Coo

I did, I did! I called Amana many times - they are the ones who referred me to the repairman who showed up at my house. What else would you recommend other than an Amana-recommended repairman. I don't get it.

Here's what I did ..

First I called the Amana number in the maintenance manual (pretty crappy manual, I might add) at 800-843-0304. They were closed so a day later I called again but they referred me to 888-842-2440, which turned out not to handle furnaces (the Amana personnel didn't know the difference between a furnace and an air conditioner).

Finally, they referred me to 877-337-3636 which did handle Amana forced-air furnaces.

That third number provided me, based on my zip code, three possible repairpeople. I called the first one they gave me and he's the one who came by.

Are you saying we should not go to the ones Amana recommends?

Reply to
Donna Ohl, Grady Volunteer Coo

You are not understanding what Im saying. You are correct. Do NOT call the ones Amana recommends. Re-read what you just typed and tell me why you would use them. They have no idea about the company they are recommending. They are giving you a name based on a zip code and nothing else. Again..........do this: In your area there are Heating/Cooling wholesalers. These are companies that stock furnaces/air conditioners, sheetmetal and repair parts. Unfortunately for you, they only sell to dealers (guys like me) that make a living installing and repairing heating and cooling equipment. Call that place (the wholesaler). Tell them (the guys at the counter that see guys like me every day) you have an Amana furnace. You are having a problem with it and you would like to know the best company out there that would fix his furnace if he were having a problem. Those guys at the counter know who the hacks are and who the good guys are. Then call that company and ask what they charge to come out or if they charge flat rate or hourly. Then make your decision. Bubba

Reply to
Bubba

I called another company, as you advised, and they came out this morning. They said they'd charge $80 to come out and that would be put toward parts. They too were not sure what the problem was, but here is verbatim what they wrote on the sales slip afterward.

Can you help decode this for me? The furnace is work Found PSC Motor Running slow and High Limit kicking out & re-setting either bad motor or dirty coil. More than likely coil. Motor is not hot to touch. $80

Reply to
Donna Ohl, Grady Volunteer Coo

The PSC motor is running slower than it should be and the limit is tripping.

Thats what he thinks is the most likely cause of the above.

That should be obvious.

So its unlikely to be a bad motor.

Reply to
Rod Speed

PSC is Permanent Split Capacitor motor. Again, I hate to say but you got someone that doesnt want to spend the time to give you a proper diagnosis. A motor is easily diagnosed. A dirty coil is too but just takes a few minutes more with an inspection camera to be stuck inside the furnace where the limit control is. Aim it up at the bottom of the evaporator coil and wahh-laah. You have a picture of the bottom of the coil.........clean or dirty. Id tell them to come back out and give you a proper/definite diagnosis. If its a dirty coil you'll have to have it cleaned and then get a filter system that keeps the dirt off of it. Bubba

Reply to
Bubba

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