AMANA GUID090EA50

[hawgwildtours]

This furnace led blinks continuously and the the burner lights but goes right back out. My friend changed the flame sensor but no help. Any ideas beside main board????thanks in advance

Edited December 20, 2011 by hawgwildtours

[RegUS_PatOff]

This furnace led blinks continuously ...

continuously, ?

OR repeats a certain number of flashes ?

[hawgwildtours]

I was wondering the same thing. I will go by his house tonight and see

[hawgwildtours]

I just called him and he says it is continuos

[applianceman18007260692]

Continuous flashing on the LED might mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram

Edited December 20, 2011 by applianceman18007260692

[Bobice]

AMANA & GOODMAN FAULT CODES

1. One led flash that stays on continuously = No signal from thermostat. Turn off power and check connections.

2. One led that flashes = Furnace lockout after three attempts to fire. Must be reset by lowering it for twenty seconds and then raise it back. After one hour furnace will reset itself.

3. Two led flashes = Draft Inducer not working or shorted or failed pressure switch.

4. Three led flashes = Open pressure switch.

5. Four led flashes = open primary limit switch due to faulty wiring or bad filters.

6. Five led flashes = Sensing flame without a call for heat due to possible slow closing valve.

7. Seven led flashes = faulty flame sensor

8. Eight led flashes = faulty igniter

9. Continuous led flashing = Reverse polarity. Check wiring diagram

[hawgwildtours]

My friend had changed the igniter instead of the sensor. I cleaned the sensor and all is well. As for the blinking light this furnance was wired with 2 thermostats for a two story house and they used two boards. There was a green led on the add on board but it was saying normal operation. Main board did not have power to it until downstairs called for heat. Thanks again for all help

[jb8103]

My friend had changed the igniter instead of the sensor. I cleaned the sensor and all is well. As for the blinking light this furnance was wired with 2 thermostats for a two story house and they used two boards. There was a green led on the add on board but it was saying normal operation. Main board did not have power to it until downstairs called for heat. Thanks again for all help

Two boards for one furnace? Never seen that before.

[Shootist]

When getting a flame sensor error always make sure the furnace is properly grounded before you do anything else. An ungrounded furnace will pull a little ground off of the gas line but this is not a good ground source and the furnace will work when it feels like it and drive you up a wall. If the ground is good then cleaning the sensor rod with a little steel wool or fine grit sandpaper will usually fix it.

I had a customer once that had a heater problem. Every fall their previous A/C guy had to come out and replace the flame sensor. This went on for years and finally they got fed up and called me instead. I knew right away the problem once I saw the old 2-prong socket in the attic. Luckily the water heater was close by so I ran a new ground wire to a ground clamp on the cold water line and the furnace fired right up. The following fall I got a "thank you" card from this customer because it was the first time in years the furnace worked right the first cold spell.

[michla]

I know this might be a little late coming, but I had the same problem with your model last Spring. A closer look revealed a pressure switch (round diagpham cannister looking thing with small hose attached to it) that was tripping off prematurely. The Draft Induced Blower (first thing to start in the forced air heating cycle, purges exhaust gases to exterior) has a purpose-built hose nipple to send positive air pressure down that small hose via the spinning fan in the DIB....be it ever so small CFM of air movement.

Problem is, if anything is compromised in that small air signal to the pressure switch, the diaphram plunger pintle will not extend far enough to comletely and consistently trip (close the contacts) in the lever microswitch (mounted on one side of the pressure swith pot) to send the signal the controller (LED box) wants to see. Any interruption/failure in the pressure switch tells the Controller the Draft Induced Blower is not running (even if it is) --which is an UNSAFE condition and the entire heating cycle process comes to an abrupt halt.

So, what you've got is a weak air signal to the pressure switch, which can be caused by:

--ruptured/torn rubber hose from DIB to Pressure Switch

--tired DIB spinning at lower rpm's creating less air movement than needed

--an "air leak" somewhere in the intake/exhaust manifolds for the DIB

--a faulty and/or leaking pressure switch

I finally found a new DIB on Ebay (they're very expensive) for my Amana just like yours, but that still didn't cure the problems like you're experiencing. It wasn't until I played with bending the microswitch metal mounting tab on the pressure switch that I could affect a changed relationship of the air signal/pintle engagement at the microswitch that made the big difference. It was very tricky positioning that arc of bend in the tab just right, but after much patience and testing, I finally got it right. You have to be very careful though by bending the tab only micro-inches at a time in your trial-and-error process---too much bend and the furnance cycle gets befuddled by the sequence of the switch contact cycle.

Just don't let any appliance parts salesmen talk you into buying one of those "Adjustable Pressure Switches" if you decide to replace yours instead (it may still need tweaking anyway). The adjustables are not only junk, they never operate consistently and will confuse your furnace even more! I know...I tried one.

[_Carl_]

On 12/20/2011 at 2:33 PM, applianceman18007260692 said:

Continuous flashing on the LED might mean your furnace has a reversed polarity of 115 volts. Turn off the power and correct the wiring polarity after reviewing the wiring diagram

I have an amana gula090ax50 using propane, doing the same thing..flashing the red led continuously.The furnace tries to light, the burners come on then go out, this will happen 4 - 5 times then it stops completely..at this point is when I seen the continuous flashing led on the main board. How does the polarity get reversed in the first place ?

 

Here is a chronological order of event since problems started:

1 About a year ago the burners would try to light then go out and blower would just run continuously with no heat. ( repair man tapped the pressure switches with a screw driver) it worked after this. He said they get stuck sometimes and I eventually would have to replace them. 

2. Recently ( two weeks ago) the furnace started to go out as soon as the burners come on but would always work after the second try.

3. I tested the pressure switches and they both had 24v to them. I tested the primary automatic limit switch and it had no continuity. I replaced the limit switch and it started working normally again for the last two weeks until this morning at 3am and -18 f outside  

4. When I replaced the limit switch the blue wire was on top and the other wire was on bottom, but when I got the new switch it was shaped a bit different..I couldn't see any marking on either switch to represent a + or - side. A tech on YouTube told me the wire orientation on the switch didn't matter but now I'm wondering if maybe this is the cause of my reverse polarity ? 

5. I turned off power to the furnace and switched the wire position on the limit switch to see if that would change anything and the furnace light up and stay on working normally...so far.

6. When I had the multimeter on one pressure switch I did see a large voltage drop but I may have moved the lead off slightly as its hard to keep it in place due to the terminal being up inside the switch slightly. I was going to unscrew the pressure switch from the furnace to get a better angle to test it but didn't because I'm not sure if being screwed to the furnace is acting as its ground ( I guess I could just rest it on the metal housing on the furnace ? ) should the pressure switches be getting 24v all the time or just during a certain sequence ?

7. I am going to try taking off the hoses to the pressure switches and blow though them to see if any blockages ( not blowing into the pressure switch , I know this will ruin them) and also check the orifices they are attached to for any crud there blocking air flow.

Anyone have any ideas ?

 

 

 

 

[_Carl_]

Switching the wires didn't seem to work although after trying about 5 times it did come on and is currently blowing heat.

 

during the summer my propane company replaced a part on my propane tank ( the main valve with the vent on it)..is it possible they didn't set the pressure high enough..would low gas pressure cause issues like this ?

[_Carl_]

hoses were clear. 

I noticed this time when the 4 burners light up the far left one was having trouble but finally came on. Indication of low gas pressure ?

[_Carl_]

After further testing I think I've figured out the left pressure switch is bad based on the following data: (someone please double check my method of testing)

multimeter positive lead connected to one of the two terminals on pressure switch  (with furnace wires still connected) , negative lead to a solid ground.

 

Right Pressure Switch:

maintains 26.5 - 26.9 v during initial starting sequence (never fluctuated beyond this)

when burners light up it drops to 24v and stays there...seems normal.

 

Left Pressure Switch:

fluctuating voltage during initial start sequence  0.15 v - 00.0v - 24.6v (burners try to light)- 7.6v - 0.00v - 24.6v (burners try to light) - 00.0v - 24.6v(burners try to light) -00.0v

 

I will refer to the experts here, but I'm think this proves a left pressure switch is at fault ? if so I will replace both since the other is probably not far from failure too.

 

 

 

 

 

[_Carl_]

I forgot to mention something,  I noticed there is now a slight gap between the lower unit of my furnace and the upper part by maybe 3/8 of an inch, I can now see the little lip on the lower unit where the upper unit rests against it. The caulking that sealed the two together is now opened up.  It looks like the floor where the furnace is located has settled on me. 

I wanted to mention this after reading this "Any leaks in the heat exchanger or your combustion chamber could cause a weak negative pressure at the draft inducer housing port."

[_Carl_]

I also just removed each switch from the furnace to test for continuity, neither switch has continuity.

 

 

[AccApp]

Please start your own topic. It’s a lot less work than what you’ve done already.

[_Carl_]

ok done, you can delete my posts here now. 

[applianceman18007260692]

appreciate the update

[_Carl_]

For those who may want to view my furnace issue at its new location it can be seen here https://appliantology.org/topic/65741-amana-gula090ax50-furnace-furnace-starts-then-stops/