I replaced Carrier/Bryant board and the led is flashing rapidly.. what can be wrong? It looked like there's problem with polarity,but everything is fine, the led is still flashing.. uff..
Led Code: Continuous on rapid flashing-Line voltage 115 polarity reversed.If twinned,refer to twinnig kit instructions..
The polarity is OK.. checked,transformer is OK.. checked..
It's a carrier furnace 110 BTU looks like 5-10 years old.. I've replaced a lot of boards,(part of my job).. I called some carrier dealers and they didn't know either,they said to change the board again,but the problem remains..
Right now I am really frustreted.. I need yor help guys.. could it be the limit switch?. it's carrier furnace..

Have you tried to reverse the polarity?

Have you tried to reverse the polarity?
No I haven't,I was afraid that I can damage the board..

Ok so the Black wire got to go to the neutral and white to L1?

Yes if that's what it takes to reverse polarity. Normally you would have a pig tail (cord) on the furnace, you would reverse the connections here, if it is hard wired, then reverse where the wires connect to the furnace, you cannot hurt the board by reversing the wiring polarity. Some where in the receptacle or else where it is probably connected wrong.

Yes if thats what it takes to reverse polarity. Normally you would have a pig tail (cord) on the furnace, you would reverse the connections here, if it is hard wired, then reverse where the wires connect to the furnace, you cannot hurt the board by reversing the wiring polarity. Some where in the receptacle or else where it is probably connected wrong.
I'll let you know if it worked ,and thank you very much for your response..

I found the following at:

http://www.scacdtechsupport.com/hot_surface_ignition.html#Reversed_Polarity

"If the unit works fine in cooling, but doesn’t work in heating; check for reversed 115-volt polarity. Reversed polarity can be fixed by shutting off all 115-volt power prior to the furnace at the breaker panel. Unplug the furnace, and then reverse the 115-volt power leads at the furnaces 115-volt junction box. Remember to turn the power back on at the breaker panel when finished."

I have the same problem you have with the red light blinking on and off. I was installing a new digital programmable thermostat, and according to the Lux rep, I have the correct wiring on the thermostat, but the red light at the furnace keeps blinking. If the furnace had a normal electrical plug, I could have easily reversed the plug, but there is no plug. As I researched this further, it is located on the electrical junction box which is inside the furnace wiring area. As I'm not an electrician, I decided to call a regular furnace repair shop to come out and do it for me.

As a follow-up to my previous post. The repairman I hired knew exactly what to look for when he peeked into the front of the furnace wiring. Of all things, the blinking red light is a code which corresponds to several numbers listed on the bottom front of my furnace. Wait for the slow blinking lights and count them... this could be 2 or 3 followed by a series of fast blinking lights.. you count these.. In my case, the repairman counted 2 slow and 4 fast which corresponded to the number 24 which indicated a blown fuse. He pulled it out and replaced it with a new one.. and voilà! Everything worked. I only wished I had the manual for this unit, but the repairman told me the unit was from 1991. Ultimately, it was not a reverse polarity problem, but it could have been. Hope this might help a few of you.

I think all of the carrier furnaces have the code and numbers on a stick on sheet on the front of the blower panel door.

Ok, here it goes: My furnace (Day and Night), by Carrier, progressively got worse and went from heat, to partial heat, to no heat at all with the blower unit staying on and not shutting off. Prior to this, I had replaced the gas valve, pilot light and diaphragm, so they are all new. I changed the board, 3 days ago, wired it exactly like the original I took out and the furnace did the same thing, the fan just kept blowing, with the thermostat off. Now when I turned the thermostat on, the new board flashed and popped and the fuse in it blew. Oh, one more thing, the new board was flashing a constant steady red flash prior to turning on the thermostat.

HELP PLEASE IF YOU CAN, IT'S FREEZING.