I got the following error code on my Carrier WeatherMaker 8000 two-Speed gas Furnace (model number 58TUA 10016) (S/N 0394A12056) which was installed in 1994:
45 = replace control: I got this code after noticing the actual temperature in the house had dropped to 60 degrees – burrrrr! The normal setting is also 68 degrees. I reset the circuit breaker and the toggle switch right on the furnace, and it fired up immediately. The code went back to normal.
Same thing happened two days later and rectified using the exact same approach.
The model number on my control board is HK42FZ005. It is made by united technologies electronic controls in huntington indiana. I called them. They gave me the name of a distributers in my area. I couldn't find a distributer who would sell me the part (liability concerns)
I called a service man and he claimed that the error code was not necessarily indicative of the problem. In other words, he could change the controller out and it still might display the same intermittent behavior. He said the error code does not mean I should replace the board. It only tells me where to start looking for the problem.
Question: Should trust the service guy or should I just purchase the controller on line and R & R it myself?
Intermittent problems are the worst and NOBODY has the answer for you. I would get a experienced Carrier tech to check for other problems. Lots of posters swap a lot of parts out and end up calling a Pro anyway. At 16 yrs old the board may be defective so you can choose to change it and it may get damaged by the real problem. May be a VERY expensive board if it is a 2 stage furnace. http://www.americanhvacparts.com/
"Cut it twice and it is still too short".