Have HVAC Questions? Ask an HVAC Expert for Answers
Those are sophisticated systems, tell me please a lot about your technical background and if you have a multi meter to run some tests with or not. I will be able to coach you most effectively that way.
The problem is most often in the 24volt controls circuit. If you can see that digging into the system is not something you feel able to do, tell me which direction you are from the center of the nearest city and I will get you a short list of the best rated companies in your area that can do the diagnosis and repairs.