We have recently bought a house that did not come with any manuals so I am at a lost. We have a programmable thermostat by carrier and we had just put on the ac part and now it is blinking Trouble. Does anyone know what might be causing it to do that? We already replaced the filters since there was none. I do know that it was serviced about 11 yrs ago. Any help or suggestions will be appreciated. Thank you :)

I do know that it was serviced about 11 yrs ago

If it has been 11 years since the system was serviced now is the time to get it serviced before the heat arrives and you end up with no cooling.
At the same time of the service mention about your thermostat problem.