I have a 5 yr old lennox Merit series heat pump and the ac has stopped cooling the house. The heat works fine. Everything turns on, and there is some air blowing out of the vents but its weak and doesn't cool the house down. The outside lines are not hot or cold to the touch. The red and green led's flash at the same time, about every second. I'm not sure if that is considered fast or slow? Could it need refridgerent? Leaving on vacation next week and not really wanting to spend everything before we leave. I have replaced the air filter which wasn't even a month old and I cleaned the outside of the unit. Any help would be great :)