How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask gotoman for ac Your Own Question
gotoman for ac
gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5206
Experience:  51 years of experience install design and repair of all makes and models of AC
Type Your HVAC Question Here...
gotoman for ac is online now
A new question is answered every 9 seconds

My trane comfortlink II system has an error message err 79

Customer Question

My trane comfortlink II system has an error message "err 79" flashing and a red light on. What is the problem? What do I do?
Submitted: 6 years ago.
Category: HVAC
Expert:  gotoman for ac replied 6 years ago.
79 fault code is 19 seer open low pressure switch. 16 to 20 seer low pressure opened 3rd time hard lockout. Cooling suction pressure below 50 psi. 16 to 20seer Low pressure cutout fault. Heating Mode suction pressure below 25 and OD temp is below 10 degrees. Possible causes are System low on charge. Cooling(indooor air flow restriction) Heating (outdoor restriction) If power is interupted to outdoor unit an error 79 may be displayed on thermostat because it may not have recognized low pressure switch. Turn off power to inside and outside unit and rery system. Code may clear and the unit will operate fine. Russ
gotoman for ac and other HVAC Specialists are ready to help you
Customer: replied 6 years ago.
My HVAC person came out to work on the system and wanted to know where to get a manual.
Expert:  gotoman for ac replied 6 years ago.
I am a Trane service manager so my manual came from Trane. If he Googles Trane Comfort link Manual. There are several sites that he can down load a manual,installer setup and codes. Russ