Durham Region Air Conditioning Repair, Service and Installation
The flashing LEDs on your A/C will correspond to a specific fault code that is shown here.
Comfort Alert Diagnosis Chart Single Phase Unit.
CODE: Green "POWER".
RESULT: Module has power.
FIX: Supply voltage is present at module terminals.
RESULT: Module has power.
FIX: Supply voltage is present at module terminals.
CODE: Red "TRIP".
RESULT: Thermostat demand signal Y1 is present, but the compressor is not running.
FIX: Compressor internal overload is open. Broken wire or connector is not making contact. Low pressure switch open, if present. Compressor contactor has failed open.
RESULT: Thermostat demand signal Y1 is present, but the compressor is not running.
FIX: Compressor internal overload is open. Broken wire or connector is not making contact. Low pressure switch open, if present. Compressor contactor has failed open.
CODE: Yellow "ALERT" Flash Code 1.
RESULT: Long Run Time Compressor is running extremely long run cycles.
FIX: Low refrigerant charge. Evaporator blower is not running. Evaporator coil is frozen. Faulty TXV. Condenser coil is dirty. Liquid line restriction (filter drier blocked if present in system). Thermostat is malfunctioning.
RESULT: Long Run Time Compressor is running extremely long run cycles.
FIX: Low refrigerant charge. Evaporator blower is not running. Evaporator coil is frozen. Faulty TXV. Condenser coil is dirty. Liquid line restriction (filter drier blocked if present in system). Thermostat is malfunctioning.
CODE: Yellow "ALERT" Flash Code 2.
RESULT: System Pressure Trip Discharge or suction pressure out of limits or compressor overloaded.
FIX: Condenser coil poor air circulation (dirty, blocked, damaged). Condenser fan is not running. Return air duct has substantial leakage. If low pressure switch is present, check flash code (1) information.
RESULT: System Pressure Trip Discharge or suction pressure out of limits or compressor overloaded.
FIX: Condenser coil poor air circulation (dirty, blocked, damaged). Condenser fan is not running. Return air duct has substantial leakage. If low pressure switch is present, check flash code (1) information.
CODE: Yellow "ALERT" Flash Code 3.
RESULT: Short Cycling Compressor is running only briefly.
FIX: High head pressure. Thermostat demand signal is intermittent. Time delay relay defective, if present. Hot gas sensor defective, if present.
RESULT: Short Cycling Compressor is running only briefly.
FIX: High head pressure. Thermostat demand signal is intermittent. Time delay relay defective, if present. Hot gas sensor defective, if present.
CODE: Yellow "ALERT" Flash Code 4.
RESULT: Locked Rotor.
FIX: Run capacitor has failed. Low line voltage (contact utility if voltage at disconnect is low). Excessive liquid refrigerant in compressor. Compressor bearings are seized.
RESULT: Locked Rotor.
FIX: Run capacitor has failed. Low line voltage (contact utility if voltage at disconnect is low). Excessive liquid refrigerant in compressor. Compressor bearings are seized.
CODE: Yellow "ALERT" Flash Code 5.
RESULT: Open Circuit.
FIX: Compressor contactor has failed open. High pressure switch is open, If present. Open circuit in compressor supply wiring or connections. Unusually long compressor protector reset time due to extreme ambient temperature. Compressor windings are damaged.
RESULT: Open Circuit.
FIX: Compressor contactor has failed open. High pressure switch is open, If present. Open circuit in compressor supply wiring or connections. Unusually long compressor protector reset time due to extreme ambient temperature. Compressor windings are damaged.
CODE: Yellow "ALERT" Flash Code 6.
RESULT: Open Start Circuit Current only in run circuit.
FIX: Run capacitor has failed. Open circuit in compressor start wiring or connections. Compressor start winding is damaged.
RESULT: Open Start Circuit Current only in run circuit.
FIX: Run capacitor has failed. Open circuit in compressor start wiring or connections. Compressor start winding is damaged.
CODE: Yellow "ALERT" Flash Code 7.
RESULT: Open Run Circuit Current only in start circuit.
FIX: Open circuit in compressor run wiring or connections. Compressor run winding is damaged.
RESULT: Open Run Circuit Current only in start circuit.
FIX: Open circuit in compressor run wiring or connections. Compressor run winding is damaged.
CODE: Yellow "ALERT" Flash Code 8.
RESULT: Welded Contactor Compressor always runs.
FIX: Compressor contactor has failed closed. Thermostat demand signal not connected to module.
RESULT: Welded Contactor Compressor always runs.
FIX: Compressor contactor has failed closed. Thermostat demand signal not connected to module.
CODE: Yellow "ALERT" Flash Code 9.
RESULT: Low Voltage Control circuit < 17VAC.
FIX: Control circuit transformer is overloaded. Low line voltage (contact utility if voltage at disconnect is low).
RESULT: Low Voltage Control circuit < 17VAC.
FIX: Control circuit transformer is overloaded. Low line voltage (contact utility if voltage at disconnect is low).
See What Our Customers Are Saying:
Apr 28, 2022
I left a live chat message on their website that my air conditioning was not working. Within 1hr a representative called me to discuss my options.
The next day he came to the house to review my needs and give me a price for a new system. Price quoted was less than I expected and the installation was completed the following day. I found their salesman and the installers very knowledgeable and easy to deal with. All my questions were answered. Everything was properly explained in regards to what unit was needed and why, along with instruction where needed for use.
The installers made sure everything was working properly before they left.
Apr 28, 2022
This is to thank Twintech Heating and Cooling for their exceptional and timely service. Mitch, their technician was very courteous and generous with his time right from his first meeting with us. He not only took the time to check everything but also educated us on why we needed what he recommended. Greg and Mitch graciously accommodated us on our requested day and time for job to be done. They were both very courteous and responsive to our needs and special requests especially in a tight spot. The job was finished neatly and on time. Thank you Twintech for your great service !
Apr 28, 2022
They came the day and time they had planned for us and were very fast and efficient! The AC works amazing and it is amazing during the heat of the summer we have already got! Thanks for everything you did for us!
Apr 28, 2022
Would recommend this company to friends and family in a heartbeat. Very professional , on time and left no mess when the job was done.
Apr 28, 2022
Great customer service. Responsive and professional. I would highly recommend Twintech, I used them previously for repair service and a new air conditioner- very satisfied.
Apr 5, 2022
Our air conditioner failed. Made a call and within 15 min a technician was at our door.
The issue was fixed and many suggestions were provided.
Thanks to Mitch. Great service !
Apr 5, 2022
Our furnace was rattling, as soon as we put our air conditioner on this past week. We had researched looking for a company that was Registered with Better Business Bureau, and this company TwinTech, had A+ Rating. Scott, was immediately helpful via text/phone and sent his technician as soon as he was able...Mitchell/technician provided great professional service. Thank you TwinTech.
Sean and Debbie
Apr 5, 2022
I contacted various companies when looking to install a new furnace and I found Twintech to be transparent with their communication and approach. They had options to suit my various requirements and the price vs quality was very good. The after installation communication was also very good and they answered all queries I had.
Apr 5, 2022
My furnace broke down last month. The team was quick to respond, courteous, professional and mindful of COVID-19 concerns. I highly recommend them if you are considering replacing or servicing your HVAC equipment.
Apr 5, 2022
I was very happy with the installation and price. I would definitely recommend. Thank you Twintech.
See What Our Customers Are Saying:
Aug 8, 2025
We are very happy to recommend this company to everyone. Our furnace broke down on Sunday morning. We phoned them and before noon Grant the owner showed up. He worked on the furnace for about a hour not wanting to give up to fix the problem. The furnace was 17 years old. I was the one talking about replacing it. End result was the next day it was all done. On the Sunday Bob came over with heaters to warm up the house. We decided to replace the water heater at the same time. Thanks Grant for the excellent work. Thumbs up.
Aug 8, 2025
Right on time. Explained how to work the HRV in a different way so the house would not be so dry. Changed my whole house water filter for me as well. Friendly, helpful, caring service!
Feb 18, 2025
Very pleased with the professional service that TwinTech Heating and Cooling provided in replacing my furnace. I got several quotes from different service providers. Their price was excellent and they explained the features very well. We are very glad we went with TwinTech and highly recommend their services.
Feb 18, 2025
We were new homeowners in need of a second opinion. TwinTech Heating & Cooling were Amazing and professional. Very knowledgeable and great service all around. Recommend to anyone looking for honest and reliable services. Treated with respect and care. Thank you Greg, Mitch and Bob!
Feb 18, 2025
TwinTech is an excellent and honest company! I called them for a second opinion after being told by another company that I needed to replace my furnace. Turns out this was not the case at all! I did not need a new furnace. TwinTech did not push to make an unnecessary sale and saved me from a huge expense. Bob and Mitch were extremely professional and above all honest! I definitely recommend TwinTech!
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