Durham Region Air Conditioning Repair, Service and Installation
The codes are flashed by a series of short and long flashes of the status light. The short flashes indicate the first digit in the status code, followed by long flashes indicating the second digit of the error code.
CODE: On solid, no flash.
RESULT: None.
FIX: Normal operation.
RESULT: None.
FIX: Normal operation.
CODE: Rapid continuous flashing.
RESULT: Standard Thermostat Control 288ANA/180ANA only.
FIX: Unit being controlled by standard thermostat inputs instead of Evolution Control. Only high stage operation is aveliable. This operating mode should be used in emergency situations only.
RESULT: Standard Thermostat Control 288ANA/180ANA only.
FIX: Unit being controlled by standard thermostat inputs instead of Evolution Control. Only high stage operation is aveliable. This operating mode should be used in emergency situations only.
CODE: 1 pause.
RESULT: None.
FIX: Normal operation.
RESULT: None.
FIX: Normal operation.
CODE: 2 pause.
RESULT: None.
FIX: Normal operation.
RESULT: None.
FIX: Normal operation.
CODE: 16.
RESULT: System Communications Failure.
FIX: Communication with User Interface lost. Check wiring to UI, indoor and outdoor units.
RESULT: System Communications Failure.
FIX: Communication with User Interface lost. Check wiring to UI, indoor and outdoor units.
CODE: 25.
RESULT: Invalid Model Plug.
FIX: Control does not detect a model plug or detects an invalid model plug. Unit will not operate without correct model plug.
RESULT: Invalid Model Plug.
FIX: Control does not detect a model plug or detects an invalid model plug. Unit will not operate without correct model plug.
CODE: 31.
RESULT: High Pressure Switch Open.
FIX: High - pressure switch trip. Check refrigerant charge, outdoor fan operating and coils for airflow restrictions.
RESULT: High Pressure Switch Open.
FIX: High - pressure switch trip. Check refrigerant charge, outdoor fan operating and coils for airflow restrictions.
CODE: 32.
RESULT: Low Pressure Switch Open.
FIX: Low - pressure switch trip. Check refrigerant charge and indoor air flow.
RESULT: Low Pressure Switch Open.
FIX: Low - pressure switch trip. Check refrigerant charge and indoor air flow.
CODE: 45.
RESULT: Control Fault.
FIX: Outdoor unit control board has failed. Control board needs to be replaced.
RESULT: Control Fault.
FIX: Outdoor unit control board has failed. Control board needs to be replaced.
CODE: 46.
RESULT: Brown Out (230v).
FIX: Line voltage < 187v for at least 4 seconds.
RESULT: Brown Out (230v).
FIX: Line voltage < 187v for at least 4 seconds.
CODE: 47.
RESULT: No 230v at Unit Measured at L1 and L2 on circuit board.
FIX: There is no 230v at the contactor when indoor unit is powered and cooling/heating demand exists.
RESULT: No 230v at Unit Measured at L1 and L2 on circuit board.
FIX: There is no 230v at the contactor when indoor unit is powered and cooling/heating demand exists.
CODE: 53.
RESULT: Outdoor Air Temp Sensor Fault.
FIX: Outdoor air sensor not reading or out of range.
RESULT: Outdoor Air Temp Sensor Fault.
FIX: Outdoor air sensor not reading or out of range.
CODE: 55.
RESULT: Outdoor Coil Sensor Fault.
FIX: Coil sensor not reading or out of range. Ohm out sensor and check wiring.
RESULT: Outdoor Coil Sensor Fault.
FIX: Coil sensor not reading or out of range. Ohm out sensor and check wiring.
CODE: 56.
RESULT: Thermistors out of range.
FIX: Improper relationship between coil sensor and outdoor air sensor. Ohm out sensor and check wiring.
RESULT: Thermistors out of range.
FIX: Improper relationship between coil sensor and outdoor air sensor. Ohm out sensor and check wiring.
CODE: 71.
RESULT: Low Stage Thermal Cut out.
FIX: Compressor operation detected then disappears while low stage demand exists. Possible causes are internal compressor overload trip or start relay and capacitor held in circuit too long.
RESULT: Low Stage Thermal Cut out.
FIX: Compressor operation detected then disappears while low stage demand exists. Possible causes are internal compressor overload trip or start relay and capacitor held in circuit too long.
CODE: 72.
RESULT: High Stage Thermal Cut out.
FIX: Compressor operation detected then disappears while low stage demand exists. Possible causes are internal compressor overload trip or start relay and capacitor held in circuit too long.
RESULT: High Stage Thermal Cut out.
FIX: Compressor operation detected then disappears while low stage demand exists. Possible causes are internal compressor overload trip or start relay and capacitor held in circuit too long.
CODE: 73.
RESULT: Contactor Shorted.
FIX: Compressor voltage sensed when no demand for compressor operation exists. Contactor may be stuck closed or there is a wiring error.
RESULT: Contactor Shorted.
FIX: Compressor voltage sensed when no demand for compressor operation exists. Contactor may be stuck closed or there is a wiring error.
CODE: 74.
RESULT: No 230v at Compressor.
FIX: Compressor voltage not sensed when compressor should be starting. Contactor may be stuck open or there is a wiring error.
RESULT: No 230v at Compressor.
FIX: Compressor voltage not sensed when compressor should be starting. Contactor may be stuck open or there is a wiring error.
CODE: 75.
RESULT: Low Stage Did Not Start.
FIX: Specified start voltage at VR terminal was not achieved in low stage. Start relay was de-energized after 1 second.
RESULT: Low Stage Did Not Start.
FIX: Specified start voltage at VR terminal was not achieved in low stage. Start relay was de-energized after 1 second.
CODE: 76.
RESULT: Low Stage Did Not Start 3 times.
FIX: For 3 consecutive low stage starts, the specified start voltage at VR terminal was not achieved and start relay was de-energized. Low stage locked out for 30 minutes.
RESULT: Low Stage Did Not Start 3 times.
FIX: For 3 consecutive low stage starts, the specified start voltage at VR terminal was not achieved and start relay was de-energized. Low stage locked out for 30 minutes.
CODE: 77.
RESULT: High Stage Did Not Start.
FIX: Specified start voltage at VS terminal was not achieved in high stage. Start relay was de-energized after 1 second.
RESULT: High Stage Did Not Start.
FIX: Specified start voltage at VS terminal was not achieved in high stage. Start relay was de-energized after 1 second.
CODE: 78.
RESULT: High Stage Did Not Start 3 times.
FIX: For 3 consecutive high stage starts, the specified start voltage at VS terminal was not achieved and start relay was de-energized. High stage locked out for 30 minutes.
RESULT: High Stage Did Not Start 3 times.
FIX: For 3 consecutive high stage starts, the specified start voltage at VS terminal was not achieved and start relay was de-energized. High stage locked out for 30 minutes.
CODE: 81.
RESULT: Low Stage Thermal Lockout.
FIX: Thermal cutout occurs in three consecutive low/high stage cycles. Low stage locked out 4 hours or until 24v power recycled.
RESULT: Low Stage Thermal Lockout.
FIX: Thermal cutout occurs in three consecutive low/high stage cycles. Low stage locked out 4 hours or until 24v power recycled.
CODE: 82.
RESULT: High Stage Thermal Lockout.
FIX: Thermal Lockout occurs in three consecutive high/low stage cycles. High stage locked out for 4 hours or until 24V power recycled.
RESULT: High Stage Thermal Lockout.
FIX: Thermal Lockout occurs in three consecutive high/low stage cycles. High stage locked out for 4 hours or until 24V power recycled.
See What Our Customers Are Saying:
Apr 12, 2019
On one of the coldest days of winter, our furnace stopped working. Our regular furnace company came and told us we had a CO2 leak and shut us off. Their quote for a new furnace was way too high and they couldn't even install it on the same day. TwinTech was recommended to us by a friend. We called and spoke to Dave who was very nice and knowledgeable. Grant showed up a short time later and a new furnace was installed the same day with no troubles at all. Best of all, we received a higher-end furnace than what was offered by our previous company and at a cheaper price. I would recommend TwinTech with no hesitation at all.
Apr 11, 2019
I installed a new furnace and Air conditioner with them. The installation is of high quality and according to standards. The guys are professional and reasonably priced.. I highly recommend them.
Apr 10, 2019
Had new furnace installed and ran into some difficulties but the contractor responded in a timely and efficient manner - after further service calls were made, a reasonable resolution was found.
Apr 8, 2019
The work was done quickly efficiently neatly and professionally. Pleased with the service, information, product, and the company.
Apr 1, 2019
Great sales member named Dave came in told us some amazing items and how they would be priced installed an all. We couldnt believe it! The next day the ac was installed, that day one employee named Greg told us that our furnace was working way to hard and was causing us to use way too much gas. So two days later they came in an installed a new furnace!
Apr 1, 2019
Installation was done quickly and professionally. The new furnace is quiet and provides even heat.
Mar 3, 2019
They removed and discarded old furnace. Installed new furnace. Installed air intake pipe, that had never been installed by builder, no charge. Replaced loose hose on floor with hard pipe and rerouted it to drain, no charge. Almost 33% cheaper then quote from Enercare, which was the company we dealt with and had insurance with for 8 years. No yearly fee for cleaning/insurance, saves 300 a year. Courteous, professional, fast, and friendly. My wife and I have been recommending them to everyone we know and meet, and will continue to do so. Thanks for everything, Twintech!!!
Mar 4, 2019
This company was great to deal with. Our furnace went down and they installed a new furnace the next day with a lot of professionalism!
Feb 22, 2019
Finally! An honest company with highly knowledgeable and informative staff. Had a furnace service and found multiply errors in our system from an amateur installer. Very fair price to correct problems and will definitely use again.
Feb 16, 2019
Had to replace the heating & a/c unit in a condo apartment dwelling. this company recommended by the property manager and president of the condo building. found their workmanship and attention to details very good and very thorough. were able to resolve small problems and situations and happy to feel the heat in my unit. it's pricey, but happy was done by a very professional service. thank you.
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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