Durham Region Air Conditioning Repair, Service and Installation
With this A/C troubleshooting guide, you can find problems with your system, fix it yourself. We will guide you through the process of identifying the problem and repairing your air conditioner.
Fault Display on the Dual 8 Numeral Tube of Outdoor Mainboard
CODE: E1.
RESULT: Actuation of high pressure switch.
FIX: Abnormality is detected when the contact of the high pressure switch opens for 3 sec. The system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
RESULT: Actuation of high pressure switch.
FIX: Abnormality is detected when the contact of the high pressure switch opens for 3 sec. The system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
CODE: E3.
RESULT: Actuation of low pressure switch.
FIX: When the unit runs more than 4 minutes or does not run, the low pressure switch opens for more than 3sec and the system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
RESULT: Actuation of low pressure switch.
FIX: When the unit runs more than 4 minutes or does not run, the low pressure switch opens for more than 3sec and the system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
CODE: E4.
RESULT: Air discharge high temperature protection of compressor.
FIX: The exhaust temperature is higher than 125C for more than 5sec, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90C for more than 5 sec, the compressor will re-start. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
RESULT: Air discharge high temperature protection of compressor.
FIX: The exhaust temperature is higher than 125C for more than 5sec, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90C for more than 5 sec, the compressor will re-start. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
CODE: F2.
RESULT: Malfunction of condenser temperature thermistor.
FIX: Malfunction of condenser temperature thermistor is detected when there is a short circuit or an open circuit in the condenser temperature thermistor for more than 5 sec. The system will be shut down. The reset for the malfunction of condenser temperature thermistor is automatic.
RESULT: Malfunction of condenser temperature thermistor.
FIX: Malfunction of condenser temperature thermistor is detected when there is a short circuit or an open circuit in the condenser temperature thermistor for more than 5 sec. The system will be shut down. The reset for the malfunction of condenser temperature thermistor is automatic.
CODE: F3.
RESULT: Malfunction of outdoor ambient temperature thermistor.
FIX: Malfunction outdoor ambient temperature thermistor is detected when there is a short circuit or an open circuit in the outdoor ambient temperature thermistor for more than 5 sec. The system will be shut down. The reset for the malfunction of condenser temperature thermistor is automatic.
RESULT: Malfunction of outdoor ambient temperature thermistor.
FIX: Malfunction outdoor ambient temperature thermistor is detected when there is a short circuit or an open circuit in the outdoor ambient temperature thermistor for more than 5 sec. The system will be shut down. The reset for the malfunction of condenser temperature thermistor is automatic.
CODE: F4.
RESULT: Malfunction of Exhaust Temp. Sensor.
FIX: If the exhaust temperature sensor is detected of open circuit 5 seconds successively after the compressor is started for 2 minutes or short circuit 5 seconds successively at any time .The system will be shut down. After the fault is eliminated, the system can automatically resume to operation.
RESULT: Malfunction of Exhaust Temp. Sensor.
FIX: If the exhaust temperature sensor is detected of open circuit 5 seconds successively after the compressor is started for 2 minutes or short circuit 5 seconds successively at any time .The system will be shut down. After the fault is eliminated, the system can automatically resume to operation.
CODE: ON.
RESULT: Normal operation.
FIX: Unit operating normally or in standby mode.
RESULT: Normal operation.
FIX: Unit operating normally or in standby mode.
CODE: H1.
RESULT: Defrost operation.
FIX 1: Power problem. Check control transformer power (24V). If power is available to demand control board and LED(s) do not light, replace control board.
FIX 2: Actuation of high pressure switch. Abnormality is detected when the contact of the high pressure switch opens for 3 sec. The system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
FIX 3: Actuation of low pressure switch. When the unit runs more than 4 minutes or does not run, the low pressure switch opens for more than3sec and the system will be shut down..The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
FIX 4: Air discharge high-temperature protection of compressor. The exhaust temperature is higher than 125C for more than 5s, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90C for more than 5s, the compressor will re-start. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
FIX 5: Malfunction of exhaust Temp. Sensor. If the exhaust temperature sensor is detected of open circuit 5 seconds successively after the compressor is started for 3 minutes or short circuit 5 seconds successively at any time The system will be shut down. After the fault is eliminated, the system can automatically resume to operation.
RESULT: Defrost operation.
FIX 1: Power problem. Check control transformer power (24V). If power is available to demand control board and LED(s) do not light, replace control board.
FIX 2: Actuation of high pressure switch. Abnormality is detected when the contact of the high pressure switch opens for 3 sec. The system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
FIX 3: Actuation of low pressure switch. When the unit runs more than 4 minutes or does not run, the low pressure switch opens for more than3sec and the system will be shut down..The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
FIX 4: Air discharge high-temperature protection of compressor. The exhaust temperature is higher than 125C for more than 5s, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90C for more than 5s, the compressor will re-start. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.
FIX 5: Malfunction of exhaust Temp. Sensor. If the exhaust temperature sensor is detected of open circuit 5 seconds successively after the compressor is started for 3 minutes or short circuit 5 seconds successively at any time The system will be shut down. After the fault is eliminated, the system can automatically resume to operation.
See What Our Customers Are Saying:
Aug 23, 2022
It was a refreshing experience interacting with the Twintech team. From Bob, the sales consultant, who articulated in layman's terms all the options available and reasons for making any selection. This was done without the prevailing pressure tactics so commonplace today.
Before proceeding Mitch, the technician, at our request conducted a service check on our 30 yr old furnace. His report was positive indicating no urgency to replace it. Again no pressure tactics.
Three days after first meeting with Bob, the installation team of Greg and
Spencer completed the installation within the planned time frame.
A very professional, courteous and transparent team which delivered on their promise. I highly recommend Twintech.
Aug 22, 2022
Initial contact with sales resulted in an immediate response, which led to a timely installation. Both sales and installers were all very professional. I have no hesitation in recommending TWINTECH.
Aug 21, 2022
I had a great experience with TwinTech. The company offered a reasonable quote, and performed a quick and clean installation. The installer Greg was experienced, professional and courteous. He explained the services he performed and gave recommendations on maintain the new furnace.
The salesman Bob was honest
and professional and educated me on how to achieve optimal performance.
All communication from them was quick and they came the following day. I was pleased with the service and would recommend them.
Aug 20, 2022
From quote, to installation, to follow up, Twintech provided excellent service. I would highly recommended their services.
Aug 19, 2022
I had a really great experience with these guys. The salesman Bob was clearly very knowledgeable about everything to do with heating and cooling a home, spent a lot of time with us going over the details of the job, never rushed us and came back after the install to make sure we were happy. The installation crew was excellent, they covered the floors all the way from outside down to the basement furnace room, kept the place clean, got the work done on time and were very friendly. Ive got 15 years in the contracting/ construction industry and these guys are one of the most professional companys Ive dealt with. Great company!
Aug 18, 2022
Had great service and clean-up was good. Was happy with my salesman. They were very friendly and helpful. I needed a new furnace as our was over 20 years old. The furnace and air-conditioner work great and they are very quiet. I am very pleased with the service and product I received.
Aug 17, 2022
Met with Dave for the sales process and he was great about explaining and going over everything to us. The install happened very quickly and the team were super professional and friendly. We are very happy with this company and their services and we definitely recommend them to others. Thankful my sister recommended them to me!
Aug 16, 2022
Reviews for Twintech were good, and they did not disappoint. After an initial visit to discuss the suitable AC unit for replacement, an installation date was available in just a couple of days, and everything was installed without a hitch. Highly recommended
Aug 16, 2022
Very pleased with the installation of our new furnace and A/C unit. From quotation stage to the completion of the job Twintech was very professional.
Thank you for a job well done.
Aug 15, 2022
My old water heater quit on me. I called TwinTech. In less than 4 days, I had my new water heater installed and the old one taken away. The whole process was quick, easy, pleasant, and well done. This is the third time I've dealt with TwinTech and I've been satisfied each time.
See What Our Customers Are Saying:
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!
Feb 18, 2025
Amazing experience with TwinTech Heating & Cooling! Their team was professional, knowledgeable, and efficient from start to finish. They installed my new furnace quickly and left everything spotless. The technicians took the time to explain everything and made sure I was comfortable with the system before they left. Great customer service and fair pricing. I highly recommend them for anyone needing HVAC services!
Feb 18, 2025
Great experience all around. Bob was sharp and easy to talk to, and Greg handled the installation perfectly. Would hire them again in a heartbeat.
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