Durham Region Air Conditioning Repair, Service and Installation
The flashing LEDs on your furnace will correspond to a specific fault code that is shown here on their diagnostic chart.
If you have a Trane furnace, then you have one of the most reliable heating systems in existence. However, even the most reliable furnace runs into problems from time to time, and this is why your Trane has included several error codes to help you find a given issue. However, if you're unfamiliar with error codes for furnaces, then you may be unaware of what these codes mean.
To get peace of mind, it's important that you take a look at typical Trane furnace error codes to you learn what these error codes mean so you can get your system the service it needs.
CODE: Flashing Slow
RESULT: Normal no call for heat.
FIX: This is only an issue if you have raised your thermostat and your furnace doesn't respond.
RESULT: Normal no call for heat.
FIX: This is only an issue if you have raised your thermostat and your furnace doesn't respond.
CODE: Flashing Fast
RESULT: Normal call for heat.
FIX: Only beware this if your furnace is continuously calling for heat and isn't responding to your thermostat..
RESULT: Normal call for heat.
FIX: Only beware this if your furnace is continuously calling for heat and isn't responding to your thermostat..
CODE: Continuous On
RESULT: Control panel issue.
FIX: Replace Control Panel.
RESULT: Control panel issue.
FIX: Replace Control Panel.
CODE: Continuous Off
RESULT: Check Power.
FIX: Check Power.
RESULT: Check Power.
FIX: Check Power.
CODE: 2 Flashes
RESULT: External Lockout (Retried or recycles exceeded).
FIX: Check for miswiring, clogged pilot tube, or humidity in the unit.
RESULT: External Lockout (Retried or recycles exceeded).
FIX: Check for miswiring, clogged pilot tube, or humidity in the unit.
CODE: 3 Flashes
RESULT: Pressure Switch error.
FIX: Check if the drain tubes are full of moisture or obstructed with dirt.
RESULT: Pressure Switch error.
FIX: Check if the drain tubes are full of moisture or obstructed with dirt.
CODE: 4 Flashes
RESULT: Open high limit device.
FIX: The issue with thermal protection.
RESULT: Open high limit device.
FIX: The issue with thermal protection.
CODE: 5 Flashes
RESULT: Flame sensed when NO flame should be present.
FIX: Check for a leaky gas valve, stuck gas valve, or defective flame sensor.
RESULT: Flame sensed when NO flame should be present.
FIX: Check for a leaky gas valve, stuck gas valve, or defective flame sensor.
CODE: 6 Flashes
RESULT: 115 VAC power reversed polarity or poor grounding.
FIX: Correct line voltage polarity, check the wiring.
RESULT: 115 VAC power reversed polarity or poor grounding.
FIX: Correct line voltage polarity, check the wiring.
CODE: 7 Flashes
RESULT: Gas Valve circuit error.
FIX: Check your unit's gas valves for the issue.
RESULT: Gas Valve circuit error.
FIX: Check your unit's gas valves for the issue.
CODE: 8 Flashes
RESULT: Low Flame sens signal.
FIX: Check for flame sensor malfunction or low gas pressure.
RESULT: Low Flame sens signal.
FIX: Check for flame sensor malfunction or low gas pressure.
CODE: 9 Flashes
RESULT: Check Igniter.
FIX: Check igniter.
RESULT: Check Igniter.
FIX: Check igniter.
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!
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.
Aug 17, 2024
I returned from vacation to find my AC unit on the Fritz. After calling way too many places I connected with TwinTech. Ive used the company in the past for my furnace so I was happy when I recognized Greg at my front door. Hes great and the service is always top notch. Id highly recommend using twintech for honest, superior service in the Durham region. Thanks!
Aug 13, 2024
I called Twin Tech when my air conditioning stopped working. Greg came over to diagnose the issue - the same day. He was able to diagnose the issue and resolve it quite quickly. Although it was a quick fix, Greg was very thorough in explaining the issue and provided great advice. Not to mention, I felt very comfortable having Greg in my home - which I consider very important when hiring a service provider. Twin Tech will be my go-to from now on. Thank you!!
Aug 12, 2024
Just hired TwinTech Heating & Cooling to do an A/C Unit removal & reinstall to allow for landscaping access on the side of my house, and they were wonderful!
Bob, Greg & Mitch make a great team! Quick appointment times, super knowledgeable, expert troubleshooting capabilities & very customer service oriented.
I would highly recommend them for all of your HVAC needs! Great job guys!!