$49 / month O.A.C Including Install
$49 / month O.A.C Including Install

24 / 7 Emergency Service Available. Call Us Now: 1.844.894.6832

Durham Region Air Conditioning Repair, Service and Installation

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The flashing LEDs on your furnace will correspond to a specific fault code that is shown here on their diagnostic chart.


International Comfort Products Corporation (ICP) is a company that designs, manufactures and markets central air conditioning (HVAC) systems and gas and oil furnaces for use in homes and commercial buildings. It is a unit of Carrier Global Corporation and is headquartered in Lewisburg, Tennessee, United States.


CODE: LED Off
RESULT: 24 VAC or 115 VAC is off, fuse is open.
FIX: Check whether the door switch isn't closed or for a short circuit.

CODE: LED On
RESULT: Soft lockout, furnace control error, 1 hour delay. If code repeats immediately following power reset, then replace control.
FIX: Will auto-reset after 1 hour.

CODE: Heartbeat
RESULT: Normal operation.
FIX: N/A.

CODE: 2 Flashes
RESULT: Pressure switch closed when should be open.
FIX: Check for an obstruction in the pressure tubing.

CODE: 3 Flashes
RESULT: Pressure switch open when should be closed on single stage models. Low pressure switch open when should be closed on 2 stage.
FIX: Check for: excessive wind; proper vent size; defective inducer motor; defective pressure switch; inadequate combustion air supply; disconnected or obstructed pressure tubing; or restricted vent.

CODE: 4 Flashes
RESULT: Limit switch or rollout open.
FIX: Check for: restricted vent; proper vent sizing; loose blower wheel; excessive wind; dirty air filter; or defective blower.

CODE: 5 Flashes
RESULT: Flame sensed out of sequence.
FIX: Check for a leaky gas valve or a gas valve that is stuck open.

CODE: 6 Flashes
RESULT: Failure to ignite or flame sense lost while running.
FIX: Check for: an ungrounded flame sensor; defective hot surface ignitor; low inlet gas pressure; oxide buildup; manual valve shut off; control ground continuity; inadequate flame carryover; or rough ignition.

CODE: 6 + 1 Flashes
RESULT: Soft lockout - Max of 4 trials for ignition reached (3 hour delay).
FIX: Control will auto-reset after 3 hours.

CODE: 7 Flashes
RESULT: Soft lockout - Limit of roll-out switch open longer than 2 minutes (1 hr delay)(rollout switch requires manual reset).
FIX: A lockout will occur if the limit or flame rollout is open for longer than 3 minutes. Control will auto-reset after 3 hours.

CODE: 8 Flashes
RESULT: Permanent lockout - Gas valve relay contact stuck closed or mis-wired gas valve (power reset only).
FIX: Check for a miswired gas valve or a defective control valve.

CODE: 10 Flashes
RESULT: Line voltage polarity reversed. If twinned, refer to kit instructions.
FIX: Review instructions to correct polarity.


See What Our Customers Are Saying:

by Private User on Twintech Heating and Cooling

I had them replace my furnace last year. When it came time for the air conditioner this year, I did not hesitate to call Twintech again. I will also have them perform regular maintenance on them.

by Robert, Ajax on Twintech Heating and Cooling

We required a new HVAC replacement after running the old
system for 18 years.
Dave understood our requirements and gave us a quote that
covered all the necessary items.
Installation was fast and very tidy. Everything works as
it should. Our thanks to Greg, Mitch and others for their
excellent work. Recommend this family owned business to
anyone else, considering HVAC or other work.

by John Armstrong, Pickering on Twintech Heating and Cooling

I needed a new furnace and A/C to replace my 21 yr. old units, and went to the internet to view potential companies in May, I received 3 quotes,
and chose Twintech based on their salesman Dave who was very detailed and covered off everything on what Twintech was all about,
an extremely dedicated company with so many years of experience, and after reading the on line reviews I was sold on Twintech, who did not disappoint as the installation team were top notch with Greg leading,
I would highly recommend this company without any doubts, in my books they are first class all the way. Our new Amana furnace and A/C are working perfectly !

by Private User on Twintech Heating and Cooling

Flawless transaction. They did exactly what they promised, showed-up on time, cleaned-up, and were highly professional. Highly recommended.

by Bill Edmondson on Twintech Heating and Cooling

Salesperson and 2 man installation team were all professional and
knew their stuff. All three were friendly and helpful, answering all
my questions. The quality of their work demonstrated their experience
and expertise in their field.

by Private User on Twintech Heating and Cooling

A dear late cousin of mine recommended this company and I have been happy with the service.

by Private User on Twintech Heating and Cooling

We are very pleased with the work done by Twintech. They were very professional from start to finish. Dave came to our home and gave us a very competitive quote for new high efficiency furnace and air conditioner. The installers were very courteous and professional. We would highly recommend them.

by W1n5t0n1987! on Twintech Heating and Cooling

Great experience getting an old furnace replaced.
Sales Guy (Dave) was great - honest, responsive, and friendly.
The work itself was done quickly and we are very happy with the outcome, thank you! We recommend TwinTech!

by Private User on Twintech Heating and Cooling

This review is late coming so my apologies to the amazing Twin Tech team! I contacted Dave at Twin Tech for a quote this past Feb (as I was collecting a few) and his recommendation was excellent. From the first meeting with Dave to the team installing the new furnace, not once did i feel uncomfortable . The team were extremely professional yet personable and clean and tidy. Decent companies still exist!
The new furnace just purrs and its just amazing the difference it has made!
(PS my sibling ended up getting a furnace from them as well)

by Private User on Twintech Heating and Cooling

The service was Twintech was excellent.
Dave our salesperson was easy to talk to and was professional. The unit recommended meets our needs and budget.
Greg and his team arrived on time for the installation and even got rid of the garbage the contractors left in our furnace.
Would definitely recommend Twintech.

See What Our Customers Are Saying:

by Robert Rogers on Twintech Heating and Cooling

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.

by Robert Mizuno on Twintech Heating and Cooling

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!

by Ruth on Twintech Heating and Cooling

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!

by Anna Chin on Twintech Heating and Cooling

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!

by Connor Agnew on Twintech Heating and Cooling

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.

Why Are My AC Energy Bills Rising?

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - August 22, 2024

Rising AC energy bills can be caused by several factors. Here are some common reasons: 1. Aging Air Conditioner Older AC units tend to lose efficiency over time, requiring more energy to cool your home. 2. Poor Maintenance Lack of regular

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Why you should choose a career in HVAC

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - February 16, 2022

It can be hard to choose a career, especially if you are young or looking for a new path in life. And if you're one of those people who likes to know how things work instead of being in an office all day, why not consider a career in HVACHVAC, which

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What is a Heat Pump and How Does it Work?

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - July 31, 2019

A heat pump is an electrical device that pulls heat from one place and transfers it to another. This type of device has been used in Canada and around the world for decades. Both refrigerators and air conditioners use this type of device. Do not

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Guide to Replacing Your Furnace

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - November 24, 2024

Replacing your furnace is a significant investment in your home’s comfort and efficiency. Here’s a step-by-step guide to help you navigate the process: 1. Recognize When It’s Time for a New Furnace Age of the Furnace: Mos

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