$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

CLICK HERE FOR A FREE QUOTATION

McQuay was established in 1933. She specialized in the supply and service of air conditioning, ventilation and heating equipment, as well as in the production of heating equipment - heat exchangers and radiators.


McQuay Furnace error codes are seen in three colors, red, green, and amber/yellow. Each color will also flash a specific number of times to signify a specific error. Breaking down each color, and number of flashes, will help you solve the problem you are having with your York Furnace.


CODE: SLOW GREEN FLASH
RESULT: Normal operation

CODE: SLOW AMBER FLASH
RESULT: Normal operation with call for heat

CODE: RAPID RED FLASH
RESULT: Twinning error, incorrect 24V phasing.
FIX: Check twinning wiring. Flame sense current is below 1.5 microamps

CODE: RAPID AMBER FLASH
RESULT: Check and clean flame sensor. Check for proper gas flow. Verify that current is greater than 1.5 microamps at flame current test pad.

CODE: 4 AMBER FLASHES
RESULT: The control is receiving a "Y" signal from the thermostat without a "G" signal, indicating improper thermostat wiring.

CODE: 1 RED FLASH
RESULT: This indicates that flame was sensed when there was not a call for heat.
FIX: The control will turn on both the inducer motor and supply air blower. A gas valve that leaks or is slow closing would typically cause this fault.

CODE: 2 RED FLASHES
RESULT: This indicates that the normally open pressure switch contacts are stuck in the closed position.
FIX: The control confirms these contacts are open at the beginning of each heat cycle. This would indicate a faulty pressure switch or miswiring. This indicates the normally open pressure switch contact did not close after the inducer was energized.

CODE: 3 RED FLASHES
RESULT: This could be caused by a number of problems: faulty inducer, blocked vent pipe broken pressure switch hose or faulty pressure switch.

CODE: 4 RED FLASHES
RESULT: This indicates that the main limit switch has opened its normally closed contacts.
FIX: The control will operate the supply air blower and inducer. This condition may be caused by: dirty filter, improperly sized duct system, incorrect blower speed setting, incorrect firing rate or faulty blower motor. Also, this fault code could be caused by a blown fuse located on the control board.

CODE: 5 RED FLASHES
RESULT: This fault is indicated if the normally closed contacts in the rollout switch opens.
FIX: The rollout control is manually reset. If it has opened, check for proper combustion air, proper inducer operation, and primary heat exchanger failure or burner problem. Be sure to reset the switch and cycle power (24 VAC) to the control after correcting the failure condition. Also, this fault code could be caused by a blown fuse located on the control board.

CODE: 6 RED FLASHES
RESULT: This indicates that after the unit was operating, the pressure switch opened 4 times during the call for heat.
FIX: If the main blower is in a "Delay on" mode, it will complete it, and any subsequent delay off period. The furnace will lock out for one hour and then restart.

CODE: 7 RED FLASHES
RESULT: This fault code indicates that the flame could not be established. This no-light condition occurred 3 times (2 retries) during the call for heat before locking out.
FIX: Low gas pressure, faulty gas valve, dirty or faulty flame sensor, faulty hot surface ignitor or burner problem may cause this. The furnace will lock out for one hour and then restart.

CODE: 8 RED FLASHES
RESULT: This fault is indicated if the flame is lost 5 times (4 recycles) during the heating cycle.
FIX: This could be caused by low gas pressure, dirty or faulty flame sensor or faulty gas valve. The furnace will lock out for one hour and then restart.

CODE: 9 RED FLASHES
RESULT: Indicates reversed line voltage polarity or grounding problem.
FIX: Both heating and cooling operations will be affected. check polarity at furnace and branch. Check furnace grounding. Check that flame probe is not shorted to chassis.

CODE: 10 RED FLASHES
RESULT: Flame sensed with no call for heat.
FIX: Check gas valve and gas valve wiring This indicates that a primary or auxiliary limit switch has opened its normally-closed contacts and has remained open for more than five minutes.

CODE: 11 RED FLASHES
RESULT: This condition is usually caused by a failed blower motor or blower wheel.
FIX: Cycle power (24 VAC) to the control to reset the hard lockout condition after correcting the failure condition.

CODE: 12 RED FLASHES
RESULT: This code indicates an open igniter circuit.
FIX: This could be a disconnected or loose wire or a cracked or broken igniter.

CODE: STEADY ON RED
RESULT: Control failure.
FIX: Replace control board.

CODE: 60-MINUTE AUTOMATIC RESET FROM LOCKOUT
RESULT: This control includes a "watchdog" type circuit that will reset from a lockout condition after 60 minutes. Operational faults 6, 7, 8 will be reset. This provides protection to an unoccupied structure if a temporary condition exists causing a furnace malfunction. An example would be a low incoming gas supply pressure preventing unit operation When the gas pressure is restored, at some point the "watchdog" would restart the unit and provide heat for the house.

CODE: IGNITION CONTROL FLAME SENSE LEVELS
RESULT: Normal flame sense current is approximately 3.7 microamps DC Low flame signal warning starts at 1.5 microamps. Low flame signal control lockout point is 0.1 microamps DC.


See What Our Customers Are Saying:

by Karen Morgan on Twintech Heating and Cooling

Once again Twin Tech came through and fixed my furnace. A young man by the name of Mitch came by tonight and he was so nice explained everything he was quick he was clean he turned off the lights even when he left the furnace room it’s just above and beyond Twin Tech always delivers and I just found out about them last year and I will use no one else but thanks again Mitch you are fantastic

by Richard Liu on Twintech Heating and Cooling

I had a problem with the Furnace (Armstrong ultra V) and Greg diagnosed it on the phone. Even told me what the issue was and I was able to fix it. This level of service from a Business that is almost unknown today.

If you require service, reach out to Greg. I will definitely use them in the future!

by Tony Forde on Twintech Heating and Cooling

We have been shopping for a heat pump for our home. We had 3 reps come in and make recommendations and provide a quote. Of the 3, Bob was so clearly so much more qualified, thorough and informed than the other two that the decision was a no brainer. As soon as we get our audit results Twintech will be installing our heat pump.

by Private User, Pickering on Twintech Heating and Cooling

knowledgeable sales person, did not try to up-sell unneeded features,
and was easily contacted to ensure customer satisfaction.
Installation was expertly done by friendly guys, everything explained for use of the products. Old products were removed and returned to rental company as part of the service. Follow up call was received to check all was well. This is my second time using this company as I was fully satisfied with my previous air conditioning unit installation

by Private User, Courtice on Twintech Heating and Cooling

Twintech recently installed a new furnace for me. Bob did a great job assessing what I had and needed. All details well explained including the importance of proper sizing of furnace and the value of multi stage heating and the variable speed blower. As a nurse, indoor air quality is a high priority so the variable speed motor running continuous is so good. 24/7 air cleaning. Greg did a great job on install, attention to detail so appreciated. Already notice such an improved comfort and heat. Thank you Twintech! You come as advertised. I will recommend to anyone in need of heating or cooling!

by Walter, Whitby on Twintech Heating and Cooling

We received various quotes from 4 different companies and right away, the prompt and thorough communication from Bob from TwinTech stood out. He introduced himself, sent sample sites and information, and always confirmed any agreed to dates and times.

Bob was friendly and extremely knowledgeable about the topic of HVAC and it was clear he was passionate about his profession. He approached the job as if he was installing in his own home.

Prior to the new furnace & A/C installation, our old units were loud and inefficient - having several rooms feeling too cold in the winter and too hot in the summer. After installing the recommended units, all rooms stay at a consistent temperature- even the finished basement.

I highly recommend the TwinTech team - just an outstanding job at a reasonable price point.

by Private User on Twintech Heating and Cooling

The experience with Twintech was great from the start. Bob the sales manager was friendly and professional and did not use any pressure tactics. He was very knowledgeable.
The installation was completed by the twin owners in about 6-7 hours. Clean quiet easy going didn't mind when I poked my head in to see progress. Highly recommend

by Private User on Twintech Heating and Cooling

Just choose Twintech!

I do not usually write reviews and should have done this a few days sooner. But I was and still am enjoying the increased comfort in my home from the new furnace installed by Twintech.

From my initial call and conversation with Bob, I already had a good feeling that I would like this company.

I was provided information, pictures of great quality work previously completed.

When Bob came for the inspection of the furnace he was amazing. He gave so much great advice and told me all the areas that his team would resolve. I was very impressed as some of what he had suggested I had only seen in Youtube videos. The honesty and options for payment made this a no brainer. I decided I would like Twintech to replace my furnace.

The work was scheduled promptly week and took place within half a day. Gregg came to install the new furnace. Again amazing they carried out all the work promised. What was left was the best I have seen and speaks to how they take pride in the work they do and deliver. Gregg was really polite and professional and the furnace in my basement is a work of art.

by Private User on Twintech Heating and Cooling

They were friendly, fast, clean, & answered any questions I had. They are also offering an interest free 12 month payment plan - that really helped me out since this was an unexpected expense.

by Jamie, Windsor on Twintech Heating and Cooling

I had Twintech heating install a new furnace and ac unit. Bob, the sales rep, the installation team of Greg and Mitch were a 10 across the board. They were never pushy, gave me time to think about it. Once we decided , they were there in 24hrs. Great company to deal with. And they were nearly 5k less than a competitors quote for a top of the line furnace/ac unit verse mid level.
I highly recommend Twintech heating to anyone interested in anything HVAC.

See What Our Customers Are Saying:

by Aaron on Twintech Heating and Cooling

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.

by Linda on Twintech Heating and Cooling

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!

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!

Heat Pumps: Heating and Cooling in One System

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - May 8, 2025

When it comes to maintaining year-round comfort in your home, few systems offer the convenience and efficiency of a heat pump. What sets heat pumps apart from traditional HVAC systems is their dual functionality—the ability to both heat and

Read More

What You Need to Know Before Buying a Heat Pump

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - November 13, 2023

Buying a heat pump is a significant decision that can impact your home's comfort and energy efficiency. Here are key factors to consider before purchasing a heat pump: Climate and Region: Heat pumps are most effective in moderate

Read More

Amana Heat Pumps for Sale in Ajax

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - August 26, 2025

Looking for a dependable, energy-efficient way to heat and cool your home year-round At Twintech Heating & Cooling, we proudly offer top-of-the-line Amana heat pumps to homeowners across the Durham Region and Toronto. With professional instal

Read More

Twintech - The Best Amana Heat Pump Installation in Toronto

  • SUBMITTED BY:
  • TWINTECH HEATING & COOLING
  • - September 22, 2025

When it comes to heating and cooling your home, choosing the right system is only half the job. To get the most out of your investment, you need expert installation from trusted professionals. At Twintech Heating & Cooling, we’re prou

Read More