Durham Region Air Conditioning Repair, Service and Installation
Armstrong Air is the professional's choice in home heating & cooling. Including oil & gas furnaces, air conditioners, heat pumps, package units & air handlers.
CODE: E105.
RESULT: Device communication problem - No other devices on RS BUS (Communicating systems only).
FIX: Equipment is unable to communicate indicates numerous message errors. In most cases errors are related to electrical noise. Make sure high voltage power is separated from RSBus. Check for mis-wired and/or loose connections between the stat, indoor unit and outdoor unit. Check for a high voltage source of noise close to the system. Fault clears after communication is restored.
RESULT: Device communication problem - No other devices on RS BUS (Communicating systems only).
FIX: Equipment is unable to communicate indicates numerous message errors. In most cases errors are related to electrical noise. Make sure high voltage power is separated from RSBus. Check for mis-wired and/or loose connections between the stat, indoor unit and outdoor unit. Check for a high voltage source of noise close to the system. Fault clears after communication is restored.
CODE: E110.
RESULT: Low line voltage.
FIX: Line Voltage low (Voltage tower than nameplate rating). Check power line voltage and correct. Alarm clears 5 seconds after fault recovered.
RESULT: Low line voltage.
FIX: Line Voltage low (Voltage tower than nameplate rating). Check power line voltage and correct. Alarm clears 5 seconds after fault recovered.
CODE: E111.
RESULT: Line voltage polarity reversed.
FIX: Reverse line power voltage wiring. System resumes normal operation 5seconds after fault recovered.
RESULT: Line voltage polarity reversed.
FIX: Reverse line power voltage wiring. System resumes normal operation 5seconds after fault recovered.
CODE: E112.
RESULT: Ground not detected.
FIX: System shuts down. Provide proper earth ground. System resumes normal operation 5 seconds after fault recovered.
RESULT: Ground not detected.
FIX: System shuts down. Provide proper earth ground. System resumes normal operation 5 seconds after fault recovered.
CODE: E113.
RESULT: High line voltage.
FIX: Line Voltage high (Voltage higher than nameplate rating). Provide power voltage within proper range. System resumes normal operation 5seconds after fault recovered.
RESULT: High line voltage.
FIX: Line Voltage high (Voltage higher than nameplate rating). Provide power voltage within proper range. System resumes normal operation 5seconds after fault recovered.
CODE: E114.
RESULT: Line voltage frequency out of range.
FIX: No 60 Hertz power. Check voltage and line power frequency. Correct voltage and frequency problems. System resumes normal operation 5seconds after fault recovered.
RESULT: Line voltage frequency out of range.
FIX: No 60 Hertz power. Check voltage and line power frequency. Correct voltage and frequency problems. System resumes normal operation 5seconds after fault recovered.
CODE: E115.
RESULT: Low 24V.
FIX: 24 Volt Power high (Range is 18 to 30 Volts). Check and correct voltage. Check for additional power robbing equipment connected to system. May require installation of larger VA transformer to be installed in furnace/air handler. Clears after fault recovered.
RESULT: Low 24V.
FIX: 24 Volt Power high (Range is 18 to 30 Volts). Check and correct voltage. Check for additional power robbing equipment connected to system. May require installation of larger VA transformer to be installed in furnace/air handler. Clears after fault recovered.
CODE: E116.
RESULT: High 24V.
FIX: 24 Volt Power high (Range is 18 to 30 Volts) Check and correct voltage. Check for proper line voltage (120V 240V etc) to equipment. Clears when control senses proper voltage.
RESULT: High 24V.
FIX: 24 Volt Power high (Range is 18 to 30 Volts) Check and correct voltage. Check for proper line voltage (120V 240V etc) to equipment. Clears when control senses proper voltage.
CODE: E117.
RESULT: Poor ground detected (Warning only).
FIX: Provide proper grounding for unit. Check for proper earth ground to the system. Warming only will clear 30 seconds after fault recovered.
RESULT: Poor ground detected (Warning only).
FIX: Provide proper grounding for unit. Check for proper earth ground to the system. Warming only will clear 30 seconds after fault recovered.
CODE: E120.
RESULT: Unresponsive device (Communicating systems only).
FIX: Usually caused by delay in outdoor unit responding to indoor unit poling. Recycle power. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.
RESULT: Unresponsive device (Communicating systems only).
FIX: Usually caused by delay in outdoor unit responding to indoor unit poling. Recycle power. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.
CODE: E124.
RESULT: Active communicating thermostat signal missing for more than 3 minutes (Communicating systems only).
FIX: Equipment lost communication with the thermostat. Check four wiring connections, ohm wires, and cycle power at the thermostat. Alert stops all services and waits for heart beat message from thermostat (subnet controller). Cleared after valid thermostat (subnet) message is received.
RESULT: Active communicating thermostat signal missing for more than 3 minutes (Communicating systems only).
FIX: Equipment lost communication with the thermostat. Check four wiring connections, ohm wires, and cycle power at the thermostat. Alert stops all services and waits for heart beat message from thermostat (subnet controller). Cleared after valid thermostat (subnet) message is received.
CODE: E125.
RESULT: Control failed self check, internal error, failed hardware. Will restart if error recovers, Integrated control not communicating Covers hardware errors (flame sense circuit faults, pin shorts, etc).
FIX: Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Cleared 300 seconds after fault recovered.
RESULT: Control failed self check, internal error, failed hardware. Will restart if error recovers, Integrated control not communicating Covers hardware errors (flame sense circuit faults, pin shorts, etc).
FIX: Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Cleared 300 seconds after fault recovered.
CODE: E126.
RESULT: Control internal communication problem.
FIX: Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Cleared 300 seconds after fault recovered.
RESULT: Control internal communication problem.
FIX: Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Cleared 300 seconds after fault recovered.
CODE: E131.
RESULT: Corrupted control parameters (Verify configuration of system) (Communicating systems only).
FIX: Reconfigure the system. Replace control if heating or cooling is not available. Only applicable in the communicating mode not in startup. Exit from Commissioning and Execute Se+ factory Default mode. Control will still operate on default parameter settings.
RESULT: Corrupted control parameters (Verify configuration of system) (Communicating systems only).
FIX: Reconfigure the system. Replace control if heating or cooling is not available. Only applicable in the communicating mode not in startup. Exit from Commissioning and Execute Se+ factory Default mode. Control will still operate on default parameter settings.
CODE: E180.
RESULT: Outdoor air temperature sensor failure. Only shown if shorted or out of range (Communicating systems only).
FIX: Compare outdoor sensor resistance to temperature resistance chartsin unit installation instructions. Replace sensor pack if necessary. At beginning of (any) configuration, furnace or air handler control will sense outdoor air and discharge air temperature sensor(s) If detected (reading in range), appropriate feature will be set as installed and that could be seen in 'About' screen. In normal operation after control recognizes sensors, alarm will be sent if valid temperature reading is lost. To get rid of setting and alarm, redo configuration and make sure that temperature sensor is marked as not installed in indoor Unit 'About' screen. When indoor unit control is replaced thermostat will 'tell' new control if temperature sensor is in system or not. Clears 30 seconds after fault recovered.
RESULT: Outdoor air temperature sensor failure. Only shown if shorted or out of range (Communicating systems only).
FIX: Compare outdoor sensor resistance to temperature resistance chartsin unit installation instructions. Replace sensor pack if necessary. At beginning of (any) configuration, furnace or air handler control will sense outdoor air and discharge air temperature sensor(s) If detected (reading in range), appropriate feature will be set as installed and that could be seen in 'About' screen. In normal operation after control recognizes sensors, alarm will be sent if valid temperature reading is lost. To get rid of setting and alarm, redo configuration and make sure that temperature sensor is marked as not installed in indoor Unit 'About' screen. When indoor unit control is replaced thermostat will 'tell' new control if temperature sensor is in system or not. Clears 30 seconds after fault recovered.
CODE: E200.
RESULT: Hard Lock out - Rollout circuit open or previously open.
FIX: Correct cause of rollout trip or replace flame rollout switch. Test furnace operation. Cleared after fault recovered.
RESULT: Hard Lock out - Rollout circuit open or previously open.
FIX: Correct cause of rollout trip or replace flame rollout switch. Test furnace operation. Cleared after fault recovered.
CODE: E201.
RESULT: Indoor blower/communication failure. Unable to communicate with blower motor.
FIX: Indoor blower communication failure including power outage. Lost communication with indoor blower motor. Possible causes: motor not powered, loose wiring. Problem may be on control or motor side. Cleared after fault recovered.
RESULT: Indoor blower/communication failure. Unable to communicate with blower motor.
FIX: Indoor blower communication failure including power outage. Lost communication with indoor blower motor. Possible causes: motor not powered, loose wiring. Problem may be on control or motor side. Cleared after fault recovered.
CODE: E202.
RESULT: Indoor blower motor mismatch - indoor motor horsepower does not match unit capacity.
FIX: Incorrect appliance capacity code selected. Check for proper configuring under Unit Size Code for Furnace/Air Hander on configuration guide or in installation instructions. Cleared after the correct match is detected following a reset. (Remove thermostat from system while applying power and reprogramming).
RESULT: Indoor blower motor mismatch - indoor motor horsepower does not match unit capacity.
FIX: Incorrect appliance capacity code selected. Check for proper configuring under Unit Size Code for Furnace/Air Hander on configuration guide or in installation instructions. Cleared after the correct match is detected following a reset. (Remove thermostat from system while applying power and reprogramming).
CODE: E203.
RESULT: Appliance capacity size is NOT programmed. Invalid unit codes. Refer to configuration flow chart.
FIX: No appliance capacity code selected. Check for proper configuring under Unit Size Codes for Furnace on configuration guide or in installation instruction. Critical Alert Cleared after valid unit code is read following a reset (remove thermostat from system while applying power and reprogramming).
RESULT: Appliance capacity size is NOT programmed. Invalid unit codes. Refer to configuration flow chart.
FIX: No appliance capacity code selected. Check for proper configuring under Unit Size Codes for Furnace on configuration guide or in installation instruction. Critical Alert Cleared after valid unit code is read following a reset (remove thermostat from system while applying power and reprogramming).
CODE: E204.
RESULT: Gas valve mis-wired.
FIX: Check gas valve operation and wiring. Clears when repaired control.
RESULT: Gas valve mis-wired.
FIX: Check gas valve operation and wiring. Clears when repaired control.
CODE: E205.
RESULT: Gas valve control relay contact shorted.
FIX: Check wiring on control and gas valve. If wiring is correct replace control.
RESULT: Gas valve control relay contact shorted.
FIX: Check wiring on control and gas valve. If wiring is correct replace control.
CODE: E206.
RESULT: Gas valve second stage relay failure.
FIX: Furnace will operate on 1st stage for remainder of the heating demand. Will clear after fault recovered. If unable to operate 2nd stage replace control.
RESULT: Gas valve second stage relay failure.
FIX: Furnace will operate on 1st stage for remainder of the heating demand. Will clear after fault recovered. If unable to operate 2nd stage replace control.
CODE: E207.
RESULT: Hot surface igniter sensed open - Refer to troubleshooting.
FIX: Measure resistance of hot surface igniter. Replace if open or not within specified range found in 10M. Resumes normal operation after fault is cleared.
RESULT: Hot surface igniter sensed open - Refer to troubleshooting.
FIX: Measure resistance of hot surface igniter. Replace if open or not within specified range found in 10M. Resumes normal operation after fault is cleared.
CODE: E223.
RESULT: Low pressure switch failed open.
FIX: Check pressure (inches W.C) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.
RESULT: Low pressure switch failed open.
FIX: Check pressure (inches W.C) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.
CODE: E224.
RESULT: Low pressure switch failed closed. Refer to troubleshooting.
FIX: Check pressure (inches W.C) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.
RESULT: Low pressure switch failed closed. Refer to troubleshooting.
FIX: Check pressure (inches W.C) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.
CODE: E225.
RESULT: High pressure switch failed open. Refer to troubleshooting.
FIX: Check pressure(inches W.C) of high pressure switch closing on heatcall. Measure operating pressure (inches w.c. Inspect vent and combustion air inducer for correct operation and restriction Resumes normal operation after fault is cleared.
RESULT: High pressure switch failed open. Refer to troubleshooting.
FIX: Check pressure(inches W.C) of high pressure switch closing on heatcall. Measure operating pressure (inches w.c. Inspect vent and combustion air inducer for correct operation and restriction Resumes normal operation after fault is cleared.
CODE: E226.
RESULT: High pressure switch failed closed. Refer to troubleshooting.
FIX: Check operation of high pressure closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.
RESULT: High pressure switch failed closed. Refer to troubleshooting.
FIX: Check operation of high pressure closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.
See What Our Customers Are Saying:
Aug 26, 2022
This is the second time we have had Twintech to our house. A couple of summers ago they were in for an issue with our air conditioning. This time it was our furnace having an issue. It was shutting off randomly and not coming back on. Greg came right away and took the time to investigate thoroughly and explain what was going with the furnace. Both times I have been thoroughly impressed with their speed, customer service, and quality of work. I HIGHLY recommend Twintech.
Aug 24, 2022
Extremely happy.
So we were in no rush to replace our old units and took the time to do some research and get a number of quotes.
Twintech came in at around the middle of the pack for price but what convinced us to go with them was Bob, the representative that came to our house. Bob was by far the most professional of all the reps that we met with. He took the time to explain everything, what would work best for us and why. He really did seem very knowledgeable and enthusiastic about his stuff.
As promised on the day of install the crew showed up on time and got to work with minimal impact on us
..they were professional, clean, tidy and got the system up and running ahead of schedule...they made a couple of adjustments to the system to optimize it for our house.
The crew left the house clean and tidy.
Bob the rep showed up to check in and give us a few tips ..
It's been a week since install and all is good.
Our overall experience with Twintech has been excellent from start to finish and I wouldn't hesitate to recommend them.
Thank u.
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
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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