Durham Region Air Conditioning Repair, Service and Installation
If you're looking for help fixing your Heil furnace, look no further! Our comprehensive Heil furnace repair guide will explain common issues, provide troubleshooting tips, and show you how to read your model's error codes..
CODE: Heartbeat.
RESULT: Control has 24 VAC power.
RESULT: Control has 24 VAC power.
CODE: 2 Flashes.
RESULT: Pressure switch did not open, check for obstructed pressure tubing.
RESULT: Pressure switch did not open, check for obstructed pressure tubing.
CODE: 3 Flashes.
RESULT: Pressure switch did not close, or re-opened- Check for: excessive wind, proper vent size, defective inducer motor, low inducer voltage, defective pressure switch, inadequate combustion air supply, disconnected or obstructed pressure tubing, low inlet gas pressure, restricted vent, condensate clogged.
RESULT: Pressure switch did not close, or re-opened- Check for: excessive wind, proper vent size, defective inducer motor, low inducer voltage, defective pressure switch, inadequate combustion air supply, disconnected or obstructed pressure tubing, low inlet gas pressure, restricted vent, condensate clogged.
CODE: 4 Flashes.
RESULT: Limit circuit fault-a limit or flame rollout is open. Check for: restricted vent, proper vent sizing, loose blower wheel, excessive wind, dirty filter, defective blower motor, defective switch or connections, inadequate combustion air supply.
RESULT: Limit circuit fault-a limit or flame rollout is open. Check for: restricted vent, proper vent sizing, loose blower wheel, excessive wind, dirty filter, defective blower motor, defective switch or connections, inadequate combustion air supply.
CODE: 5 Flashes.
RESULT: Abnormal flame proving signal-Flame is proved while gas valve is de-energized. Check for: leaky gas valve, stuck open gas valve.
RESULT: Abnormal flame proving signal-Flame is proved while gas valve is de-energized. Check for: leaky gas valve, stuck open gas valve.
CODE: 6 Flashes.
RESULT: Failure to ignite or flame sense lost while running. Check for: Flame sensor must not be grounded, low inlet gas pressure, oxide buildup on flame sensor, Manual valve shut off, proper flame sense microamps, gas valve defective or gas valve turned off, defective hot surface igniter, control ground continuity, Inadequate flame carryover or rough ignition, green/yellow wire MUST be connected to furnace sheet metal.
RESULT: Failure to ignite or flame sense lost while running. Check for: Flame sensor must not be grounded, low inlet gas pressure, oxide buildup on flame sensor, Manual valve shut off, proper flame sense microamps, gas valve defective or gas valve turned off, defective hot surface igniter, control ground continuity, Inadequate flame carryover or rough ignition, green/yellow wire MUST be connected to furnace sheet metal.
CODE: 7 Flashes.
RESULT: Limit circuit lockout- Lockout occurs if the limit or flame rollout is open longer than 3 minutes. Control will auto reset after 3 hours. Refer to #4.
RESULT: Limit circuit lockout- Lockout occurs if the limit or flame rollout is open longer than 3 minutes. Control will auto reset after 3 hours. Refer to #4.
CODE: 8 Flashes.
RESULT: Gas heating lockout-Control will NOT auto reset. Check for: mis-wired gas valve, defective control valve.
RESULT: Gas heating lockout-Control will NOT auto reset. Check for: mis-wired gas valve, defective control valve.
CODE: 10 Flashes.
RESULT: Polarity-Line voltage, polarity reversed. If twinned, refer to twinning kit instructions.
RESULT: Polarity-Line voltage, polarity reversed. If twinned, refer to twinning kit instructions.
CODE: 1 + 2 Flashes.
RESULT: Blower on after power up- Blower runs for 90 seconds, if unit is powered up during a call for heat (R-W closed) or (R-W) opens during blower on delay.
RESULT: Blower on after power up- Blower runs for 90 seconds, if unit is powered up during a call for heat (R-W closed) or (R-W) opens during blower on delay.
CODE: 6 + 1 Flashes.
RESULT: Ignition lockout- Control will auto-reset after 3 hours. Refer to #6.
RESULT: Ignition lockout- Control will auto-reset after 3 hours. Refer to #6.
CODE: LED Off.
RESULT: Secondary voltage fuse is open- Check for: door switch not closed, 115VAC at L1 and neutral, 24VAC RED and COM BLUE, 24V Fuse 3A, short circuit in secondary voltage (24VAC wiring).
RESULT: Secondary voltage fuse is open- Check for: door switch not closed, 115VAC at L1 and neutral, 24VAC RED and COM BLUE, 24V Fuse 3A, short circuit in secondary voltage (24VAC wiring).
CODE: LED On.
RESULT: Control circuitry lockout- Auto-reset after one hour.
RESULT: Control circuitry lockout- Auto-reset after one hour.
CODE: LED SOLID.
RESULT: Gas valve relay stuck open- Flame sense circuit failure, software check error, reset power to clear lockout, replace control if status code repeats.
RESULT: Gas valve relay stuck open- Flame sense circuit failure, software check error, reset power to clear lockout, replace control if status code repeats.
See What Our Customers Are Saying:
Apr 12, 2019
On one of the coldest days of winter, our furnace stopped working. Our regular furnace company came and told us we had a CO2 leak and shut us off. Their quote for a new furnace was way too high and they couldn't even install it on the same day. TwinTech was recommended to us by a friend. We called and spoke to Dave who was very nice and knowledgeable. Grant showed up a short time later and a new furnace was installed the same day with no troubles at all. Best of all, we received a higher-end furnace than what was offered by our previous company and at a cheaper price. I would recommend TwinTech with no hesitation at all.
Apr 11, 2019
I installed a new furnace and Air conditioner with them. The installation is of high quality and according to standards. The guys are professional and reasonably priced.. I highly recommend them.
Apr 10, 2019
Had new furnace installed and ran into some difficulties but the contractor responded in a timely and efficient manner - after further service calls were made, a reasonable resolution was found.
Apr 8, 2019
The work was done quickly efficiently neatly and professionally. Pleased with the service, information, product, and the company.
Apr 1, 2019
Great sales member named Dave came in told us some amazing items and how they would be priced installed an all. We couldnt believe it! The next day the ac was installed, that day one employee named Greg told us that our furnace was working way to hard and was causing us to use way too much gas. So two days later they came in an installed a new furnace!
Apr 1, 2019
Installation was done quickly and professionally. The new furnace is quiet and provides even heat.
Mar 3, 2019
They removed and discarded old furnace. Installed new furnace. Installed air intake pipe, that had never been installed by builder, no charge. Replaced loose hose on floor with hard pipe and rerouted it to drain, no charge. Almost 33% cheaper then quote from Enercare, which was the company we dealt with and had insurance with for 8 years. No yearly fee for cleaning/insurance, saves 300 a year. Courteous, professional, fast, and friendly. My wife and I have been recommending them to everyone we know and meet, and will continue to do so. Thanks for everything, Twintech!!!
Mar 4, 2019
This company was great to deal with. Our furnace went down and they installed a new furnace the next day with a lot of professionalism!
Feb 22, 2019
Finally! An honest company with highly knowledgeable and informative staff. Had a furnace service and found multiply errors in our system from an amateur installer. Very fair price to correct problems and will definitely use again.
Feb 16, 2019
Had to replace the heating & a/c unit in a condo apartment dwelling. this company recommended by the property manager and president of the condo building. found their workmanship and attention to details very good and very thorough. were able to resolve small problems and situations and happy to feel the heat in my unit. it's pricey, but happy was done by a very professional service. thank you.
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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- SUBMITTED BY:
- TWINTECH HEATING & COOLING
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- SUBMITTED BY:
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- SUBMITTED BY:
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- SUBMITTED BY:
- TWINTECH HEATING & COOLING
- - December 3, 2020
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