Durham Region Air Conditioning Repair, Service and Installation
In some cases air conditioning system repair can be rather complicated for an average user. However, some of the typical problems are not that serious and don't require much more than basic skills. Even if you don't feel like troubleshooting your Rheem air conditioner on your own, you may use the check list below to gain a better understanding of the issue and not let a service company take advantage of you.
rheem A/C error codes
CODE: 0- Standby.
RESULT: No command for unit operation.
FIX: Normal operation.
RESULT: No command for unit operation.
FIX: Normal operation.
CODE: c - First Stage Cooling.
RESULT: Unit has received a command for first stage cooling.
FIX: Normal operation.
RESULT: Unit has received a command for first stage cooling.
FIX: Normal operation.
CODE: c Flashing.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active.
FIX: The unit has received a command for first stage cooling during an active anti-short cycle timer or minimum run timer. Wait until unit timer has expired or press the TEST button to defeat short cycle delay..
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active.
FIX: The unit has received a command for first stage cooling during an active anti-short cycle timer or minimum run timer. Wait until unit timer has expired or press the TEST button to defeat short cycle delay..
CODE: C - Second Stage Cooling.
RESULT: Unit has received a command for second stage cooling.
FIX: Normal operation.
RESULT: Unit has received a command for second stage cooling.
FIX: Normal operation.
CODE: C Flashing.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active.
FIX: The unit has received a command for second stage cooling during an active anti-short cycle timer or minimum run timer. Wait unit timer has expired or press the TEST button to defeat short cycle delay.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active.
FIX: The unit has received a command for second stage cooling during an active anti-short cycle timer or minimum run timer. Wait unit timer has expired or press the TEST button to defeat short cycle delay.
CODE: h - First Stage Heat Pump.
RESULT: Unit has received a command for first stage heat pump.
FIX: Normal operation.
RESULT: Unit has received a command for first stage heat pump.
FIX: Normal operation.
CODE: h Flashing.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) action.
FIX: The unit has received a command for first stage heat pump during an active anti-short cycle timer or minimum run time. Wait unit timer has expired or press the TEST button to defeat short cycle delay.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) action.
FIX: The unit has received a command for first stage heat pump during an active anti-short cycle timer or minimum run time. Wait unit timer has expired or press the TEST button to defeat short cycle delay.
CODE: H - Second Stage Heat Pum.
RESULT: Unit has received a command for second stage heat pump.
FIX: Normal operation.
RESULT: Unit has received a command for second stage heat pump.
FIX: Normal operation.
CODE: H Flashing.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active.
FIX: The unit has received a command for second stage heat pump during an active anti-short cycle timer or minimum run timer. Wait unit timer has expired or press the TEST button to defeat short cycle delay.
RESULT: Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active.
FIX: The unit has received a command for second stage heat pump during an active anti-short cycle timer or minimum run timer. Wait unit timer has expired or press the TEST button to defeat short cycle delay.
CODE: d - Defrost Active.
RESULT: The unit is undergoing a defrost cycle.
FIX: Normal operation.
RESULT: The unit is undergoing a defrost cycle.
FIX: Normal operation.
CODE: t - Test Mod.
RESULT: Test Mod.
FIX: The ICC is in TEST mode.
RESULT: Test Mod.
FIX: The ICC is in TEST mode.
CODE: P - Protector Trip.
RESULT: A command for compressor operation is present but no current is measured to the compressor.
FIX: Motor protector open.
RESULT: A command for compressor operation is present but no current is measured to the compressor.
FIX: Motor protector open.
CODE: 01 - Long Run Time (Compressor).
RESULT: The compressor has continuously run for more than 18 hours in the cooling mode.
FIX: Low refrigerant charge. Air ducts have substantial leakage. Dirty indoor air filter. Dirty outdoor coil.
RESULT: The compressor has continuously run for more than 18 hours in the cooling mode.
FIX: Low refrigerant charge. Air ducts have substantial leakage. Dirty indoor air filter. Dirty outdoor coil.
CODE: 02 - High Pressure.
RESULT: Compressor limit has opened four (4) times within a call for operation.
FIX: Outdoor coil is dirty (cooling mode). Outdoor fan is not running (cooling mode). Dirty indoor coil or filter (heating mode). Indoor blower is not running (heating mode). Liquid line restriction. Excessive refrigerant charge.
RESULT: Compressor limit has opened four (4) times within a call for operation.
FIX: Outdoor coil is dirty (cooling mode). Outdoor fan is not running (cooling mode). Dirty indoor coil or filter (heating mode). Indoor blower is not running (heating mode). Liquid line restriction. Excessive refrigerant charge.
CODE: 03 - Short Cycling.
RESULT: ICC detects the run time for the past four (4) compressor or cycles is less than three (3) minutes each .
FIX: Check thermostat wire connection. Check thermostat location in zone..
RESULT: ICC detects the run time for the past four (4) compressor or cycles is less than three (3) minutes each .
FIX: Check thermostat wire connection. Check thermostat location in zone..
CODE: L4 - Locked Rotor.
RESULT: The ICC detects four (4) consecutive protector trips have occurred and the average run time for each trip is less than 15 seconds.
FIX: Bad run capacitor. Low line voltage. Excessive refrigerant in compressor. Seized bearings in compressor.
RESULT: The ICC detects four (4) consecutive protector trips have occurred and the average run time for each trip is less than 15 seconds.
FIX: Bad run capacitor. Low line voltage. Excessive refrigerant in compressor. Seized bearings in compressor.
CODE: 05 - Open circuit (Compressor Will not Run).
RESULT: The ICC has had a protector trip for longer than 4 hours.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity. Check for open compressor internal protector.
RESULT: The ICC has had a protector trip for longer than 4 hours.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity. Check for open compressor internal protector.
CODE: 06 - Compressor Open Start Circuit.
RESULT: The ICC detects current in the Run circuit but not in the Start circuit of the compressor.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
RESULT: The ICC detects current in the Run circuit but not in the Start circuit of the compressor.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
CODE: L6 - Compressor Open Start Circuit.
RESULT: The ICC detects current in the Run circuit but not in the Start circuit of the compressor four (4) times in one compressor call.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
RESULT: The ICC detects current in the Run circuit but not in the Start circuit of the compressor four (4) times in one compressor call.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
CODE: 07 - Compressor Open Run Circuit.
RESULT: The ICC detects current in the Start circuit but not in the Run circuit of the compressor.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
RESULT: The ICC detects current in the Start circuit but not in the Run circuit of the compressor.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
CODE: L7 - Compressor Open Run Circuit.
RESULT: The ICC detects current in the Start circuit but not in the Run circuit of the compressor four (4) times in one compressor call.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
RESULT: The ICC detects current in the Start circuit but not in the Run circuit of the compressor four (4) times in one compressor call.
FIX: Check for damaged, miswired, or wrong run capacitor. Check for broken Wires, loose connectors, or miswired compressor. Check compressor windings for continuity.
CODE: 09 - Low Secondary Volts.
RESULT: The secondary voltage at R and C is below 18VAC.
FIX: Control transformer overloaded. Low line voltage.
RESULT: The secondary voltage at R and C is below 18VAC.
FIX: Control transformer overloaded. Low line voltage.
CODE: 21 - Low Pressure Control Open.
RESULT: The ICC detects the LPC is open. Note: The low pressure control is ignored for the first 90 seconds of compressor operation .
FIX: Unit has low refrigerant charge. Indoor coil is frozen (cooling mode). Dirty indoor coil or filter (cooling mode). Indoor blower is not running (cooling mode). Outdoor coil is frozen (heating mode). Expansion valve is not operating correctly.
RESULT: The ICC detects the LPC is open. Note: The low pressure control is ignored for the first 90 seconds of compressor operation .
FIX: Unit has low refrigerant charge. Indoor coil is frozen (cooling mode). Dirty indoor coil or filter (cooling mode). Indoor blower is not running (cooling mode). Outdoor coil is frozen (heating mode). Expansion valve is not operating correctly.
CODE: L21 Flashing.
RESULT: Active Protection, Low Pressure Control Trip.
FIX: LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 21.
RESULT: Active Protection, Low Pressure Control Trip.
FIX: LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 21.
CODE: 27.
RESULT: Low Line Voltage or No Line Voltage Fault.
FIX: Check incoming line voltage to the disconnect and unit. Check wiring connections.
RESULT: Low Line Voltage or No Line Voltage Fault.
FIX: Check incoming line voltage to the disconnect and unit. Check wiring connections.
CODE: 28.
RESULT: High Line Voltage Fault.
FIX: Check line voltage.
RESULT: High Line Voltage Fault.
FIX: Check line voltage.
CODE: 29.
RESULT: High Pressure Control Open. The ICC detects the HPC is open.
FIX: Outdoor coil is dirty (cooling mode). Outdoor fan is not running (cooling mode). Dirty indoor coil or filter (heating mode). Indoor blower is not running (heating mode). Liquid line restriction. Excessive refrigerant charge.
RESULT: High Pressure Control Open. The ICC detects the HPC is open.
FIX: Outdoor coil is dirty (cooling mode). Outdoor fan is not running (cooling mode). Dirty indoor coil or filter (heating mode). Indoor blower is not running (heating mode). Liquid line restriction. Excessive refrigerant charge.
CODE: L29 Flashing - Active Protection.
RESULT: High Pressure Control Trip.
FIX: LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 29.
RESULT: High Pressure Control Trip.
FIX: LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 29.
CODE: 30 - Fuse Open.
RESULT: The ICC detects the on-board fuse is open.
FIX: The 3 amp fuse on the ICC is open. Low voltage Wiring at R and C is damaged or miswired.
RESULT: The ICC detects the on-board fuse is open.
FIX: The 3 amp fuse on the ICC is open. Low voltage Wiring at R and C is damaged or miswired.
CODE: 80 - Low Air Flow.
RESULT: The ICC detects that the indoor unit is not providing the minimum airflow requirements.
FIX: Misappliedwrong indoor air mover - replace With properly sized unit.
RESULT: The ICC detects that the indoor unit is not providing the minimum airflow requirements.
FIX: Misappliedwrong indoor air mover - replace With properly sized unit.
CODE: 83 - Condenser Coil Temperature Fault.
RESULT: The sensor detects an abnormally low or high coil temperature.
FIX: Replace the sensor. Check sensor is installed correctly on control.
RESULT: The sensor detects an abnormally low or high coil temperature.
FIX: Replace the sensor. Check sensor is installed correctly on control.
CODE: 84 - Outdoor Ambient Temperature Fault.
RESULT: The sensor detects an abnormally low or high outdoor ambient temperature.
FIX: Check unit placement - If the outdoor unit is in a high temperature area, wait until the ambient temperature drops and check sensor reading. Replace the sensor. Check sensor is installed correctly on control.
RESULT: The sensor detects an abnormally low or high outdoor ambient temperature.
FIX: Check unit placement - If the outdoor unit is in a high temperature area, wait until the ambient temperature drops and check sensor reading. Replace the sensor. Check sensor is installed correctly on control.
CODE: 93 - Internal Control Fault.
RESULT: The control is not functioning properly.
FIX: Check control for proper system Operation. Replace control.
RESULT: The control is not functioning properly.
FIX: Check control for proper system Operation. Replace control.
CODE: d1.
RESULT: N0 Shared Data.
FIX: Replace memory card With correct system information.
RESULT: N0 Shared Data.
FIX: Replace memory card With correct system information.
CODE: d3 - Airflow CFM Mismatch.
RESULT: The indoor air mover (air handler/furnace) cannot supply the required airflow for proper system operation.
FIX: Misappliedwrong indoor air mover-replace With properly sized air handler/furnace.
RESULT: The indoor air mover (air handler/furnace) cannot supply the required airflow for proper system operation.
FIX: Misappliedwrong indoor air mover-replace With properly sized air handler/furnace.
CODE: d4 - (Device) Memory Card Invalid for Device.
RESULT: The data in the memory card inserted into the control board does not match the data in the control.
FIX: Check memory card to ensure it matches device. Check if memory card is present.
RESULT: The data in the memory card inserted into the control board does not match the data in the control.
FIX: Check memory card to ensure it matches device. Check if memory card is present.
CODE: d8 - Old Shared Data.
RESULT: System data is obsolete.
FIX: If system Will not operate, order new memory card to update system information.
RESULT: System data is obsolete.
FIX: If system Will not operate, order new memory card to update system information.
See What Our Customers Are Saying:
Jun 11, 2019
Great team of guys came to do the work. Very professional. Arrived on time worked very efficiently and were very clean. They answered any questions we had without hesitation. The air conditioner works great and is so quiet. I highly recommend them and they don't try to up-sell anything right from the start.
May 10, 2019
The service was prompt, professional and very courteous. Competitive price. Would highly recommend this company.
Jul 20, 2019
Excellent workmanship, and quick response. Would recommend Twintech to anyone.
Nov 11, 2019
My existing 15-yr old A/C went down on me during the first major heatwave of the season. Researched my options, as well as a few different installers, and decided on Twintech.
They gave me confidence right from the beginning. Extremely knowledgeable. Their communication was excellent - always responded to questions quickly. Given we were in a heatwave, they were fully booked. However, within days they were able to fit me in due to a cancellation. Upon learning that the Amana unit I was getting installed was on backorder, TwinTech went to bat for me with the manufacturer and was able to get me the next model up within a day, for the same price - Amazing!
As far as the installation was concerned, I couldnt be more impressed. These guys were clearly very experienced and did a fantastic job. Very clean, polite, timely & informative. They even thoroughly sealed all the exposed gaps in my ductwork. Ive had plenty of heating and cooling work done in the past and have never used the same contractor twice because Ive never been very impressed. However, from now on, Ill always be contacting Twintech first!
Jun 19, 2019
They were very friendly and took care of everything. The install looks great (and works great), they were very knowledgeable. Installed our a/c efficiently despite the difficult install location both inside and outside and they made it work.
Jun 12, 2019
Phenomenal service, so glad I found these guys a few years back after being "hosed" badly by 3 other companies. I've recommended them to so many, and they all are so thankful.
May 1, 2019
This company is fantastic. Dave came out and gave me a very honest and reasonable quote, unlike a quote received from another company. I had a bunch of questions that were easily answered and when I had questions regarding heating/cooling a previously unheated room above the Garage, Dave arranged for Greg to come out for an assessment of this new space and gave me his recommendation along with his professional thoughts on all of my options.
These guys have been nothing but Professional, honest and helpful along the way. I can't recall the two other guys doing the install, but they were great as well. Good workmanship, everything was cleaned up and everything functions as promised. I could go on and on about my experience, but it's all positive so what more could you want?
Give them a call, see for yourself. If I had to buy another furnace/AC or heat pump, they'd be my first call.
Apr 16, 2019
I hired twin tech to convert my townhouse heating from electric to gas and install a furnace and a/c unit. I had talked with many other vendors, and received several quotes, but chose them, and very happy I did. Here are some of the reasons why:
1. They were realistic about the timeline for the work, when they could start and how long it would take. (They said upfront, it was their busy season and would need to get back to me in 3 weeks, which they did):
2. They had a quote with options for me. They were clear about the entertainment of what they would and would not do (theyd build duct work, id need another contractor to box in ductwork). This allowed me to plan as I was my own general contractor for my renovations).
3. They spoke to me in a language I understood, neither too technical nor too simple. They answered all my questions as I had them. Everyone is so lovely to work with, the sales team and the contractors who are worked in my home.
4. Its been 4 m since the work was complete. They still answer my emails and my furnace is working very well!
I unabashedly recommend! Price, customer care and quality workmanship were all amazing!
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.
See What Our Customers Are Saying:
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.
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