When your Lennox heat pump model SL22KLV flashes code 135, it means you’ve got a low system charge issue. This is likely due to incorrect installation, maintenance, or a refrigerant leak. You’ll need to identify and fix the leak, then recover and recharge the system safely.
Don’t ignore this error, as it can lead to further damage and system inefficiencies – and there’s more to explore to get your heat pump running smoothly again.
Important Point
Causes of Low Refrigerant Charge
Because your Lennox heat pump is designed to operate within a specific refrigerant charge range, it is vital to identify the root causes of this issue.
Incorrectly sized or dirty air filters can restrict airflow, leading to low refrigerant pressure. This, in turn, can trigger the low-pressure switch, reducing system efficiency.
Furthermore, incorrect installation or maintenance can lead to low refrigerant charge, resulting in a communication error in the HVAC system.
Imperative to rule out these causes before investigating further, as they can have a significant impact on your system’s performance. By doing so, you’ll be able to identify the root cause and take corrective action to restore your Lennox heat pump’s peak operation.
Also, Read: Lennox SL22KLV Heat Pump Error Code 134: Thermostat Error Detected
Identifying Refrigerant Leaks
When troubleshooting a Lennox heat pump, identifying refrigerant leaks is a crucial step.
You’re looking for signs of refrigerant leaks, which can cause a low system charge. Certify all naked flames are removed or extinguished to prevent further refrigerant escape.
Use leak detection fluids suitable for the refrigerant type, avoiding those containing chlorine. Check the reversing valve, low-pressure side, and electrical components for signs of refrigerant leaks, as these areas are prone to refrigerant escape.
Be cautious with corrosive soaps that can damage certain metals. Perform a follow-up leak test before leaving the site to guarantee the repair is successful and prevent further refrigerant leaks.
Repairing Refrigerant Leaks
To guarantee a successful repair, you must recover all refrigerants safely; simultaneously, remove or extinguish naked flames to prevent igniting flammable refrigerants.
You’ll need to identify the source of the leak using electronic leak detectors or leak detection fluids with caution for flammable refrigerants.
Once you’ve located the leak, remove or extinguish naked flames and recover or isolate the refrigerant in the system to prevent additional damage.
When repairing the leak, certify they meet UL207 or ISO14903 standards to minimize future leaks.
After the repair, perform a follow-up leak test to confirm the system operates efficiently and the low system charge issue is resolved.
Also, Read: Lennox SL22KLV Heat Pump Error Code 132: Low Outdoor Temperature Triggering Freeze Protection Mode
Preventing Future Leaks
To prevent future leaks, you’ll want to focus on using braze-free fittings that meet UL207 or ISO14903 standards,
following the manufacturer’s guidelines for leak detection fluids to avoid corrosion, and taking other key precautions to guarantee a reliable refrigerant system.
Braze-Free Fittings Matter
Braze-free fittings conforming to UL207 or ISO14903 standards are your best defense against refrigerant leaks, which can lead to costly repairs, environmental harm, and safety hazards.
When installing heat pump models like the Lennox SL22KLV, you’ll want to inspect the connections and wiring for signs of wear or damage.
Check the low-pressure shutoff and resistance with a multimeter, measuring in ohms.
Don’t overlook the risk of refrigerant leaks, which can trigger Error Codes like 135.
By using braze-free fittings, you’ll minimize the risk of leaks and guarantee a safe, efficient system operation.
Take the time to guarantee all connections are secure to prevent future refrigerant leaks.
Follow Instructions Carefully
You can prevent refrigerant leaks by following a few key steps during heat pump installation and maintenance. To guarantee a successful repair, always follow the manufacturer’s instructions when using leak detection fluids to avoid corrosion. Prior to recharging, pressure-test the system with the appropriate purging gas and perform a follow-up leak test to confirm the repair was successful.
| Step | Action |
|---|---|
| 1 | Use braze-free fittings that conform to UL207 or ISO14903 |
| 2 | Use appropriate refrigerant recovery cylinders with pressure-relief valves and associated shut-off valves |
| 3 | Pressure-test the system with the appropriate purging gas and perform a follow-up leak test |
Minimize Corrosion Risks
Corrosion risks are minimized when refrigerant lines are installed with fittings that meet UL207 or ISO14903 standards.
To prevent future leaks, you should:
- Follow the manufacturer’s instructions when using leak detection fluids to avoid corrosion of certain metals.
- Prevent corrosive soaps from coming into contact with metals, as they can cause damage and lead to refrigerant leaks.
- Use only appropriate refrigerant recovery cylinders with pressure-relief valves and associated shut-off valves in good working order to prevent overfilling and other hazards.
Importance of Timely Repair
The timely repair of a Lennox heat pump error code is crucial for maintaining the overall efficiency and performance of the system.
You should prioritize resolving error code 135, as it can lead to high resistance, causing further damage and increasing total repair costs.
To diagnose the problem, inspect the float switch and verify it’s functioning correctly.
If you own a Three Top Lennox iComfort, you can use Lennox iComfort Thermostats to monitor the system’s performance and identify potential issues.
Furnace repair should be an urgent priority to resolve, guaranteeing your complete range of heating and cooling needs are met.
Also, Read: Lennox SL22KLV Heat Pump Error Code 131: Refrigerant Leak Detected in System
Solving Low Pressure Fault
When you encounter a low pressure fault in your Lennox heat pump, you’ll need to identify refrigerant leaks as a potential cause.
You’ll then need to take steps to repair those leaks to get your system back up and running.
Identify Refrigerant Leaks
You’re about to track down refrigerant leaks, a crucial step in solving low pressure faults.
A low-pressure switch tripped, indicating a low refrigerant charge.
Now, it’s time to identify the source of the leak:
- Use leak detection fluids suitable for the refrigerant type to check the reversing valve, low-pressure side, and electrical components for signs of refrigerant leaks.
- Recover all refrigerants safely and remove or extinguish naked flames to prevent igniting flammable refrigerants.
Repairing Refrigerant Leaks
Since the refrigerant leak has tripped the low-pressure switch, it’s crucial to repair the leak to resolve the low-pressure fault. A broken thermal expansion valve (TXV) is the likely cause, which can be resolved by replacing the TXV. Incorrectly sized or dirty air filters can also restrict airflow, leading to low refrigerant pressure.
| Causes of Low Pressure Fault | Solutions |
|---|---|
| Refrigerant Leaks | Replace TXV, repair leaks |
| Incorrect Air Filters | Replace with correctly sized filters |
| Incorrect Sizing | Guarantee correct refrigerant charge |
To repair refrigerant leaks, remove or extinguish naked flames, use leak detection fluids, and perform a follow-up leak test before leaving the site. Preventing future leaks requires the use of braze-free fittings that conform to UL207 or ISO14903, and pressure-testing the system with the appropriate purge gas.
Also, Read: Lennox SL22KLV Heat Pump Error Code 130: Inverter Board Malfunction Detected
Frequently Asked Questions
How to Clear Lennox Error Code?
To clear the error code, you’ll need to perform Heat Pump Troubleshooting and Error Code Analysis, checking the System Charge and detecting Refrigerant Leaks, which can cause Low Pressure Detection, affecting System Performance Monitoring and requiring Heat Pump Maintenance, Diagnostic Tool Usage, and Error Code Database reference.
What Is the Code E225 on a Lennox Furnace?
Imagine a pilot light struggling to stay lit; that’s code E225 on your Lennox furnace, indicating a faulty ignition or faulty sensors, potentially due to dirty furnace filters, igniter failure, or a gas leak, highlighting the need for thorough furnace maintenance and burner assembly inspection.
How Do You Reset a Lennox Heat Pump?
You reset a Lennox heat pump by switching to test mode, restarting the system, or rebooting low-voltage power; however, this won’t fix the underlying issue, so consult a technician to diagnose pump failure reasons and perform necessary maintenance.
What Is the Master Code for Lennox?
Did you know that over 90% of HVAC issues are resolved through simple troubleshooting? To access Lennox diagnostics, you’ll need the master password, which can be found in the error database or Lennox manual; this allows for factory reset, system initialization, and adjustment of system settings, configuration, and heat pump settings in diagnostic mode.
Conclusion
As you stand in front of your Lennox heat pump, error code 135 flashing on the screen, it’s clear: low system charge is holding you back from comfort. You’ve identified the issue, repaired the leaks, and taken preventive measures. Now, it’s time to solve this low-pressure fault once and for all.
Will you let a small refrigerant leak drain your wallet and your patience, or will you take control of your HVAC system today?
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