LG CordZero R9Check FilterCheck Filter — cause and how to fix it
Error code: Check Filter
The R9 'Check Filter' error is often a false positive caused by a clogged HEPA filter or a dirty pressure sensor inside the intake.
How to fix CordZero R9 Check Filter
- 1
Remove and wash the filter thoroughly, then let it dry for 24 hours.
- 2
If the error remains, the pressure sensor module needs cleaning or replacement, typically costing $20-30.
What this repair uses
LG CordZero R9 HEPA filter and sensor kit
Take it out, clean it, and seat it again before you replace it. If the error stays, this is the part to change.
Frequently asked questions
What does LG CordZero R9 Check Filter mean?
The R9 'Check Filter' error is often a false positive caused by a clogged HEPA filter or a dirty pressure sensor inside the intake.
Is this a hard repair to do myself?
Most of the steps above take 20-40 minutes with basic tools like a screwdriver. If you'd rather not open the unit yourself, contact the official support line below instead.
What part do I need?
You'll need a LG CordZero R9 HEPA filter and sensor kit. Compatible aftermarket parts are widely available on AliExpress and typically cost $8-60 depending on the part.
How do I contact LG support?
LG has 400+ service centers across Korea. Book via the LG ThinQ app for door-to-door repair service without an appointment. Phone: 1544-7777
Official support
LG has 400+ service centers across Korea. Book via the LG ThinQ app for door-to-door repair service without an appointment.
Online support
Open support page →