Sunster A2422 Remote Compatibility with 2409 and 2409Pro Heaters – Version Guide & Solutions

Introduction:
The A2422 remote underwent a significant upgrade after August 2025. The new A2422 is a temperature-sensing, wireless, two-way remote that allows full control of the heater just like the physical heater switch. It also includes CO monitoring to safely control heater on/off.

In contrast, the 2024 version of the A2422 only supports CO monitoring for heater on/off and does not have temperature sensing or two-way control features.

To use the new A2422’s remote functions, you must pair it with this year’s A2409Pro or A2409PW (WiFi version).

How to Identify the New A2409:

1. Power cycle the heater (turn off then on).
2. Check the version displayed:

Version ≥100 → This is the new 2409Pro (2025 release), supports the new A2422 remote.

Version 009 → Old version (2024), does not support temperature sensing two-way control and cannot perform OTA firmware updates via the app.

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Common Matching Issues and Solutions for 2409, 2409Pro, and A2422:

Type 1: Using old 2409/2409Pro with new A2422

Situation: Customers with a 2409 (no “Pro” on the switch) or 2409Pro purchased before June 2025 (stock in Czech/Australia), bought a new A2422 and cannot connect. Most choose the WiFi version to solve this.

Solution:

1. 2409 without FC/FD settings cannot connect to A2422.
2. 2409Pro with FC/FD settings can connect to old and new A2422, but only as a sensor, not as a remote.
3. Video Guide: Pairing new A2422 with last year’s 2409Pro works only as a sensor. During pairing, “SUC” will not appear; success is confirmed if the Bluetooth subdevice count increases in the 2409Pro configuration page.

 

Type 2: Old 2409 and A2422 purchased last year, now pairing fails

Situation: Both the heater and A2422 are from last year; pairing fails or the temperature control function is missing.

Solution:

1. If using an old 2409 with automatic start/stop, temperature control is unavailable. Set ct=1 to enable channel functionality. 
2. Video Guide: Old A2422 cannot connect to last year’s 2409. After performing this operation, re-add the A2422. Before operation: F number shows 01:01; after operation: it changes to 00:00.

 

Type 3: Old A2422 with new 2409PW

Situation: Customer wants to pair last year’s A2422 with this year’s 2409PW, fails.

Solution:

1. 2409Pro and 2409PW do not support old A2422.
2. Recommendation: Purchase the latest A2422 to ensure compatibility. We offer trade-in discounts for old units.

Need More Help?
If you encounter similar issues, post in our official facebook group or contact us at cs@sunster.tech. Our team will provide assistance.