diff --git a/opencode/decisions.yaml b/opencode/decisions.yaml
index 5b83fb73..babc4cde 100644
--- a/opencode/decisions.yaml
+++ b/opencode/decisions.yaml
@@ -601,3 +601,24 @@ notes:
       - zigbee2mqtt
     pin: true
     status: superseded
+  - id: 2026-08-28-filter-plug-hardware-faulty-replacing
+    date: 2026-08-28
+    title: Filter plug hardware-faulty; replacing with Matter plugs
+    decision: "Filter plug (0xffffb40e060893d8) is hardware-faulty: downlink fails with 0xe1
+      despite clean re-pair and relocation; uplink/button/other devices work. Do not
+      re-diagnose. Being replaced by Kasa KP125M Matter (Wi-Fi) plugs; no Z2M re-pair.
+      Entity IDs change — re-point references."
+    rationale: Supersedes earlier note assuming a Zigbee replacement. Clean re-pair plus
+      relocation next to the coordinator both failed to resolve identical 0xe1 errors on
+      downlink-only commands; button and uplink work, no other device shares the fault.
+      Replacement is 4x Kasa KP125M Matter (Wi-Fi, energy monitoring). Commission via
+      Matter add-on; entity IDs change, so printer/health automations and dashboard tile
+      need re-pointing.
+    entities:
+      - switch.filter
+      - sensor.0xffffb40e060893d8_linkquality
+    integrations:
+      - matter
+      - zigbee2mqtt
+    pin: true
+    status: active