diff --git a/identified.md b/identified.md
index 283f82c..6783567 100644
--- a/identified.md
+++ b/identified.md
@@ -22,10 +22,11 @@ analysis.
 | 38 | Internal Unit Temp | ×0.1 | °C | −2.2 – 21.8 | STATISTICAL | Tracks outdoor ambient +5°C offset; r=0.953 vs reg_39 — consistent with enclosure heat from inverter/compressor. AP mode label: "T3 Suction" |
 | 39 | Outdoor Ambient Temp | ×0.1 | °C | −5.5 – 17.4 | STATISTICAL | Range consistent with UK ambient over logging period. AP mode label: "Evaporator Temp" |
 | 40 | System Return Temp | ×0.1 | °C | 16.9 – 52.8 | CONFIRMED | Tracks Shelly return within −0.4°C during stable flow. Actual system return water temp (EWT). AP mode label: "T5 Return Temp" |
-| 45 | Discharge Gas Temp | ×0.1 | °C | 17.3 – 84.1 | STATISTICAL | Only register reaching >60°C; r=0.922 vs flow temp; mean 7.6°C above condensing temp. AP mode label: "T10 Discharge" |
+| 45 | Discharge Gas Temp | ×0.1 | °C | 17.3 – 84.1 | CONFIRMED | Only register reaching >60°C; r=0.922 vs flow temp; mean 7.6°C above condensing temp. AP mode label: "T10 Discharge" |
 | 47 | Flow Rate | ×0.01 | l/min | — | NAMED | Sika VVX20 flow meter built into unit |
-| 50 | Reported COP | ×0.01 | — | 2.75 – 5.97 | STATISTICAL | Mean 4.23 consistent with live COP; negative correlation with flow temp confirms higher lift → lower COP. Previously labelled "Suction Pressure" |
+| 50 | Suction | ×0.01 | — | 2.75 – 5.97 | CONFIRMED | Cross-checked with HP installer page labelled: "Suction (bar). Previously labelled "Reported COP" |
 | 51 | Compressor Speed | ×1 | % | 0 – 100 | STATISTICAL | Exact 0–100 range; correlates with compressor frequency |
+| 52 | Fan Suction | ×1 | Pa | - | CONFIRMED | Cross-check with HP installer page labelled: "Fan suction (Pa)" |
 | 53 | Compressor Frequency | ×0.1 | Hz | 0 – 60 | STATISTICAL | Raw 0–600 = 0–60 Hz; r=0.708 vs compressor speed % |
 | 64 | Heat Output | ×1 (signed Int16) | W | Observed: −8,870 to +6,745 (AdamLC 24h, 13 Apr 2026). Theoretical Int16: ±32,767 | CONFIRMED | r=0.999 vs flow×ΔT thermal calculation (heating, original identified.md analysis). Signed interpretation confirmed by two installations 13 Apr 2026: AdamLC defrost peaks −8,276 W / −8,870 W (raw 57,260 / 56,666); Stu startup transients −4 to −893 W. R48 phases during defrost validate reverse-cycle physics (3.85 bar equalized at entry, ~16 bar at peak-negative R64). |
 | 66 | Operating Mode | ×1 | enum | 0 – 3 | STATISTICAL | Discrete values 0/1/2/3 — likely Off / Heating / DHW / Defrost. Requires operational confirmation |
diff --git a/qsh-modbus-sniffer/CHANGELOG.md b/qsh-modbus-sniffer/CHANGELOG.md
index 3b68830..82cee62 100644
--- a/qsh-modbus-sniffer/CHANGELOG.md
+++ b/qsh-modbus-sniffer/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## 4.10.0 - 2026-07-26
+
+### Revise registers based on cross-validation
+
+Updated the following registers based on HP installer page
+`Cosy Modbus Reg 52` -> `Fan suction`
+`Cosy DHW Cylinder Temp` -> `Discharge Gas Temp`
+`Cosy Reported COP` -> `Suction`
+
 ## 4.9.0 - 2026-07-26
 
 ### Breaking
diff --git a/qsh-modbus-sniffer/config.yaml b/qsh-modbus-sniffer/config.yaml
index 7fb9e3b..987f6c3 100644
--- a/qsh-modbus-sniffer/config.yaml
+++ b/qsh-modbus-sniffer/config.yaml
@@ -1,6 +1,6 @@
 name: "QSH Modbus Sniffer"
 description: "Passive Modbus RTU sniffer for Octopus Cosy 6 heat pump. Captures all traffic between hub and outdoor unit via Waveshare RS485-to-WiFi gateway."
-version: "4.9.0"
+version: "4.10.0"
 slug: "qsh_modbus_sniffer"
 url: "https://github.com/stuartleeks/qsh-modbus-sniffer"
 arch:
diff --git a/qsh-modbus-sniffer/rootfs/opt/qsh/cosy6_decoder.py b/qsh-modbus-sniffer/rootfs/opt/qsh/cosy6_decoder.py
index a91b1fe..65959b3 100644
--- a/qsh-modbus-sniffer/rootfs/opt/qsh/cosy6_decoder.py
+++ b/qsh-modbus-sniffer/rootfs/opt/qsh/cosy6_decoder.py
@@ -160,12 +160,11 @@
     # Previously misnamed "Condenser Mid Temp" — regs 29/30 are the actual
     # condenser (refrigerant) sensors. This is the water side.
     44: {"name": "T9 Flow Temp",          "scale": 0.1,  "unit": "°C",    "icon": "mdi:thermometer-water",    "class": "temperature"},
-    # CONFIRMED: DHW cylinder temp. During active DHW cycle (2026-02-18
-    # 06:30-08:21), read 52.4°C rising to 54.4°C toward 55°C setpoint.
-    # Range 22-82°C spans ambient (off) through DHW boost temperatures.
+    # CONFIRMED: Compressor discharge gas temp. Matches HP installer page.
+    # Previously misnamed "DHW Cylinder Temp" - not available via Modbus
     # Previously misnamed "Compressor Shell Temp" — reg 56 is the actual
     # discharge temp (40.8°C), confirming this is NOT a compressor sensor.
-    45: {"name": "DHW Cylinder Temp",     "scale": 0.1,  "unit": "°C",    "icon": "mdi:thermometer-high",     "class": "temperature"},
+    45: {"name": "Discharge Gas Temp",     "scale": 0.1,  "unit": "°C",    "icon": "mdi:thermometer-high",     "class": "temperature"},
     # CONFIRMED (defrost validated, R290 cross-check): Primary frost signal.
     # Steady state 5.8-7.8°C. Drops to 0°C at defrost trigger.
     # Spikes to 37-55°C during hot gas defrost, decays as ice melts.
@@ -206,16 +205,12 @@
     # 13 bar → 35.1°C (matches condenser inlet R29). 5 bar → 4.8°C (matches
     # equalized evaporator R55). Closed.
     48: {"name": "Discharge Pressure",   "scale": 0.01, "unit": "bar",   "icon": "mdi:gauge-full",           "class": "pressure"},
-    # STATISTICAL (identified.md + 2026-04-05 analysis): Reported COP.
-    # Raw range 236-635 at scale ×0.01 = 2.36-6.35 (unitless ratio).
-    # identified.md: mean 4.23, negative correlation with flow temp (higher
-    # lift → lower COP). Cross-validated: reg_64/reg_27 implied COP ≈ 3.94,
-    # Δ = 7% from reg_50 — within measurement uncertainty.
-    # 2026-04-05: inversely correlated with power/heat output. Mode means:
-    # idle 52.9 (/100=5.3), heating 35.6 (/100=3.6), DHW 32.0 (/100=3.2).
-    # Higher COP at idle is physically expected (no lift, residual circulation).
-    50: {"name": "Reported COP",          "scale": 0.01, "unit": "",      "icon": "mdi:gauge",                "class": None},
-
+    # CONFIRMED: Cross-validated with HP installer page during DWH cycle.
+    # Previously Reported COP but unlikely to be provided via Cosy
+    50: {"name": "Suction",          "scale": 0.01, "unit": "bar",      "icon": "mdi:gauge",                "class": "pressure"},
+    # CONFIRMED: Cross-validated with HP installer page during DHW cycle
+    52: {"name": "Fan Suction",           "scale": 1, "unit": "Pa",    "icon": "mdi:gauge",                "class": "pressure"},
+    
     # --- Flow Rate ---
     # NAMED: Second sniffer matched to "Flow Rate" from HP installer page.
     # Value 1714. Units unclear — if ×0.01 = 17.14 l/min.