docs(frisko): compressor and CWU parameters read on 2026-10-25

A one-off read-only FC3 of 4146-4166 and 4246-4247 between two gateway
polls. 4166 = 20 min explains the stage-2 switch seen in history and
4162 = 5 min the five-minute restart after a TmaxPc stop.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/frisko/rx910-se21.md

@@ -27,6 +27,8 @@ unless marked otherwise.
 | Outputs | 4112 CO, 4113 buffer, 4114 compressor (0/33/66/100), 4115 heater signal (heater not connected), 4116 circulation, 4117 ground, 4118 CWU | 0 or 100 |
 | Setpoints (F3) | 4131/4132 CO economy/comfort (5–35), 4143/4144 CWU economy/comfort (5–70) | whole °C |
 | Protection | 4158 TmaxPc = 52 °C, 4149 TmaxCWU = 55, 4148 HistCWU = 5, 4146 PriorCWU = 1, 4147 heater signal delay = 20 | read 2026-10-23 |
+| Compressor | 4166 zwlZSt(II) = 20 min (stage 2 delay, matches history), 4165 zwlZSt(..) = 10 (likely stage 3, never seen), 4162 t_wylSpr = 5 min (minimum off, matches the 18:20 stop / 18:25 restart), 4160 t_zwlZalSpr = 20, 4161 t_zwlWylPdz = 20, 4163 t_minSpr = 160, 4164 t_maxSpr = 230 (units unknown); 4157 TminDz = −3, 4159 ∆TmaxDz = 10 | FC3 read 2026-10-25 |
+| CWU extras | 4150 TpodbCWU = 5, 4151 t_podbCWU = 15, disinfection 4152–4154 = 7 days / 60 °C / 60 min (off: 4145 = 0), 4155/4156 t_zal/wylCCW = 2/2; 4246, 4247 read garbage (not on this firmware) | FC3 read 2026-10-25 |
 
 Unknown: 4119 `WyCHL` reads −14308. Vendor-app findings, all unverified: [app-knowledge.md](app-knowledge.md).