Safety boundaries for error D90
Disconnect power when instructed, control water where relevant, and stop before disassembly or electrical measurement. Specific stop conditions: The dryer or vent is unusually hot; D90 returns after professional vent cleaning.
Safe sequence
- 1Stop and unplug the dryer.
- 2Clean the lint filter and inspect only accessible duct sections.
- 3Use a professional vent-cleaning service for the home exhaust system.
Stop and get qualified help when
- The dryer or vent is unusually hot
- D90 returns after professional vent cleaning