tado Smart Radiator Thermostat E1 calibration error

What Does Error E1 Mean?

tado defines Smart Radiator Thermostat E1 as calibration failure because the closed valve position was not detected. The support path focuses on secure mounting, the correct adapter, adequate batteries, and a valve pin that moves and returns properly. E2 and E4 are different calibration outcomes and should not be merged into E1. Applies to: tado Smart Radiator Thermostat This page follows tado's E1, E2, and E4 radiator-thermostat support article. Hardware generation, mounting bracket, adapter, and valve body vary, so use the instructions for the exact tado device. Owner-safe checks: Use the exact tado mounting guide, fit compatible fresh batteries, confirm the correct adapter and secure head, and never dismantle the water valve. Qualified technician: Leaking, bent, seized, damaged, or uncertain radiator valves, pressurised components, and recurring calibration after correct mounting need heating or tado support.