semiatic

What the light, symbol or code on your thermostat means: Nest, Hive, Honeywell, ecobee, tado, Wiser and Sensi

71 documented states on 7 makers’ thermostats, each from the maker’s own help site, covering 84 code numbers. On a Nest, E73 means the heating and cooling system has stopped powering the thermostat; N72 means one wire is getting less power than expected, and Google says you can often dismiss it. On Hive the lights that matter are on the receiver by the boiler: solid red there means it has lost the thermostat. A blinking “Cool On” on a Honeywell is a five-minute compressor delay, not a fault. So pick the maker and what you see, or type the code.

Find it by what you see

71 states.

Codes: type the code as it appears (E73, N72, W5, H1, 181, E0). A Nest code starting with E also brings up the general E-code page, since every E code is critical. Where a maker names a light but not its colour, it matches any colour you pick.

The same symbol, different meanings

Symbols that more than one maker draws, each for its own thing. A snowflake or flame on a boiler’s own panel is different again, and has its own page.

SymbolWhat it means, by maker
snowflake
flame

By maker

What these pages cannot do

Left out, and why

A maker gets pages when its own help site documents at least 5 thermostat states and we could read them. All 7 makers above did. These were not used:

Sources

Each maker’s own help pages only, read on the date shown.

Google Nest thermostat

Hive thermostat and receiver

Honeywell Home thermostat

ecobee smart thermostat

tado° smart thermostat

Drayton Wiser radiator thermostat

Sensi smart thermostat