Place a Nest Protect near to the CH Boiler and if Nest Protect detects carbon monoxide, send a command to EvoHome to turn off the boiler.
This Trigger fires every time the Nest Protect you specify detects dangerous carbon monoxide levels.
This Action will enable a quick action at one of your locations. This can either be permanent or for a number of days/hours.
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Nest Protect and Honeywell evohome