Do I need a phone line for my temperature sensor SK627?

There are two ways to use the temperature sensor SK627.

First as a standalone alarm. In this case, the temperature sensor SK627 doesn't need a telephone line. When triggered, it will sound the integrated alarm locally.

Second as a wireless sensor to trigger a dialer to call you via your home phone line.

In this case you need to pair the temperature sensor SK627 with a dialer, sold separately, such as SK618, or in the kit SK633 & SK634, etc. These dialers need a telephone line that uses PSTN (sometimes called POTS) technology, not the VoIP technology. The simple way to check if your phone line is PSTN or VoIP is to ask whether you can send fax through your phone line. If yes, then your phone line is PSTN, and you can use our dialer to make calls to any phone number in the world.