The thermostat is used as any other one, but with the added facility of choosing the day or night temperature setting by means of a telephone. The remote control facility is operated via the telephone keypad, thus a DTMF type phone is required.

From audio signals sent down the line, the user receives a report back on how the thermostat is set. Switching is protected by a security code, set by the user, which is keyed into the telephone in a simple manner.

• separate settings for day and night temperature with LED indication
• relay output with LED indication: 5A / 240V AC (1200W)
• telephone pick-up after ± 3 or 8 rings
• report when the temperature has fallen below 37.4°F
• automatic hang-up if no code is received within 40 seconds
• possible security codes: from 000 to 999
• day temperature: from 57°F to 79°F
• night temperature setting: from 43°F to 64°F
• hysteresis (allowed temperature swing): 0.1°F
• local manual control
• supply voltage: 110V AC