This project was started to control my Central Heating system remotely. There are 2 options to control the heating:

• Normal (using configured profile/schedule)
• Tele program (pre-configured profile: 17 degrees centigrade (32F)

Goal
Control central heating and set it to a lower temperature when ‘away’.

How
Get a Marmitek UM7206 Universal receiver. When it receives an ON message (for example) D5, it will close a loop.

This loop happens to be connected to the ‘TELE’ connector of the Honeywell Chronotherm Vision TH8100 thermostat. When this ‘TELE’ connector is closed, it will jump to a pre-defined program (17 degrees centigrade in this case).

Architecture

Ideal
Full control over my thermostat (central heating) over IP.

Cost

• Honeywell Chronotherm Vision TH8100 (€ 175)
• Marmitek UM-7206 (€ 50)

Done

• Replaced 2 wire cable from original thermostat to central heating by 8-wire CAT 5 cable (only 4 required)
• Mount Honeywell thermostat and make sure it’s working
• Connect 2 remaining wires to the ‘TELE’ connector on the thermostat
• Connect the SAME 2 wires to the Marmitek UM-7206
• Set the house- and device-code on the Marmitek UM-7206 (example: D5)
• Create a device in HomeSeer to control the UM-7206:
• When an X10 signal is received D5-ON or OFF (UM-7206 device code) then the ‘TELE’ port will be switched, therefore controlling the thermostat.