RE: Honeywell CMT927 Wireless thermostat

["Neil Ball" <neilball@xxxxxxxxxxxxxxx>]

The CM Zone & Hometronic all use a proprietary Honeywell RF
protocol
operating at 868MHz so I doubt you will find anything that can sniff,
record
& replicate the signal.



I'm not too familiar with the CMT927 (it's the new replacement for the
CM67RF) but assuming it has the same basic commands then you may be able to
hack into the unit & hardwire a remote relay controlled from your PC.
By
having the relay replicate the "temp up" button you could have it
simulate a
number of presses to give you a reasonable heating setpoint. Might be best
to buy a cheap CM67RF to modify from Ebay if you can find one and register
it to the HC60NG - the HC60NG can have upto 4 devices registered to it.
That
way your CMT927 remains untouched for normal daily operation and it
therefore does not matter if the 2nd unit is mangled during the upgrade as
you can keep it out of sight close to your PC.



Having said all that it might be easier to just have a timer relay you can
switch via the net and wired in parallel with your HC60NG so that you get a
timed heating override when operated although this has no room temperature
control.



Neil B.





_____

From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of Ho
Yin Ng
Sent: 08 January 2008 14:56
To: ukha_d
Subject: [ukha_d] Honeywell CMT927 Wireless thermostat



I have a Honeywell CMT927 wireless thermostat.

It obviously sends a wireless signal to the receiver to turn on the
boiler. Does anyone know how it sends the signal? And is there anyway
to copy this signal? Then get something that can replicate it and be
controlled via my computer?

Then I could turn on the heating remotely i.e. 30mins before I come
home on the train to have a shower! SWMBO would love me ... and of
course you for it.

Ho Yin



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