I have this window Contact now been amply 8 weeks. So much in advance: Its main task envisaged fulfills the following conditions: The via FHEM controlled down-regulation of the radiator thermostat with the window open. But otherwise the part makes with firmware version 2.2 only problems. - The battery status is not transmitted properly regularly to the head office. - Yesterday, the contact after opening the window switched to continuous transmission and therefore the batteries that are supposed to keep empty for two years sucked. Apparently one of many errors in the firmware. - Every now and then fails the radio contact with the control panel, even though the equipment locations (6m distance) does not change. - It should be added that this is already my second window contact HomeMatic. The first I had to change, because it did not work. Meanwhile, users have reported on the forum that new deliveries are equipped with firmware 2.4. This gives us hope that the manufacturer is working on problems. However, it is available as a user of a previous version as a beta tester in the rain. Even if the window contact HomeMatic with just under 30 euros, compared to other manufacturers appears rather favorable, one can expect that the device is working properly. The confidence in this product is supported only by the fact that it fulfills its main task (yet). But I am seriously if I change not to another product line (eg EnOcean).
Supplement on 03.02.2015:
I have the window contact now for about 10 months in operation. The initial problems have subsided. The unit performs its service since reliable without further problems. Meanwhile, I have included several window contacts, but now put on the optical version: HomeMatic wireless door / window contact optical HM-Sec-Sco, 130297 They work right away, are with me but only for a few weeks in operation.
Besides the type of trip (magnetic / optical), there is an important difference:
When the magnetic contact only the housing is screwed or glued to the window / door. The electronics can be removed, if you fancy a more frequent need to press the teach button down for a configuration change.
In the optical touch the electronics are installed in the housing, so you have to go-out of configuration changes in order to achieve the teach. However, the optical window contact has a design advantage: It is supplied with an additional brown cover, so that one choice of white or brown can install.