I recently replaced my home heating controls with the Hive system from British Gas as my old system had developed a fault with the receiver not switching on the boiler intermittently due to a faulty relay contact. The Hive system worked great for about 3 months until the other day when I noticed it was cold and the heating wasn’t working.
Thinking there was a fault with the boiler I had a look but everything was OK. The Hive receiver was showing the green light indicating that everything was OK. However everything was not OK. The hive thermostat just showed “NO SIGNAL” and no amount of resetting both the thermostat nor receiver would make it work. I decided to move the thermostat next to the boiler and hey presto! It worked. Took it back downstairs and no signal again. What was going on?
I tried the batteries but this didn’t help. At a loss and unable to call British Gas which was the only solution in the “help” section of the manual as it was late at night I did a bit of investigating. It turns out the thermostat communicates with the other modules of the system via zigbee system at 2.45Ghz. Now this band is occupied with a mariad of wireless devices (wifi, bluetooth, microwaves, cordless phones to name a few) so I got out my trusty scanner I made from an Arduino which showed a very high level of interference between wifi channels 3 and 9 which 2.45Ghz is about half way between channels 8 and 9.
I turned off several things around the home but that strange signal was still there. I fired up wifi analyzer app on my phone and saw a wifi signal from a Virgin Media router that was stronger than mine. Turned out that the neighbour in the back to back terrace I live in had got a new internet provider and it was swamping out my hive’s signals. My own wifi router was adjacent to hers so I changed my router’s channel to 1 from 6. This fixed the problem and the thermostat works. It briefly shows “connecting” when operating it which it didn’t do before but at least the heating works now.
So, the neighbour’s wifi router is still causing a problem. Aside from going round there and asking if she can reposition it there isn’t much else I can do. There isn’t any facility to change the frequency the hive operates on.
Just goes to show how much wireless devices can interfere with each other. If you live in an area with a lot of wifi networks and the boiler is some distance away from your thermostat the hive system may not be for you. As for me Ill see how it goes and possibly change it for something else. My old one allowed you to choose from 4 different frequencies should interference on one of them occur.
On a related note, a “leaky” microwave oven can be a very effective 2.45GHz wireless jammer, too.
The oven magnetron is even more powerful than 1000 wireless routers combined, and it covers the entire 2.45GHz band, with plenty of excess bandwidth either way.
Even a slightly warped or bent door can cause enough microwave leakage to jam wireless devices in a several meter radius.
NB, defeating the interlock and running at full power with the door open increases the effective jamming range to hundreds of meters, if not more, but it also cooks YOU, so Don’t Try This At Home.
That could be another use for my wireless scanner – it could be used for a microwave leakage detector.