Propex HS2000 remote control from iPhone using SMS text messages
Having a gas heater in the van is a great addition, in fact, essential when staying away during cold winter nights. I have been using the Propex HS2000 heater for a couple of years now and am very pleased with it. While away it keeps the van nice and warm and is not very loud so I can sleep fine with it on.
As my van is also my daily vehicle it made sense to use the heater to get rid of any ice on cold and frosty mornings. I had previously fitted a Heatmiser household thermostat which would trigger the heater when the temperature was below a set level, it also has a timer feature. One problem with the Heatmiser is that the minimum temperature to trigger the heater is 5°C which is not really cold enough to justify using the heater, I only really wanted to use if there was a frost or snow. The other problem is that the timer comes on every day, this is not needed as I do not always use the van.
I started looking at how to use some kind of remote control which would operate a relay within the van and turn the heater on, the idea being that if I knew it was a cold frosty morning and I would be using the van then I could switch the heater on when I woke up. Many remote controls work up to 50 meters which may be fine in most circumstances, but there was one scenario I knew this would be no good and that's when I occasionally go and watch a football match on a cold winter's day. I wanted to be able to switch the heater on before I got back to the van so it's nice and toasty, the same if I'm out on a bike ride or a hike, or maybe just out and about when staying away. With this in mind, it made sense to be able to operate over the mobile phone network.
The device I opted for was a simple GSM Controller. These are readily available via the Internet, I bought the Quark-elec QK-G022 on eBay for £40. The controller has up to three relays and one RF switch. I have future plans to install a Raspberry Pi system within the van so will likely use one of the other relays for that. The controller needs a sim card which are freely available from companies like giffgaff where I bought mine. The only cost encountered are the texts sent back from the device but this is minimal.
The controller needs its own fused 12v supply, an earth and a positive fused feed for each device being used, this is connected to the central terminal of each relay. The other connection on the relay (open circuit) goes to the orange wire connection on the heater's thermostat control box, so basically overrides the switch when the relay is opened. The thermostat used to control the temperature cannot be remotely controlled but I don't think that's important as it's rarely changed anyway.
The QK-G022 has its own software available called GSM SMS Remote Control, but frankly it's not the prettiest of interfaces and all it is effectively doing is sending SMS messages to the device, however, you will need to use this software to first set up the device as you need to know the commands to send, the first thing to do is register the master control telephone number (your phone). Once set up, I installed another App from the App Store called My Commander which can be customised to use any SMS commands and looks and feels much better.
When a command is sent to the controller, it will automatically open/close the relay and then confirm back to your phone by SMS message, you could also set up another command to check the status of any relays, timers are also an option with this particular GMS Controller.
Now I can switch the heater on if I know I'll be using the van, I hope this will be of use to anybody else who wants this.