Reading the temperature of the hot water tank
This one is not as easy as the export meter as the meter cupboard and the hot water tank are not in the same area as one another, so we had to purchase another Arduino. This time instead of a wifi shield I got the Ethernet shield – in reflection, not too wise a choice as the cat6 (yes overkill) cable that runs to the cupboard took a collective 5 hours to install.
For the temperature sensor we bought a linear thermistor (for those interested in replicating this, you can use one of these: http://cpc.farnell.com/microchip/mcp9700a-e-to/thermistor-linear-10mv-c-to-92/dp/SC10459)
The temperature sensor is then pushed in through the insulating hot water tank jacket with a dob of conducting gel to help the sensor get as good a reading as possible.
(The program loaded on the Arduino is in the next part)