Conrolling district heating with Arduino

When I was told that our old Danfoss controlbox (ECL 3310) for the distict heating was broken , I got a quote for
switching to a new one EUR 2000 - or if I was interested in one that could be remote controlled from my smartphone , approximately EUR 3000.
That made me look around for a cheaper solution, that I could build myself.
I therefore invested in an Arduino controller ( beginner set with various sensors , prototype board , etc. 250 kr . ) , Who has 6 analog
inputs / outputs and 12 digital inputs / outputs.
Additional Arduino EOR 10. (Available cheaper)
Ethernet connection shields for EUR 15.
6 pcs Temperature sensors EUR 18. ( Just to have a little extra ) .
3 pieces . 220 volt relays, EUR 25. paragraph to turn off the cirkulation punpe and control of valve ( up / down).
A whole lot of splices and some wire.
In everything under EUR 70, - for the parts that are in use for the controller.
Developed a small program to the Arduino to control the distict heating in same concept as a Danfoss gizmo .
Subsequently, temperature sensors put on the pipes in district heating device and a single temperature sensor is pulled outside and one inside a room in the house.
The relays are mounted via the old control box wall mounting , and temperature sensors are mounted and seems to show the correct temperatures stable.
The Arduinoen also runs smoothly, there were problems in the beginning, but that was because I used one old power supply I had lying around , it was
not quite stable , so a USB power supply for EUR 8, - for Arduinoen was purchased.
The program control is now on the same principle as Danfoss controller with respect to the valve opening in relation to the outside temperature
but there are also management on the radiator return temperature is above 30 degrees , so the valve is closed completely. The same happens if
indoor temperature of 21 degrees . If the indoor temperature drops below 15 degrees open valve with 10%.
All control parameters are stored in EEPROM , so they will be forgotten in case of a power failure or reset of the Arduino controller.
The Arduino logs temperatures and circulation pump and valve status once a minute on my server .

Temperatures the last 24 hours

Remote control of the distict heating

Spadestik from Arduino relays to the old vallmounting, so no cutting of existing wires.
Ethernet connection to my network, so it's available on the internet.
USB powersupply.
Temperatur sensors with ordinary 220V cables
So now I just need a nice box.