Thanks, I will test this when Im back on computer.

I tried calculating the values for the two point curve,

Outside temp -20 = 33c water

Outside temp   0c= 27c water

I got -0,3 offset and 270 gain? Anywhere near correct values?

Ok, floor heating with two curves added to the diagram.

Any comments about the diagram? 

I also could use some help with stopping the heatingpump when AI5 temp is over the setpoint

Thanks for the cleanup :)

The counter is there to see how long has the burner runned without error. That is just a test, I just realized that the I1 and I2 will reset the counter too soon and the reading on the counter is lost. So I will need to think it over a bit more.

The burner has it own control system and when the I2 on LOGO is activated, the burner has stopped already.

Hey again

I finally had the time to install this system and now i have been testing and tweaking it for few days and it's working pretty good actually!

I added some wirebreak/shortcut detection for the AI's, because I noticed that if I disconnect the AI4 ( Water TO the floor temp) sensor, it will give a -50c reading to the logo, which opens the 0-10V valve to 100% and let the tank temp water (45-95c) run directly to the floor and that would be really bad for my floors 

I also built a really ugly webserver to monitor the system.

My question is, is there a way to get a reading with deecimal points to the web server?

I'm reading some AM flags for the temperature, but I cant get proper reading out?

Second question:

Is there a way to adjust the reading that the PT100 gives? I think my sensors are giving bit low heat readings, is there a way to calibrate them?

Thanks again :)