Originally Posted by bloke
Problem is i can get the the temp to stay at the set "sv" value 65 degrees Celsius in my case. It alway gets higher and higher.
Do you have circulation in your HLT? If not you will likely overshoot the set point. If you have a pump try to circulate the water in the HLT. If not, stir with a long spoon as it is getting close to the set point. Water likes to settle in layers of different temperature, "stratification". Some brewers put a stirrer motor on their HLT to break up the temperature layers.