Thanks JohnMo
I will give that a go. I have noticed when the heating clicks on they appear to go into calibration mode sometimes (fast flashing light for a minute or 2) before going to a slower flashing light which means they are adjusting and then settling to a solid light.
I am not sure why they would be going into calibration mode so often. And maybe if the loop is already warm or the heat request turns off to soon this is why they are not calibrating correctly.