I have a Myson Kickspace 600, the fans stays on constantly whatever the temperature. There is only one part it can be - Low Limit Thermostat, problem is I can't source this part anywhere. Any ideas for an alternative?
It looks like they are have the part at phc, click here. for info.
I just wondered if you had checked that the summer / winter switch is set to the sun position and not the snowflake position? In the snowflake position the low limit thermostat is by-passed and the fan will run constantly. [In the sun position it detects when the hot water is not flowing and turns off the fan.]
If the summer / winter switch was broken it could also create the same problem, as the two items are wired in parallel.