Engine not fully heating up

[Davidmorris]

The gauge is controlled by a coolant temp sensor that is sat in the water jacket. The thermostats are there to maintain a constant temperature one or both failed/failing can cause heating issues .

[NZDubNurd]

Have a look to see if you have the DSG stat too - there is a skoda forum article somewhere. It's inline, in a hose and shouldn't be confused for a one way valve some cars have. They look similar, but the stat one has a metal clip in it.

Either one not stopping the flow properly, means coolant can go to the radiator, when it should be circulating inside the block only (mostly).

[DeanWhit]

Finally sorted. It was the DSG stat.