Temp Gauge Reading Low

Driving from cold today I noticed the temp gauge took a lot longer than usual before it started to rise. Equally, the heater also took longer to reach the point of producing hot air than it normally would. When the gauge reading did rise it never reached the normal point just above the halfway line.



HG has recently been replaced and I no sign of any loss of coolant........



My first thoughts are a faulty sensors (ECU or Gauge) or a possible air lock?



There doesn't appear to be a great deal on searches just carried but I'd bet a few have some knowledge/experience of this........



Feedback appreciated

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