The car (engine) either takes a long time to reach temp (30 mins+under constant load e.g. an a cruise on the motorway), and when it does under light use the temp goes down, or it doesn't reach temp at all. The heating therefore never gets hot/warm, especially the last few cold days.  

 

Happens in all weather not just the cold. The car is never used for short journeys.

 

Any ideas? Thermostat or something else, the car runs fine otherwise. 

 

Thanks in advance for any info.

Sounds like classic thermostat stuck open failure.

 

On 14/12/2018 at 14:37, LB123 said:

Sounds like classic thermostat stuck open failure.

 

Seconded re thermostat