Slow warm up

[realh]

I've got the normally aspirated 1.6 petrol model and it's been a bit slow to warm up ever since I've had it, which hasn't been much of a problem, but on very cold days the heater is too ineffective on my typical short journeys. I haven't found any similar reports on Google, but when I changed "DS3" to "Mini" (because they use the same engines AFAIK) it seemed like quite a common problem. Is it reasonably cheap to fix, or is the thermostat buried deep somewhere?

[Owd git]

The only symptom of the problem we currently have is that the heater hardly works any more

[DazzerLancs]

Mine is the same, during a software update the technician told me that my thermostat housing will most probably require replacing at what I’m told will cost about £400 at citroen or about £300 at an independent garage, not sure if just the thermostat can be changed but my main concern is will this affect the running as mine has a slightly “lumpy” tickover