What has happened to my car heating- electrics?

[tracyk]

My Renault Laguna - about 5 years old - has a prob with its heating. I can turn it up to 25 and it is only just warm air coming out the vents. Normally I would be melting with this.
Not sure if it is a co-incidence but my clock and temp digital guage is now showing the temp in degrees farinheight. Does the heating think 24 is now farenheiht too?

Have you checked there is water in your car. If the water needs filling up you won't get any heat out of the heaters.

Well, it does say my screenwash is low - but would it alert me to the radiator water - or wherever it is, being low?