First of all, I apologise in the case that this question has been asked before (I'm sure it has been countless times) but I'm unable to find a thread on it.

I purchased a 2012 Focus Mk3 1.6 tdci yesterday evening and today I discovered an issue with it, when I got into the car this morning to leave it heat up before work, I turned the heating on but nothing happened, no level or setting would work. I resorted to wiping the windscreen with a cloth and driving to work which is about a half hour drive, after about 20 minutes or so the heating magically came on, the temp gauge on the dash was showing just under half way at this point (I thought maybe this had something to do with it). A side note to this is that I pulled in to a drive through coffee place just after this, the temp gauge on the dash slowly dropped to zero again while the care was idling as I waited for my coffee, it crept back up again as I started driving.

The same occurred leaving work this evening, no heating for about 15/20 minutes of my drive, after I pulled in to get diesel near home, the heating refused to work upon start up once again. I left it on to see if it would come back on, and it turned back on as I pulled into my drive (about 5 minutes after I stopped for diesel).

I understand that blown fuses or AC compressor clutch failures could be a cause, I'm just looking for anyones thoughts of what could be the most likely culprit for my situation, any help at all is appreciated.

Thank you!

17 hours ago, MK3bobi said:

turned the heating on but nothing happened, no level or setting would work.

Hi Rob,

Do you mean that literally nothing would work (fan, etc) or just no heat?

I used to be a big diesel fan, the downside was they can take ages to warm up (due to their thermal efficiency), so the heating is likewise, unless they have a supplementary electrical system.

In very cold weather, I used to shiver for the first 20 minutes or so of my commute.

Fuse etc is unlikely - if it works eventually. Faulty thermostat is a possibility if its really slow to warm up.

One point - check your coolant level. I had an issue with no heating on one car and found the heater matrix had split.

There are lots of threads on here on similar topics, as you suspect, but finding them is another matter! Example:

https://www.fordownersclub.com/forums/topic/99643-temperature-problem-with-focus-diesel/

Thank you Eric!

Yeah I had a thrall through 30 pages of results in this forum and was unable to find anything so I resorted to posting, I will have a look at that link, thank you.

Unfortunately, I mean nothing at all would work, I turned the switch to 1,2,3 & 4 and nothing came on, no lights and no air being blown out anywhere. This was the same for cold air and hot air options.

I heard that the coolant could be an issue but the level seems to be fine.

If you've got manual dials with 1234 then that should do exactly what you ask of it. There's nothing automatic about that system.

It is strange that it seems to work after a set period of time but I think this will be a fault within the HVAC panel. The panels are cheap to buy used on eBay so I'd just try a new one of those tbh.

Low coolant would stop the heater heating, but won't affect the fan speed. And as already said, fuses can't be intermittent, they're either blown or not.

24 minutes ago, TomsFocus said:

If you've got manual dials with 1234 then that should do exactly what you ask of it. There's nothing automatic about that system.

It is strange that it seems to work after a set period of time but I think this will be a fault within the HVAC panel. The panels are cheap to buy used on eBay so I'd just try a new one of those tbh.

Low coolant would stop the heater heating, but won't affect the fan speed. And as already said, fuses can't be intermittent, they're either blown or not.

Thanks Tom, I will try a new panel, I fear maybe an electrical issue now after today, as it’s now not even working intermittently, I drove the car for a total of 2 hours today and it didn’t come on at all. So I’m thinking that it working intermittently was that it was slowly fading and now it is completely gone.