Zafira owners might be interested ...

[henryd]

So what's the actual issue with these? Material used for the resistor combusting? 

My guess is that the bearings in the fan motors have been seizing (possibly made worse by water ingress through the scuttle). A partially seized fan will draw more current than it should but pass less air over the resistors.

More current and less airflow results in an overheating resistor pack. VX probably fitted one or more solder links on the base of the resistor pack to act as thermal fuses (the solder used in sprinkler heads melts at 70 degC so VX could have chosen a low melting point solder)

The final piece of the jigsaw is either a DIY fix to link out the thermal fuses (or an ebay replacement without fuses) to turn the resistor pack into a glow plug.

Over heating of the fan motor also easily caused by a blocked pollen/cabin filter

[STEMO]

It's a shame, really. Zafira was/is the cheapest and simplest people carrier/van around. Just about everyone has had one at some point. I never had any bother with mine and I certainly gave it some grief.

[BazaJT]

In fairness the number of vehicles of different makes being recalled-albeit maybe not for fire causing issues-is quite frightening