Fluid type in heater system

[lunatic]

I am having my heater motor serviced today and the old heater fluid will be drained out and replaced. See image of my existing fluid.

I have heard that you need special glycol in the heater system, not just automotive glycol. Is that correct? What is suggested is Propylene Glycol (USP food grade).

Does anyone also know the fluid capacity in litres of the heater system?

Any advice would be appreciated.

Ian

[lunatic]

Image of fluid attached now!

Ian