Winterizing heater

[Jeb1974]

Is the heater on a G23 with the 450 part of the closed cooling system (and not need to be winterized?) I will be gone for a couple weeks and the forecast right now is saying it'll be getting close to freezing so I'm going to drain water from the engine. I've heard that heaters are more susceptible to freezing and cracking and didn't want to risk it if it needs to be blown out as well.

[vision]

Heater has anti freeze, not raw water, on the Gs with the 450.

[Jeb1974]

Great. Thanks.

[Gbill]

Does the 2015 G21 with a 409 have fresh water going through the heater or does the heater have anti freeze? Thank you.

[Jeb1974]

The water flow diagram in the pcm book is the same for the 409 and 450 so I assume it also has antifreeze going through it.

[pinner99]

Yes the 409 heater also has antifreeze running through it.