Not sure about the circulation, but I know my bus (Vanagon, I'm going to stop pointing this out) won't warm up while idling.  I have left it running for a while before, but in my experience, it doesn't really get warm until one drives the vehicle.  This is a common thread among all the Vanagons I have owned.
Efficient little engines aren't they.

Dave B.

-----Original Message-----
From: Jeff Palmer <w.jeff.palmer@ICLOUD.COM>
To: vanagon <vanagon@GERRY.VANAGON.COM>
Sent: Tue, Jan 2, 2018 8:54 pm
Subject: Re: It's cold out there

Also you’ll get more heat at speed. Does the coolant even circulate at idle?
Jeff

Sent from my iPhone

> On Jan 2, 2018, at 7:52 PM, Jeff Palmer <w.jeff.palmer@icloud.com> wrote:
> 
> Back when I drove my 85 year-round I would slide cardboard under the bra to cover the upper and lower grills. Not sure if there’s a functional difference between the two. It helped a ton. Also used an oil pan heater, battery blanket, and lighter weight (or synthetic) oil. 
> 
> Jeff
> Balmy -15C today
> 
> Sent from my iPhone
> 
>> On Jan 2, 2018, at 6:39 PM, OlRivrRat <OlRivrRat@COMCAST.NET> wrote:
>> 
>>       It may just be that You have the Coolest Version of the "Standard" Thermostats in there ~
>> 
>> I'm not actually aware of what is available for that Eng' ~
>> 
>> 
>>> On 2 Jan , 2018, at 12:11 PM, ddbjorkman@verizon.net wrote:
>>> 
>>> Ford battery died and the Bus (Vanagon) has been put into extra service.  Always starts right up, hope I didn't put a whammy on myself with that.  Well, it's into the single and low double digits here in New England and I have noticed the Bus has a hard time maintaining heat to the interior.  My temp gauge sits on the lower edge of the red light.  It takes the normal 5 + minutes driving to warm up enough to move the gauge far enough off bottom to turn the heat on at all.   I am considering constructing some sort of bra to go over the upper grille to decrease air flow over the radiator.  First I thought  I might post this question.  Is this normal in the frigid cold?  Have others experienced this?  Could it be a malfunctioning thermostat?  Does someone make said bra/cover?  I await your reply.
>>> 
>>> Dave B.