It’s advertised as “No C Wire needed” but… (Heat only)

[Mosesmac]

I have a 2 wire (red/white), heat only thermostat that I was looking to replace with the Nest 3rd Generation Learning Thermostat. I know it says that the C wire is NOT required. However, from what I have seen and read everywhere is that the system will not hold a charge without the C wire. At my furnace I see the Red and White wires connected and there are other wires that are not being used at the furnace end as well as at the thermostat. 

My question is, can I connect any of these wires not in use at the C terminal at the furnace and then connect it at the C terminal of the Nest for this issue? Or is there no need to?

I’m assuming this wasn’t an issue for my last thermostat as it was battery operated.

Thank you for your assistance. 

[FititFelix]

Google sells and so does Amazon the Google Newt Power Connector - C Wire Adapter. I did this on my furnace and it works perfectly. 
https://a.co/d/908nG2l 

[GBD · Accepted solution]

You certainly can connect any spare wire that is contained in the cable to C in both the furnace and thermostat. 

[Mosesmac]

Thank you GBD I did that and all works well thank you again.