[dave_r]

...it'll be fine to run it briefly, if you want to first make sure the engine is functioning ok, before putting out the money for a new thermostat...

 

[dave_r]

Oh yeah, just remembered, if you still have the old one, even if it's not working, you could hack the thermostat so that it just stays open all the time. It's not ideal, but it does help with a bunch of problems related to not having a thermostat installed at all.