What model do you have? What year?
The fact that an Espar furnace has worked "flawlessly for 6 years" and no longer works, usually means that it is in dire need of servicing, which based on my experience with a D7 and D5L should occur every couple of years.
Could be glow plug, fuel dosing pump, blower motor failing to reach needed rpm, control box/wiring failures, inadequate DC voltage, etc, etc, etc.
Time to find a local service provider.