Have a Weil McClain CGa-4 gas boiler 105,000BTU input. Would like to have a backup generator. Because of the electronic spark ignition I assume it would be preferable to have a inverter generator. [B]What size generator would I need?[/B] I've looked for hours online for power requirements without satisfaction. Sticker on the side of the unit says it uses "less than 12amps". Does that mean 6, 8, 10, 11.5amp? (And yes I know Volts X Amps=Watts.) Wiring is enclosed in metal conduit, so I really can't use a clamp meter. I'm posting here hoping someone would know the exact power (wattage) of the unit.

This is a gas furnace Luxaire TG8S080812MP11A about 10 years old. For the last three mornings this furnace has been blowing cold after pulling temp up just a couple of degrees. When I cut pwr to unit and wait a minute, she behaves normally and will be good for the rest of the day maintaining 68F, but it's that temp pull up from an overnight 63 to just 68 (930pm--0646am) that messes something up. What do I do to fix?