I have run my sump, furnace and one refrigerator off my 8k portable genny. Laminated instructions on the generator on the steps to follow to get it all set up.
We have a manual start 20kw lp fueled generator in the garage, dedicated exhaust up thru the roof. Float charger on the starter battery. Manual transfer switch to engage power to the house. We've had it since 1999, and no trouble at all with it. Consider using synthetic oil in the engine, it is well worth the extra cost.