r/Generac_Generators

Edit: thank you everyone! I'm going to pass on this

I'm looking at buying an older Generac Guardian and wanted some opinions on what it's actually worth.

Details:

- Model: Generac Guardian 0043901

- Approximately 2003

- 15kW continuous / 16kW peak

- 992cc GT-990 V-twin engine

- Currently running on natural gas

- Unknown total hours, no hour meter

- Approximately 18–20 days of runtime over the past 10 years, plus weekly exercise cycles

- Uses roughly half a quart of oil every 48 running hours

- Some oil residue in the enclosure, possibly from messy oil changes rather than a leak

- Some rust along the bottom of the enclosure

- Reportedly maintained regularly and runs reliably

The seller is upgrading to a larger unit and will let me see it running before removal.

I'm planning to convert it to propane and install it myself with permits.

Main question: Is $600 a fair price for a 23-year-old standby generator in this condition?

I've seen older Generacs sell for $300–$500, but I'm curious what others have actually paid or sold similar units for.

Would you pay $600, negotiate closer to $400, or pass entirely?

One additional question: Has anyone used one of these older Generacs with an inverter/charger like the EG4 GridBOSS/FlexBOSS? Any issues with THD or voltage/frequency stability?

thank y'all for any help. I'm new to generators and trying to learn

I live in Pensacola and am looking at an extended period of power outage in the wake of Hurricane Isaias. I have a whole-house generator and until 7pm last night, 400 gallons of LP gas. We had used about 5% when I checked earlier today.

We are leaving on vacation for a week. Would it be crazy to leave the generator running while we’re gone? It’s an older Gen but has had regular service and we have a brand new transfer switch.

My gut tells me to shut it down, but there’s a fridge full of food.

Edit: planning to shut it down when we leave. We might actually have power back before that, but if not we’ll drop some stuff off at my son’s house an hour from here. We’ll be taking some with us, as we’re going camping. Camper has a fridge.

Want to get opinions on this: I just discovered the slab under my 24kW Guardian has tilted. It is 1 and 5/8ths inches out of level on the long dimension and 1 inch on the short dimension. I know the spec is no more than .5 inches out of level in any direction. So I guess it has to be uninstalled and the slab fixed? Thanks!

The sale ends tomorrow and there is no delivery charge. It looks like a good deal to me.

The hurricane is barreling down on us. Once the generator starts running,

1. How do I turn it off for the rest period?

2. How many hours should I let it run before a rest period?

3. How long do I let it rest?

Extra question: will it shut itself down if it gets too hot or oil gets too low?

I have the Mobile Link app.

It's on a every 6 month service plan and the oil was changed a less than a month ago.

Thanks.

Had a customer whose Generac kept getting mice in it. Chewed wiring twice, cost him a service call each time. We'd sealed around the conduit where it comes up through the pad with duct seal and they just dug around it. Spray foam didn't last either, they chewed right through.

What ended up working was a pour-in sealant Polywater makes called InstaGrout. It's meant for utility transformer pads but it's the same problem. You mix the two parts, pour it in the opening, and it levels out then expands and fills the gap around the conduit. Sets up hard. If you need to add a conduit later you can just drill through it.

Haven't had a mouse in that unit since. The small kit was more than enough for a residential stub-up.
Just don't block any of the vents, only the opening at the pad.

Full disclosure, I work for a distributor that carries it, so take that for what it's worth. Mostly curious what everyone else is using. Anyone found something that actually holds up?