understand warranty, understand sound level, understand homeowner’s responsibility as far as routine regular maintenance...

Is this 22 kW size?

Gasoline or propane or natural gas powered?

You will need to read and understand all of the installation instructions, including in particular distances to combustibles, including fences, trees, etc. There is an exhaust risk and a fire risk.

You will need an automatic transfer box that disconnects your house from the power company when the generator is running, and which triggers the generator to run when the public power fails.

You will have to run gas lines. You will have to run electrical power and control cables while conforming to NFPA 70 (National Electrical Code).

You may want a relay box and added breaker box next to your existing breaker box(es) that contains a continuous running relay that can drop out loads you don't want running when the public power is off and the generator is on. Note that the generator should not be loaded beyond 80% of its rated power.

You may want to purchase a generator that self starts each week and runs for some period to keep itself in good shape and demonstrate functionality.

I have had a 22 KW generac for a few years now. First, it is great for the short term power outages we have ( anywhere from a few hours to a day or so). It can run most everything in our house, including AC and heat, so you don't have to rent a hotel if the weather is bad. No more dragging a generator out of a shed and running extension cords to keep freezer and refrigerators going. I tell people that the cost benefit ratio, at least for us, is crazy, since we could rent a hotel room and replace everything in the freezer and fridge probably 20 times before we approached the cost of the generac, transfer box, and installation, but it is awfully convenient to say in the middle of a storm - power's out, then keep on doing what you would otherwise be doing. It is louder than an outside AC unit, but no where near as loud as most portable generators. The regular maintenance is not bad, change the oil, every 2 years ( which reminds me . . . ) and you can buy a kit on Amazon that includes the air filter and oil filter. Overall, very happy with the purchase, and sorry I did not do it sooner. While Kaseki makes several good points, if it is the 22kw, I would think you would get it professionally installed, and they will put in the transfer box, and relay box, and consult with you about what circuits can be powered. It has an automatic cylce to start and run - and you can set it up to do it every week or every two weeks.

Thanks for this! We are having it professionally installed and maintained. Yours only runs for a day? The person I spoke with said it was fine for at least 200 hours straight. Ours is going to be run off the natural gas line

Normally, power is back on in a day or so. The manual says you need to change the oil and filter every 200 hours , so I don't think it is designed to run for 10 days non stop. BTW, we have natural gas as well, so it is not that it would run out of fuel, it is just that it is designed as a standby. I thought the manual said to turn if off and let it cool if it runs for more than a day, but I just checked the online version of the manual and don't see that, so I may be mistaken.

Thank you!

A quality generator should be designed to operate for extended periods, but not without maintenance. 200 hrs on an automobile corresponds to 8000 - 12000 miles. Also, the lifetime of modern synthetic oils is quite long; it is other factors such as acids buildup from blowby that drive engine oil replacement. Filter change is related to dust ingestion so some areas of the world will have more stressful conditions than others. The longest power failure here since the generator was installed has been about 20 hours. Otherwise, the condition of running 20 minutes once per week is more contaminating over 200 hours than running 200 hours continuously.

I have changed the plugs, oil, and filters on my generator a few times. (Millbank 20 kW / Briggs & Stratton engine) My engine oil change requirements are first 5 hrs, every 100 hrs afterwards or annually. My third change was at 282 hours, and I intend to change the oil, etc., again this summer.

Pay attention to the lifespan of the (usually lead acid) battery. Otherwise you may find you have to change it in the middle of a snow storm or some other more than normally inconvenient time.

Be warned that these suckers are NOISY! Even in "Quiet Test" mode. Our neighbor's kicks in a 11.00am every Saturday morning to test - the whole neighborhood can hear it. If it kicks in at 2.00am in the morning, he'll have a riot on his hands!

We have had a 22kw Generac generator for about 6 years now, and it is one of the best purchases we ever made. Power in our area goes out at least two or three times a year, often for more than a day. The Generac has worked seamlessly every time.

When we had a six day electrical outage, the yellow warning light appeared on the Generac after about three days (but Generac was still working fine). Our service company came out and changed the oil, although they said it would probably have worked fine for another few days without the oil change. During other outages for two or three days, the Generac has worked fine without needing service. It makes me feel a little guilty when we're enjoying a well heated (or well air conditioned) home, lights, hot meals and able to do laundry in the middle of a power outage.

The key is to get the Generac serviced every year, and have it exercise itself once per week. Keeping it in working order will avoid the vast majority of problems that others have with generators.