My 20kw air cooled generac is only a few weeks old and I just viewed a weekly exercise mode recently and I didnt like what I saw for a brand new unit. During the exercise mode the engine runs and a lower rpm than when the unit is online supplying power to your house. The engine was running very rough and there was a large natural gas smell from the exhaust. After researching this online it appears that this model 5875 has this problem with many others. The second cylinder does not fire during the exercise run so that the engine runs at a lower speed and is quieter. So the engine runs very rough and it pumps out the unburned natural gas from cylinder number 2 into the exhaust and out to the atmosphere. I would much rather have a smooth running engine running efficiently than a quiet engine during the test mode. Beware if your shopping, like I was three weeks ago.

We recently purchased and installed a Generac 18-20KW Stand-by generator. It uses natural gas. We had upgraded our electric service to 200 amp and installed the automatic transfer switch as part of the upgrade. The day came for installation of the generator and all went smooth. The unit was tested and worked as anticipated. Not more than a few days later our power went out and just like clock-work the unit kicked on within seconds and ran flawlessly restoring power very quickly to the whole house. We are very pleased with this unit and we now have peace of mind knowing that when power is disrupted by windstorms, ice storms or other reasons, our critical systems will continue to work keeping our food refrigerated/frozen, our furnace running and the lights on. More than enough power to run the whole house. We could not be more pleased with our system.

We have springs under our basement floor and a sump pump needs to run at least every hour or our basement starts filling with water. A generator is a necessity. The one we used to have needed to be started manually. The new generac is automatic, the power goes off and in a few seconds we have power again. Great in the middle of a cold night or when we are gone. True peace of mind.

We had a 2400+ sq ft home built in 2010. During the design phase I told the builder I wanted a whole house generator. My only requirements were that I wanted to be able to turn on every light in the house, run two refrigerators, a freezer, the oven, the A/C, and any other appliance we had in the house in the event of a utility failure. The electrician spec'd a Generac 20KW natural gas unit that would be converted to use our LP gas. This unit fires up every Wednesday at 09:00 AM going through its self-test. I perform the the routine maintenance on it myself (oil changes, air filter, spark plugs). Maintenance is a simple as a typical lawn mower tune up; it couldn't be easier. Although we have not had any extended power outages to really test the unit, I feel quite confident it can handle anything we need from it. My wife and I are both retired and don't need any surprises at this stage in our life; our Generac 20KW generator gives us a piece of mind neither of us had in previous homes.

Have had generator for 3 1/2 years...needed it a few times for short durations...NOW Hurricane Matthew....generator has been running for 5 days....house is nice and comfortable.....turn it off everyday for a few hours to give it a 'rest' , check oil etc....no problems keeps on going....

I wish I had purchased my generator years ago! We had 2 hurricanes in October of last year, one of which we were without power for 6 days. My generator was a life saver! It has already paid for itself with that first storm! I would recommend Generac to everybody! Especially if you live in hurricane areas. You won't regret it, I promise.

I live in tornado alley on an acreage so I need power for my well, septic, etc... I also have a large aquarium that I have a lot invested in that will die if I don't have power for more than 3-4 hours. When power went out I got tired of lugging my 8k generator out, running cords everywhere and have to fill the gas tank. Generac is the way to go. I purchased my 20kW and added the automatic transfer switch. Now it doesn't matter if I'm here or not, I know my house is protected.

Installed the 20KW unit to power seasonal maple sugaring pumping facilities. Needed a unit that was reliable. The cold weather packages provide extra assurance that it will function when needed in northern Vermont sugaring season. This is my second generac unit; the first was a 27KW unit which has proven reliable when power went down during sugaring and it powered the vacuum pump, the reverse osmosis machine, evaporator and filter press. The 20KW unit replaces a tractor pto winco generator which worked but required setup and take down time whenever needed; the automatic transfer switching of power to the generac units saves me considerable time when time is at a premium.

I just bought this Generator and had it installed and I must say that I am quite amazed at not only its sleek look and quietness, but at it extreme efficiency and the way it works. I don't seem to have to worry about a thing and I love that! Thanks Generac!!

My wife send me the drawing and specification on this product - as I was out in Germany and could not be present - the literature and drawings made my decision to go with this product. The product was install and the job was well done - I also was impressed how the load sharing works and how easy it will be to maintain this system.....