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Rating The Generac Guardian 5875 Generator – Ready For Emergencies

21 December 2011 886 views No Comment

In my Generac Guardian 5875 Generator review I talk about why this machine is the best whole house stationary generator currently on the market.


When an ice storm hits and knocks out your power for seven days or more and the temperatures are in the single digits, then you’ll really appreciate having a whole house generator. A smaller portable generator is great for a few days of power outage, but for longer than that you’ll need a whole house unit.

Although a stationary electric generator is a larger investment than a portable generator, in the long run it is a better investment. The max power output for portable generators usually tops out around 10,000 watts, and these higher wattage models usually cost about $1,500 – $2,000. Stationary generators for single family residential use typically start at 12,000 watts of power output and go as high as 60,000 watts. 20,000 watts is typically enough to power just about everything you’ll need in a large single family home. The Generac Guardian 5875 is a 20,000 max watt model.

20,000 watts is enough power to run your whole house including the air conditioning, all of your lights, stove, washer, dryer, microwave, and hot water heater. Having running water will prevent your pipes from freezing if the power outage is during the winter. Owners with houses that are 1,800 to 2,000 square feet, or larger, will have more than enough power with a 20,000 watt machine to run their whole house. Basically when there’s a blackout and the Generac 5875 turns on, you won’t even know the main power’s out.

Think about how much money you’ll spend without power. If you go to a hotel for 7 days, you’re looking at at least $700 – $800 just for the room, plus food and eating out, which for a family can run you another $500 or so easily. That is money that can go a long way towards buying a good whole house stationary generator. If the power is out all over town, even at the hotel, then you are left freezing in your home and using whatever means you can to stay warm and eating cold tuna and beans out of the can until the power gets restored. If the power outage occurs during the summer months then all your food will spoil. Nobody wants that.

Although this site is primarily about portable electric generators, I thought it would be helpful to talk about one of the best stationary generators you can buy, the Generac Guardian Series 5875 20,000 watt generator. This generator has the highest ratings of any stationary machine I’ve seen out there and owners just rave about how good it is. Here is what you can expect with this machine.

This video provides a good overview of benefits of Generac Guardian Series.

Getting Your Generac Set Up And Running Properly

One of the great things about the Guardian 5875 is that it comes with a transfer switch. The cost of the switch is already included in the price of the unit, unlike other models where you have to go out and buy a switch, which typically costs $200-300. The Generac Guardian series of generators also come with detailed instructions on how to install the generator and transfer switch. The wires are all color coded and marked.


If you are not comfortable with putting the unit in yourself, I would suggest hiring an installer. Canadian callers and US residents can reach Generac by phone on Monday through Friday at 1-888-GENERAC (1-888-436-3722) from 7 a.m. To 6 p.m. CST and they’ll send out a certified installer from your area that will get everything set up correctly.

Those calling from outside Canada or the U.S. can reach Generac Customer Support, Sales, and Service departments by dialing 1-262-544-4811 during the same hours.

Choose From 2 Power Options

You can choose to have the Guardian 5875 run on either propane or natural gas. If you have a natural gas line running to your home already, experts suggest have a separate stand-alone line run to the generator. A one inch line should be sufficient.

If you are worried about damage to the natural gas lines from an earthquake type of natural disaster for example, or if you don’t have any natural gas lines running to your home, then a propane tank will get the job done. Most homeowners use a 100 gallon tank.

Generac Guardian Series 5875 20,000 Watt generator products feature the only EPA-certified, factory-installed Bi-Fuel system. Other systems offer aftermarket field-retrofitted parts. By contrast, Generac Bi-Fuel generator engine components are specially designed and engineered with precision calibration that allows both natural gas and propane operation. Such duality reduces hazardous on-site fuel storage drastically while affording much greater fuel efficiency and lower operating cost.

This video talks about the Generac overhead valve engine. The engine is designed to get a 3 to 4 time longer life than most generator engines which are typically just modified lawnmower engines.

Quick Starting With No Effort On Your Part

The Generac Guardian Series 5875 20,000 Watt generator will start automatically 10-15 seconds after the main power goes out. You don’t have to do anything. The digital control panel and sensors tell the unit when the main power goes out and will turn the machine on. The Guardian is connected to your home with an automatic transfer switch so that there is no need on your part to turn anything on. And the Generac is powered with natural gas or propane so you don’t have to go out and fill it up with gas.

With a standard portable generator you have to go outside, pull it out of storage, fill it up with gas and pull start it. Then you need to plug in all of the appliances you want to run. That can be a real pain, especially in the dark and cold. Once everything is set up with the Guardian 5875 you won’t need to do anything, just wait a few seconds and your power will come back on just like the main power were still on.

When the main power is restored, the switch back in nearly instantaneous with the Generac. And you won’t need to go turn it off; it will turn off automatically after cooling down for a couple of minutes.

Compatible With Sensitive High-Tech Electronics

When I say the Generac will run everything, I mean everything, including sensitive electronics like your computer, flat screen TV, and DVD player. Many generators on the market do not produced what is called clean power. The power they produce can damage electronic devices. No need to worry about that with the Guardian 5875.

The Generac Guardian 5875 Generator Is Self Maintaining

Well, it won’t change the oil on its own, you need to do that. :) But the Guardian can be preprogrammed to self-perform routine maintenance checks. This capability ensures that all essential components remain in excellent working order without owner intervention.

Automated self-tests of all internal parts may be scheduled at weekly intervals. Basically the unit comes on once a week at half speed for a few minutes to make sure everything is in good working order. While running its maintenance test, the Guardian will circulate the oil and perform a self diagnostic at half the maximum power level. It will even charge its own battery. The last thing you want is to have a power outage and not have your generator come on because it hasn’t been run in a couple of years.

The average Generac unit requires full-scale professional care only once every 200 operational hours or 2 calendar years, whichever comes first.

A Durable Design Keeps the Generac Guardian Looking Good Over Time


The all-aluminum outer enclosure affords outstanding resistance to corrosion and other disadvantageous external elemental effects. With such a sturdy outer cover you’ll have no problem operating your Generac in the harshest weather without any of the components deteriorating. Plus the cover looks pretty good and won’t look out of place or tacky on the outside of your home.

Generac also uses a special binding process to protect the cover from corrosion and break down. They call it their RhinoCoat system. Basically it prevents the unit from becoming faded and looking bad from sitting out in the sun and being subject to harsh weather conditions over time.

More Pros

  • In addition to the fantastic benefits I talk about above, you can also expect the following.
  • An easy to read digital control panel – The control panel will tell you if the unit needs an oil or filter change or any other type of service.
  • Environmentally friendly – The Guardian 5875 meets all California Air Resources Board (“CARB”) clean air emission standards, which means if you live in that state you can use this generator without problems.

The Cons

  • It’s best to go with professional installation – Even though Generac has installation instructions and says that you can do it yourself, it’s best to get your Guardian professionally installed. Other owners say basically the same thing in their reviews.
  • You need to buy a separate battery – A 26R 12-volt 525 CCA battery is required for start-up power and will run you about $100.
  • Heavy – This unit weighs in at over 450 pounds. It’s stationary so you don’t have to worry about wheeling it around like you would with a portable generator, but because of the weight you’ll need to have a secure and stable base for it.

The Generac Guardian 5875 Generator Gets 4.5 out of 5 stars

Check for the Best Deals for the Generac Guardian Series 5875 20,000 Watt Standby Generator.

What Others Are Saying

All online consumer review sources found the Generac Guardian Series 5875 20,000 Watt generator to be well worth the price they paid. Even after factoring in added expenditures for external supporting structures, professional installation, and separately sold ancillary components, customers found that advantages far outweighed any associated cost(s). Consumer reviews also highly recommended the purchase of a biannual service contract for $400 that includes full spark plug, battery, and engine oil changes.

Many owners also talk about how the Generac powers all of their appliances and runs very quiet. They also love having the generator just turn on in a few seconds after the main power goes out and not having to do anything. Several owners talk about long power outages of several days or more and not having any problems with the Guardian 5875.


You can read more details about the features of this machine in the Generac Guardian Series 5875 spec sheet.

The Generac Guardian 5875 Comes With the Following

  1. Fuel line and connector
  2. Pad for mounting the generator – This sturdy composite pad is already attached to the unit so you won’t need a concrete pad built for the unit unless local code requires it.
  3. Connection box for outside
  4. 200 amp Nexus Smart Switch NEMA 3R service entrance rated transfer switch
  5. Owner’s manual
  6. Installation guide

Where To Buy The Generac Guardian 5875 Generator

You can look at buying the Guardian from a local electrician and having them install it for you, but if you want to save some money you can buy the unit and install it yourself. If you’re not comfortable installing, you can still buy the unit yourself and save the cost of any dealer mark-up and then hire someone to install. Visit the Generac Dealer locator to find an authorized dealer and installer near you.

Now for buying it yourself, I was surprised to find this unit on Amazon.com. When I checked they were selling it for a 22% discount which amounted to over $1,200 off. Now that’s a really good price. You can check here for the best deals on the Generac Guardian Series 5875 20,000 watt standby generator.

Amazon even offers free shipping for this big 450 pound machine. You can also pick up any extra extension cords you may need for outdoor appliances you want to run, and you can buy the battery that the Guardian needs as well.

Best Place To Read More Reviews

There are over 110 owner reviews on the Generac website for the 20,000 watt Guardian. The average rating here is 4.8 out of 5 stars, which is fantastic for a generator. There are also a dozen or so reviews on Amazon.com with an average rating of 4.5 out of 5 stars. Click here to read more Generac Guardian Series 5875 standby generator reviews.

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