Skip to Content

Best Whole House Generator (Expert Generator Reviews 2020)

This article contains my four top picks for the best whole house generator for those sudden power cuts or going off-grid. Below, I’ll talk about the things you should look for in a generator, as well as diving into each best generator’s specifications, pros, and cons.

We have a generator that powers the whole house. We’ve got it set up so you can easily switch from mains power to the generator. It’s been a great generator, but she’s getting old and it’s time for an upgrade. We get lots of power cuts and being able to switch the whole house over to generator is awesome. 

Best Whole House Generator Top 4

If you want to skip straight to the best whole house generator, here’s our top 4:

We’ve also reviewed the best dual fuel generator. If you don’t need a whole house generator, check that article out!

One thing worth mentioning here is that the Kohler 20RESCL-200SELS and Generac 7043 Guardian Series generators came in a very close first and second place. When you look at the customer reviews on a website like Amazon,the former machine received an average of 4/5 stars from 37 reviews, while the latter scored 4.5/5 stars from 30 reviews. 

Features of the Best Whole House Generator

So, why do you need a whole house generator? To power your whole house! You may be looking for a generator to run continuously in an off-grid setting, or as a backup during power cuts. Don’t know about you, but we seem to be having a stormy year this year. I’d rather be prepared than caught out. Last year we were hit by a cyclone, leaving power out for weeks and the year before that we got flooded out. 

There’s also the question of fridges without power, leading to spoiled food. During the flood, my husband wasn’t home and I lost a freezer load of meat because I couldn’t get the generator going. My husband, Dan, moved heaven and earth to get home, going so far as to walk over the railway tracks to cross flooded roads! But, it was too late for the freezer food.


No way through this one!

Now that we have not 1 but 3 freezers full of food (we like to be prepared!), it would be a disaster A lack of internet or communications if you can’t charge your mobile devices – what if you live remotely and need help? Although, saying that, during the floods I described above, all communications were down either way. These are all valid reasons to have a backup power supply, which is exactly what a whole-house generator gives you in the event of an emergency. 

So, below, we’re going to take a brief look at some important information you should have before you decide to buy yourself a whole house generator. 

Whole House vs Standby Generators

If you’ve been browsing around, you’ve probably seen both of these types of generators come up. You could opt for a standby generator, but they’re generally less powerful. Here’s a quick breakdown of the advantages that a whole-house generator has over standby units:

  • Higher quality engines. You’ll typically be looking at something more akin to a vehicular engine on a whole-house generator. For a standby generator, it’s more like sticking a lawnmower engine on the side of your house. Less power!
  • Liquid cooling. This one isn’t a given. Some of the models here are air-cooled, but you’ve also got liquid-cooled options. This can cool the generator more quickly in the event of overloading outages. 
  • Less maintenance. You’ll typically enjoy longer periods of uninterrupted operation with the best whole house generators, needing less maintenance. 
  • Whole-house backup. They don’t call it that for no reason. With a whole house generator, it’s like nothing ever happened. With a standby generator, you’ll be choosing which valuable circuits you want to keep operational and which ones can be lost to the dark until the power’s back. 
  • Fuel efficiency and noise. Whole house generators have lower RPMs and are therefore usually quieter. They’re also more fuel-efficient and so cheaper to run — not much more to say about this one.

On average, your standby generator will run a smaller home within a wattage range of around 9,000 to 20,000 watts. They’ll save your refrigerated food, keep the air conditioner running, and give you some light. However, they can’t run everything at once or for a long period.

Your average whole-house generator, however, will range from about 20,000 watts to 50,000 watts, meaning you can keep the house running as it was before, until the power comes back. You can’t put a price on that kind of peace of mind in an emergency. 


What to Look for in a Whole House Generator

Fuel type

You can’t always come by fuel as easily as you might think. In more remote areas, having an abundant source of fuel can be tricky. Moreover, you need to work out what type is best; gas, LPG (liquid propane gas) or natural gas.

Generator size

This is where you’ll need some working knowledge of electrical circuitry, as well as the load of all appliances within your home.

You can usually find this within manufacturer documentation. This will often be printed in amperage, so if you need to work out your home’s power requirements in watts, then you can use this basic formula: (Starting Amps x Volts = Watts).

However, don’t buy a 20,000 watt capacity generator if your home’s demand at peak is 19,000 watts (for example). Why run the risk of running your generator at max capacity? Leave some leeway for additional appliances and for the sake of avoiding unexpected overloads. 

Choose a transfer switch

You’ll see some mention of “transfer switches” in the below comparisons. These let your generator jump into the ring if your power fails, and it does so by continuously monitoring for the flow of power through your utilities.

Without a switch, your generator might as well be a bench out in the yard. Have a look at your home’s electrical service panel and check the amperage on your main breaker. You’ll need a switch that matches this value. 

Safety Switches

What do we need in the way of safety switches? This information was kindly contributed by Rebecca and her husband, an electrical contractor who installs generators. Rebecca runs Restyled Homes, a wonderful blog where she shares simple and attainable home decor ideas.

“For a whole-house generator, you can install a manual transfer switch (MTS) or an automatic transfer switch (ATS). The description speaks for itself.

On an MTS, you will have manually operate a switch to generator power.

An ATS will sense a loss in power and automatically transfer the switch for you.

For portable generators, you can install a “generator inlet box” on the outside of your house, which will allow you to plug in your generator.  You will, however, need to install a device in your electrical panel that will prevent you from leaving both the generator breaker and the Main Breaker on at the same time.”

Best Brands for Whole House Generators

Rebecca and her husband mention:

Generac and Kohler are excellent brands for the whole house.

There are so many choices for portable generators out there.  Generac is one of them, but it doesn’t mean it is the best.

You will have to decide how much you want to spend, how many appliances and how many rooms you want to run off your generator, and go from there.  You will also have to decide if you want gasoline, propane, or dual fuel.

Oh… you can also get an electric start if you’re going to be fancy.”

Whole House Generator Tips

Some further tips from Rebecca regarding using your whole house generator.

“If you want a whole house generator, my advice is… call Generac, and they will hook you up with a local certified Generac installer in your area.

For portable generators that are wired to the electrical panel, my advice is to speak with the electrician who installed your generator inlet box, and they will instruct you on what breakers to switch and where to plug it in.

If you use a portable unit outside and simply run extension cords to it… my advice would be to adhere closely to the owner’s manual for start-up and go from there.  My only caution would be this; please use gasoline stabilized in your gas tank if you plan on storing the unit with gas in the tank!!”

Best Whole House Generator Reviews

1. Generac 7043 Guardian 22KW

Generac 7043 Home Standby Generator 22kW/19.5kW Air Cooled with Whole House 200 Amp Transfer Switch, Aluminum
$6,725.95 $6,147.00
  • True power technology delivers best-in class power quality (less than 5% thd) for Smooth...
  • Includes a 200 amp NEMA 3 (indoor/ outdoor rated) whole house Smart transfer switch
  • Generac evolution controller features LED indicators for generator status, utility power...
  • Tough, durable all-weather aluminum enclosure offers 3 removable sides for easy access for...
  • Battery not included. Generac Battery 7043 5819 Sold Separately.
We may earn a commission if you make a purchase, at no additional cost to you.
08/19/2022 07:23 pm GMT

This was a close call with the number 2 on the list, the Kohler whole house generator. It’s slightly more powerful than the Kohler. My main reason for having the Generac generator as the winner is that Generac generators and engines are engineered and built in the USA. That’s pretty awesome.

As for power, propane will give you 22,000 watts of power, whereas natural gas will give you 19,500 watts. It’s also capable of load balancing, supporting both high-power items — like stoves, air conditioning, and electric dryers — and lower power items — like phone chargers — simultaneously. 

There’s a remote monitoring feature built into the generator, which means you can check that everything’s working efficiently from the comfort of your still-lit home. You can do this via an app on your smartphone, tablet, or computer, so there’s no need to get off the couch. 

Generac 7043 – Guardian Series 22kW/19.5kW Air Cooled Home Standby Generator w/ Whole H… [More]

If you do need to check up on things using the built-in LCD, it’s a multilingual interface that’ll give you a detailed breakdown. This includes battery levels, as well as a countdown to the next maintenance interval so that you can make sure there’s no downtime between servicing, keeping your home protected. 


  • 5-year limited warranty; 
  • Rust and corrosion-resistant, powder-coated exterior housing; 
  • Built-in “self-test” mode to ensure everything’s working in case of an emergency. Nothing worse than losing power only to discover your generator is bust, too! 
  • High-tech LCD control panels support multiple languages and a range of remote monitoring systems. 


  • Accessing the terminal for the machine is a little tricky, plus there’s limited space inside for wiring; 
  • Generac has gained a sort of reputation among customers and other online sources for needing frequent maintenance, more so than some other brands. 

2. Kohler 20RESCL-200SELS

Kohler 20RESCL-100LC16 Air-Cooled Standby Generator with 100 Amp Transfer Switch Single Phase, 20,000-Watt
  • 20,000-watt air-cooled generator automatically starts up when the power goes out
  • Includes 200 Amp whole-house, service entrance rated, load shedding, automatic transfer...
  • Fast response--power to your home in 10 seconds; premium power quality; quiet operation
  • 100% corrosion-proof enclosure offers protection from even the harshest seaside conditions
  • Measures 48 by 26.2 by 29 inches; 5-year/2000-hour limited warranty Battery type needed -...
We may earn a commission if you make a purchase, at no additional cost to you.

This generator was a favorite on a lot of the lists I looked at, as well as getting strong customer ratings across the board. It’s powered by a super-reliable Kohler Command Pro engine, which has been custom-designed for commercial use. However, that doesn’t mean you can’t use it at home — it just makes it robust and reliable as a backup power supply. 

You can use either liquid propane gas, getting up to 20,000 watts of power, or natural gas, which will afford you 18,000 watts. You can also jump between the two by simply pressing a button. In layman’s terms, that’s enough to juice your washing machine, air-con, dishwasher, TV, and other electricals throughout your house, all at once. 


Image credit:

If we dig into the circuitry, this generator has hydraulic valve lifters, removing the need for interval stops during operation. In other words, you’ll get longer periods of continuous use out of the generator, just in case the power doesn’t come back on for a while. 


  • Restores power to your home quickly — within 10 seconds of a blackout; 
  • Machine housing is not only stylish but also corrosion-resistant; 
  • Built-in “PowerBoost” technology helps to power sudden large demands on the machine, without dropping smaller loads that are already sucking power. 


  • Ongoing maintenance costs are quite high, as are the costs for replacement parts; 
  • If you want to avoid costly installation bills, you’ll need to contact an official Kohler dealer. They also custom-mount the machine on their own concrete pads, reducing install cost and time. 

3. Champion Power Equipment 100294 Home Standby Generator 

Champion Power Equipment 100294 Home Standby Generator
  • Whole house 24/7 power - the Ats200 whole house transfer switch with demand control...
  • Quietest-in-class - thanks to advanced sound dampening and a specially designed low-tone...
  • Reliable - 24-volt starting system operates in sub-zero or extreme heat (between -22...
  • Powerful - the 14-kilowatt generator provides 14, 000 watts of continuous power on propane...
  • Champion support - includes 10-year limited with free lifetime technical support from...
We may earn a commission if you make a purchase, at no additional cost to you.

This whole house generator is quite nice to look at. In fact, you could be forgiven for mistaking it for an outdoor storage unit. It’ll safely operate at extremes in temperature, giving you power in case of a blackout. 

Under the hood is a 754-cc OHV engine that can be powered with either natural gas or propane. And it’s reasonably quiet when in operation; not the quietest, but not loud enough to be disturbing. If you want to get into specifics, it’s around the 63.5 decibel range. This is partly thanks to a low-tone muffler and sound-muffling lining. 

If you choose to power this machine with liquid propane, you can expect around 14,000 watts of continuous power output. On natural gas, you’ll get a power output of 12,500 watts. 


  • 10-year warranty; 
  • The unique gull-swing design makes it easy to access the internal control panel; 
  • Robust, durable materials that are built to be outdoors, yet can easily be removed and maintained; 
  • A built-in 24-volt starting system can function in sub-zero temperatures of minus 22° F, right up to 104° F. 


  • Bulky and heavy — yet getting someone else to install this machine is pretty pricey; 
  • Not the quietest generator around, but more reasonable than some others. Middle-of-the-road where noise is concerned! 

4. Generac 7033 Guardian Series 11kW/10kW Air Cooled

Generac 7033 Guardian Series 11kW/10kW Air Cooled Home Standby Generator with Whole House 200 Amp Transfer Switch (not CUL)
  • True Power Technology delivers best-in class power quality (less than 5% THD) for smooth...
  • Includes a 200 Amp NEMA 3 (indoor / outdoor rated) whole house smart transfer switch
  • Generac's Evolution Controller features LED indicators for generator status, utility power...
  • Tough, durable all-weather aluminum enclosure offers 3 removable sides for easy access for...
  • Battery Not Included. Generac battery model 5819 sold separately.
We may earn a commission if you make a purchase, at no additional cost to you.

Coming in last on the list, the Generac 7033 has an output that’s nearly half of the other machines listed about. But I’ve picked this one because it had some stellar reviews across the board, in addition to, of course, being cheaper due to the lower output. Let’s face it; not everybody is going to need as much as 18-20,000 watts in the event of a blackout. 

Under the hood, you’ve got Generac’s True Power Technology, which promises “best-in-class” power quality, with less than 5% THD. Was that as confusing to you as it was to me originally? THD means ‘Total Harmonic Distortion’ — the amount of THD stated will influence your generator’s performance. The lower the number, the better. Above 6%, you can start to see some issues with your electricals. 

This whole house generator has some pretty useful quirks. For example, aside from the remote monitoring features, it also has LED indicators built into the Evolution Controller. These lights will tell you the generator status, utility power presence, as well as whether the generator needs maintenance. 


  • The sturdy aluminum body is resistant to harsh weather conditions; 
  • Link Remote Monitoring lets you check on the generator’s status and service intervals remotely from your device; 
  • Depending on the appliances you’re running, the generator’s variable speed will auto-adjust the power output. 


  • Generac battery is not included! You’ll need a Generac battery 5819 for this whole house generator.
  • Additional costs for installation — it’s a little too tricky to get this up and running yourself; 
  • I’ve read some reports of warranties not being honored by the manufacturer, but honestly, you’ll need to take that with a pinch of salt. 
Generac 5819 Model 26R Wet Cell Battery For All Air-cooled Standby Generators, 12 Volts DC, 525 Cold Cranking Amps, Dimensions (LxWxH) 8.7" x 6.8" x 7.6"
  • Family / Style:58
  • Amps:525
  • Volts DC:12
  • Type:Battery, Standby Generator
  • Size:26R
We may earn a commission if you make a purchase, at no additional cost to you.
08/19/2022 01:53 am GMT

Best Whole House Generator Winner

Choosing a winner was a little tricky, owing to the neck-to-neck race between the two in the top spots. So, I’ll finish with this: if you need a little more power to account for all your appliances, plus that all-important buffer you should keep beyond that total, opt for the Generac 7043 Guardian 22KW. It’s also made in the USA which gives it a definite UP for me. Otherwise, if the Kohler 20RESCL-200SELS exceeds your power needs, it’s an equally good choice. 

Amazon product

Do you have a backup whole house generator or do you solely run on a generator? Let us know which is your best whole house generator and your experience with it. Has it served you well?


  • Jack of all trades, master of some. Wild garden grower. Loves creating stuff. From food forests and survival gardens to soap and yoghurt. A girl on a farm with two kids and one husband (yep, just one - although another one would be handy). Weirdly enjoys fixing fences and digging holes. Qualified permaculture teacher and garden go-to.

Taylor Hansen

Tuesday 11th of August 2020

It's good to know that a whole-house generator has lower RPMs and won't miss a beat in a power outage. I'm wanting to get a generator for my new house in case of the power going out in a storm. Should I look for bigger generators to put in the back or have a professional install it for me?


Tuesday 11th of August 2020

Hi there Taylor! It is generally recommended to get a professional to install it for you. They can make sure it's all wired up correctly and can install an automatic switch over system so you don't have to go out in a storm to manually turn it on. Portable, smaller generators can still be very helpful to run a couple of lights or small appliances though, so it depends on your preferences. Read more expert generator tips or my newest article: Does a whole house generator add value to your home?