Key takeaways
- Generac vs Kohler is a fair comparison: both make air-cooled home standby units and larger liquid-cooled models, and both pair them with automatic transfer switches.
- Compare the size you actually need from a load list, not the largest unit either brand sells.
- Read the current written warranty for the exact model you are quoted. Terms change, and they differ by model and by size.
- Ask who will service the unit after the install, and how quickly parts reach San Antonio. That matters more over ten years than the badge on the enclosure.
Generac vs Kohler is the first question most San Antonio homeowners ask once they decide a standby generator makes sense. Both companies build home standby generators that sit outside on a pad, run on natural gas or propane, and start on their own when the utility power drops. Both pair the generator with an automatic transfer switch so the house moves to generator power without anyone flipping a breaker. So the honest answer is that either brand can do the job. The better question is which unit, from which company, fits your house, your budget and the service you will need for the next decade.
A plain disclosure before we go further: We sell and install Generac home standby and commercial generators. So this guide sticks to the things you can check for yourself, whichever brand you choose.
Start with the size you need, not the size on the brochure
Both brands sell a range of sizes, from smaller air-cooled units meant to carry essential circuits up to larger units that can run most of a house, and liquid-cooled models above that. Comparing the largest unit from one brand with a mid-size unit from the other tells you nothing. Compare like with like, and start from what your house actually needs.
That number comes from a load list: the air conditioning, the refrigerator and freezer, the well pump if you have one, the water heater, the cooking, the medical equipment, and anything else you want running during an outage. In a Texas summer the air conditioner usually decides the size, because a compressor draws a large current for a moment every time it starts. Once the load list is done, you can put two quotes side by side at the same output and compare them fairly.
We go through that load list in detail in our guide to sizing a Generac generator for a Texas home, and the free in-home generator sizing visit is where we build it with you, room by room.
Air-cooled or liquid-cooled
Most home standby generators from both companies are air-cooled. The engine is cooled by air moved across it, the way a lawn mower engine is, and that keeps the unit compact and the price lower. Larger homes, and homes that want to run nearly everything for a long outage, sometimes move up to a liquid-cooled unit, which uses a radiator and coolant like a car engine and is built for heavier, longer running.
Both brands offer both types, so this is a decision about your house rather than about the brand. If an air-cooled unit sized from your load list covers what you need, it is usually the simpler choice. If the load list pushes you toward the top of the air-cooled range, ask to see a liquid-cooled option from each brand as well, so you can compare running time, maintenance and installed cost.
Transfer switch options
The transfer switch is the part that decides what the generator powers and when. Both companies sell automatic transfer switches made to work with their own generators, including whole house switches that sit at the service and smaller switches that carry selected circuits. Both also offer ways to manage large loads, so an air conditioner or a range can be held off for a moment while the generator picks up the rest of the house.
What matters for a comparison is whether each quote uses a switch that fits your service and your panel. A house with a meter and main breaker combination outside needs a different arrangement from a house with the main breaker inside the panel. Ask each installer to show you which switch they are using, where it will be mounted, and which circuits it will carry.
Our post on generator transfer switch types walks through automatic and manual switches, whole house and essential circuit setups, and load management.
Monitoring from your phone
Both companies offer a way to check on the generator from a phone. Generac calls its system Mobile Link, and Kohler calls its system OnCue. Either one can tell you whether the unit ran its exercise cycle, whether it is ready to start, and whether it has logged a fault. Features and any subscription terms change, so look at the current version for the model you are quoted rather than relying on what a neighbor had a few years ago.
Monitoring is worth having. A standby generator sits unused for months, and the time you find out a battery is weak should be a quiet afternoon, not the first hour of an outage.
Warranty: read the written terms for the exact model
Warranty is where comparisons go wrong most often, because people compare what they heard rather than what is written. Coverage differs by brand, by model, by size and sometimes by how the unit is installed and registered. Ask each installer for the current written warranty for the exact model in the quote, and read what it covers, for how long, and what it asks of you, such as maintenance records.
Also ask what the installer covers on their own work. The manufacturer's warranty covers the machine. The wiring, the transfer switch installation and the connection to your panel are the installer's work, and you should know who stands behind them.
Service, parts and who comes out after the install
A standby generator is a machine with an engine, and it needs maintenance for as long as you own it: oil, filters, spark plugs, a battery, and a check of the transfer switch. Before you choose a brand, ask who will do that work in San Antonio, how quickly they can get parts, and whether the company that installs the unit will also service it. A generator from either brand is only as good as the service behind it in your area.
Our guide to Generac generator maintenance covers what a service visit includes, and our generator service and repair page explains how we handle maintenance and repairs on standby units.
What the install includes, whichever brand you pick
The install is the same kind of job for either brand. The unit is set on a pad outside, at the clearances the manufacturer and the code require from windows, doors and the property line. The transfer switch is mounted and wired to your service and panel. The generator is connected to the transfer switch. The gas line is run from the meter to the unit. And the electrical work is permitted and inspected.
Gas line and gas connection are not included in our electrical price. That is a licensed plumber's work and we quote it separately. We coordinate the plumber so the gas and the electrical work are scheduled together, and we pull the electrical permit with the City of San Antonio Development Services Department or your suburban city's permit office.
For how we install Generac units specifically, see our Generac generators page. For standby generators in general, including service and repair, see our generator installation service.
How to compare two quotes side by side
- Is each quote sized from a load list for your house, at a similar output?
- Air-cooled or liquid-cooled, and why?
- Which transfer switch, where is it mounted, and which circuits does it carry?
- How are large loads like the air conditioner managed?
- Is the gas line included, or quoted separately by a licensed plumber?
- Who pulls the electrical permit and meets the inspector?
- What does the written warranty for this exact model cover?
- Who services the unit after the install, and how are parts sourced?
Two quotes that answer every one of those questions in writing can be compared honestly. A quote that leaves several of them blank is the one most likely to grow after you sign.