Key takeaways
- Generac's published ratings put the Guardian 14kW at 14,000 watts on propane and 14,000 watts on natural gas, so the fuel does not change what it carries.
- A Generac 14kW is usually sized for essential circuits: the refrigerator, lights, outlets, internet, a well or sump pump, and sometimes one smaller air conditioner.
- The number that decides it is the total of everything running at once, plus the extra a motor draws as it starts.
- If central air on a large house is on your list, look at the 18kW or 22kW instead, or plan load management.
What can a Generac 14kW run is the right question to ask before you buy one, because the answer depends on your house and not on the label. Generac's published ratings put the Guardian 14kW at 14,000 watts on propane and 14,000 watts on natural gas. That is a real amount of power, and for many homes it covers everything that matters in an outage. For others it falls short the moment the air conditioning tries to start. This guide walks through how to tell which side of that line your home sits on.
The figures here come from Generac's own product page, which we cite on our Generac 14kW generator page, along with the engine, the breaker and the weight Generac publishes.
What the 14kW rating means
A standby generator's rating is the most it can carry continuously. On the 14kW, Generac lists the same figure for both fuels, which is not true of the larger sizes. That makes the 14kW simple to plan around: whether your home is on natural gas from the street or on a propane tank, the target is the same 14,000 watts.
The rating is not a list of appliances. It is a ceiling. Everything that runs at the same moment has to fit under it, and a motor needs more than its running figure for the second or two it takes to start. That starting surge is where most sizing mistakes happen.
Essential circuits: the job the 14kW is usually sized for
Most homes that land on a 14kW are not trying to run the whole house exactly as normal. They want the things that make an outage livable and keep the house from being damaged. A typical essential list looks like this:
- The refrigerator and a freezer, so food does not spoil.
- Lights in the rooms you use and the hallways you walk at night.
- Kitchen and living room outlets for phones, a microwave and a coffee maker.
- The internet router and a home office.
- A well pump or a sump pump, where the house has one.
- The furnace fan or a smaller air conditioner, if the list has room for it.
The nameplate on each appliance gives its running watts or its amps and voltage. Add the ones that will run together, and you have the starting point for the decision. We do this with you at the sizing visit, room by room, so nothing is guessed.
That visit is free and comes with a written price for the install. You can book a free Generac sizing visit and we will list the loads with you.
Why air conditioning decides the size in Texas
In a San Antonio summer, central air conditioning is usually the largest single load in the house, and its compressor is a motor. When it starts, it draws far more current for a moment than it does while it runs. A generator that carries the running load easily can still struggle with that start, which shows up as lights dipping or the generator straining.
For a 14kW, this is the dividing line. A smaller home with one modest air conditioner can often fit it alongside the essentials. A larger home with a big central system, or two systems, usually cannot without help. That help is either a soft starter on the compressor, which reduces the starting surge, or load management, which keeps the biggest loads from running at the same time.
Load management stretches a 14kW further
Load management lets a generator serve more of the house than it could run all at once. The transfer switch or a module beside it watches the load and holds back a large appliance, such as an air conditioner, a water heater or a dryer, until there is room for it. When the load drops, the held appliance is allowed to run.
On a 14kW, load management is often what makes the difference between essential circuits only and something close to normal life. It does not create power the generator does not have. It shares the power it has, in turn, so the total never goes over the rating.
We cover the switch side of this in our guide to generator transfer switch types, including essential circuit switches and load managed whole house switches.
Whole house or essential circuits on a 14kW
There are two ways to wire a 14kW. An essential circuit switch moves a chosen set of circuits to the generator, and everything else stays dark. A whole house switch sits at the service and moves the entire panel, with load management keeping the total in range. The first is simpler and suits a home that has decided what it needs. The second suits a home that wants most of the house available and is willing to let the system decide what runs when.
Either way, the generator and the utility can never feed the house wiring at the same time. That separation is what the transfer switch is for.
When the 14kW is not enough
If your list includes central air on a larger home, an electric range you want to cook on, a pool pump and an electric water heater, the total will run past 14,000 watts quickly. At that point the next sizes up are worth a look. Generac rates the 18kW at 18,000 watts on propane and 17,000 on natural gas, and the 22kW at 22,000 on propane and 19,500 on natural gas.
We walk through what the next size handles in what can a Generac 18kW run, and the larger sizes are on our Generac generators page.
Mistakes to avoid when sizing a 14kW
The most common mistake with a 14kW is choosing it from a list of what the house has, rather than what has to run at the same time. A home can have a range, a dryer, a water heater and an air conditioner and still fit a 14kW, if only some of them run together during an outage and the rest wait or stay off. The second mistake is the opposite: forgetting the air conditioner's start and sizing from its running figure alone. Read the plate on the outdoor unit before you decide.
What the install involves
A 14kW install is the same work as any home standby generator. We set the unit where the setbacks allow, install the transfer switch, wire it to your panel, pull the electrical permit, and start the unit up and test it under load before we leave. The gas line is a licensed plumber's work and is quoted separately, and we schedule the plumber with the electrical work so the unit is ready on the same day.
The full install is laid out on our Generac generator installation page. We sell and install Generac home standby and commercial generators.
What a 14kW costs
The installed price is the unit plus the transfer switch, the wiring, the gas line, the placement and the permit. A 14kW unit is the smallest of the sizes we cover here, but the other parts of the price do not shrink with it. A long run from the unit to the panel, or a panel that needs work first, can matter more than the size of the generator.
Our Generac generator cost guide explains what moves each part of the price, and we write your number after the sizing visit.