Struggling to power your hot water heater during outages? Finding the right size generator is crucial.
We guide you through the specs and needs, allowing you to enjoy uninterrupted hot water, even during the most inconvenient times. No more cold surprises!
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What Size Generator To Run Hot Water Heater?
To run a hot water heater, you need a generator capable of supplying at least 4500 running watts to cover the heater’s operational needs. A model offering around 6000 watts is ideal to handle the higher starting watts usually required when the heater is initially turned on.
Chart on Generator size to run hot water heater:
| Size | Wattage | Recommended Product |
|---|---|---|
| Small | 3000 watt | Craftsman 3000i Inverter 50 St/CSA |
| Medium | 5000 watt | Champion Dual Fuel Portable Generator |
| Large | 7500 watt | Westinghouse WGen7500 Portable Generator |
| Maximum | 9000 watt | WEN 420cc Transfer Switch Portable Generator |
Types of Generators Suitable for Running a Hot Water Heater
Generators can be divided into four main categories:
Portable Generators
Portable generators are generators that you can move around easily. They usually have wheels and handles that make them easy to transport.
They are also relatively cheap and easy to use. You just need to fill them with gas or propane, plug in your appliances or devices, and turn them on.
Portable generators are good for running a hot water heater because they can provide enough power for most water heaters.
They are also good for emergencies or camping trips because they can run on different types of fuel and can be used anywhere.
Inverter Generators
Inverter generators are generators that use a special technology that converts the power from AC (alternating current) to DC (direct current) and then back to AC.
This makes the power more stable and clean, which means it is safer for sensitive electronics like computers or TVs.
Inverter generators are good for running a hot water heater because they can provide enough power for most water heaters.
They are also good for use with other appliances or devices that need clean and stable power.
They are also quieter and more fuel-efficient than portable generators, which means they are less annoying and more eco-friendly.
Standby Generators
Standby generators are generators that are permanently installed in your home.
They are connected to your natural gas or propane line, which means they don’t need refueling.
They also have an automatic transfer switch, which means they turn on automatically when the power goes out.
Standby generators are good for running a hot water heater because they can provide enough power for any size of the water heater.
They are also good for providing backup power for your entire home, which means you don’t have to worry about losing electricity during a storm or a blackout.
Diesel Generators
Diesel generators are generators that run on diesel fuel, which is a type of oil.
Diesel fuel is cheaper and more widely available than gas or propane, which means diesel generators are more economical and convenient to use.
Diesel generators are good for running a hot water heater because they can provide enough power for any size of water heater.
They are also good for providing backup power for your home or business, especially if you live in a remote area where gas or propane is not easily accessible.
How to Determine the Power Requirements for a Hot Water Heater?
To determine the power requirements for a hot water heater, you need to follow these steps:
Listing Out Appliances
The first step is to list out all the appliances and devices that you want to use with your generator.
This includes your water heater and any other appliance or device that uses electricity in your home.
For example, you might want to use your generator to run your water heater, refrigerator, microwave, TV, laptop, lights, fans, etc.
Calculating Total Wattage
The second step is to calculate the total wattage of all the appliances and devices that you listed.
You need to find out the wattage of each appliance or device and add them up.
You can find out the wattage of each appliance or device by looking at the label on it or checking the manual that came with it.
It should tell you how many watts it uses when it is running or starting up.
For example, let’s say you want to use your generator to run these appliances and devices:
| Appliance/Device | Running Watts | Starting Watts |
|---|---|---|
| Water Heater | 4500 W | 6000 W |
| Refrigerator | 600 W | 1200 W |
| Microwave | 1000 W | 1000 W |
| TV | 200 W | 200 W |
| Laptop | 100 W | 100 W |
| Lights | 300 W | 300 W |
| Fans | 200 W | 200 W |
You can calculate the total wattage by adding running watts and starting watts.
You should only take into account the highest starting wattage since you won’t start all your devices at once.
The appliance that has the highest starting wattage is the water heater, which needs 6000 W to start.
So, you need to add up the running watts of all the appliances or devices and the starting watts of the water heater.
The total wattage is:
4500 + 600 + 1000 + 200 + 100 + 300 + 200 + (6000 – 4500) = 9400 W
So, you need a generator that can provide at least 9400 W of power to run all these appliances and devices, including your water heater.
Considering Additional Factors
When determining power requirements for a water heater, consider additional factors such as the size of the water tank, as larger tanks require more power.
The temperature of incoming water is also crucial; colder water demands more power to heat.
Frequent and prolonged usage of hot water necessitates a higher power requirement to maintain the desired water temperature.
Add about 20% extra power to your total wattage to account for these factors. This will give you some buffer in case your power needs to change or increase.
For example, if your total wattage is 9400 W, you might want to add 20% of extra power to it. That is:
9400 x 1.2 = 11280 W
So, you might want to choose a generator that can provide at least 11280 W of power for your water heater and other appliances and devices.
Factors Influencing the Selection of Generator Size
Here are some factors that might influence your generator size selection. These factors include:
Fuel Efficiency
When a generator is fuel-efficient, it consumes less fuel and runs longer on a single tank of fuel. Choosing a generator with high fuel efficiency will save you time and money on fuel.
The fuel consumption and run time of a generator are important to compare fuel efficiency. Consider two generators that each generate 5000 Watts of power.
Using 0.75 gallons of fuel per hour, Generator A runs 8 hours, while Generator B runs 6 hours.
Noise Level
The louder your generator runs, the more noise it makes, which disturbs you and your neighbors.
If you want your hot water without annoying anyone, choose a generator with a low noise level. You can compare noise levels by using the decibel rating.
The higher the decibel rating, the louder the sound. For example, let’s say you have two generators that each have a decibel rating of 68 dB.
Generator Features
You can start your generator by pressing a button instead of pulling a cord. The generator will shut off automatically if it runs out of oil, preventing it from destroying its engine.
Besides controlling your generator’s voltage, this feature lets you know how much fuel you have left so that your appliances don’t get damaged.
The more outlets your generator has, the more devices or appliances it can run at once. With larger, stronger wheels and handles, you can transport your generator more easily.
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Budget Considerations
A generator’s price is how much you pay to buy it. You should compare the cost of different generators based on their price and operating costs.
If you have more money, you will have better options. Your budget affects the type and size of generator you can afford.
Let’s say you have two generators that generate 5000 W. Generator A costs $500 and operates $50 per month.
Generator B costs $800 and operates for $40 per month.
Brand and Warranty
You can trust the brand and warranty of your generator because they are its reputation and guarantee.
A long and strong warranty protects you against defects or damage. The more reputable and reliable the brand, the more confident you can be.
Choose the right generator based on how satisfied and secure you feel. You can compare the brand and warranty of different generators by reading reviews and coverage.
We have 100 reviews of Generator A and a 2-year limited warranty. There are 50 reviews of Generator B and a 3-year warranty.
Local Regulations and Safety Standards
Generally, the more strict the rules and requirements, the more compliant you should be with generators.
Your generator needs to meet or exceed local regulations and safety standards because they influence its legality and safety.
Find out what the maximum decibel level of your generator is before using it. Check with your local environmental agency or generator manufacturer before using your generator.
You should also check with your local building department or utility company before installing or using your generator.
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Best Generator To Run Water Heater
1. Craftsman 3000i Inverter 50 St/CSA
- Built in Handle – Easy mobility; carry with one hand
- Steady power – Our technology makes safe, clean power for your electronics
- Easy start – Start/Stop/Choke dial makes starting quick and easy
- Boost of Power – 50 percent more starting capacity allows you to do more with a smaller product
- Ultra Quiet Design with High Performance – Perfect for camping and tailgating
2. Champion Power Equipment 6900/5500-Watt Dual Fuel Portable Generator
- Dual Fuel – Operate your 5500-watt portable generator right out of the box on either gasoline or propane, plus the unit holds 1.2-quarts of oil and has a low oil shut-off sensor
- Fuel Safety Switch – Our patented fuel selector switch allows for quick and safe switching between fuel sources
- Intelligauge – Keep track of voltage, hertz and run-time hours to easily monitor power output and track maintenance intervals
- Outlets – One 120/240V 30A locking outlet (L14-30R) and four 120V 20A GFCI protected household outlets (5-20R)
- Champion Support – includes 3-year limited warranty with FREE lifetime technical support from dedicated experts
3. Westinghouse WGen7500 Portable Generator with Remote Electric Start
- 7500 Running Watts and 9500 Peak Watts; Remote Start With Included Key Fob, Electric and Recoil Start; Up to 11 Hours of Run Time on a 6.6 Gallon Fuel Tank With Fuel Gauge
- Features Two GFCI (Ground Fault Circuit Interrupter) 5-20R 120V Household Duplex Receptacle and One L14-30R 120/240V Twist-Lock Receptacle; All Outlets Have Rubber Covers for Added Safety
- Plug-and-Play: Comes with a Remote Start Key Fob, 12V Battery Charger, Oil, an Oil Funnel, a Tool Kit, and a User’s Manual to Get You Started Right Out of the Box (Minimal Assembly Required)
- Powered by a 420cc Westinghouse 4-Stroke OHV Engine Featuring a Long-Lasting Cast Iron Sleeve with Automatic Low Oil Shutdown and Digital Hour Meter. Output Ready Indicator : No.
- All Westinghouse Portable Generators are Functionally Tested in the Factory and May Contain Minimum Residual Oil and/or Fuel Odor; EPA and CARB Compliant; Backed by 3-Year Limited Service, Labor, and Parts Coverage with Nationwide Customer Service Network
4. WEN GN9500 420cc Transfer Switch 120V/240V 9500-Watt Portable Generator
- Keep your family safe with 9500 starting watts and 7500 running watts of power
- Remote electric start allows users to turn the generator on and off from up to 160 feet away
- Transfer-switch-ready 30-amp 120V/240V NEMA L14-30R outlet perfect for emergency backup
- Packed panel includes four standard 120V 15-amp outlets, one RV-ready 120V 30-amp TT-30R outlet, one 12V DC outlet, one L14-30R outlet, and a digital readout
- Features an EPAIII and CARB compliant 420cc 4-stroke engine, a wheel and handle kit, a 6-gallon gas tank, a spark arrestor, low-oil shutdown, and a two-year warranty
FAQs About Right Size Generator To Run Water Heater
What Is The Best Size Generator For A Tankless Water Heater?
You should use a 7500-watt inverter generator or even higher.
Can A 7500-Watt Generator Run A Water Heater Efficiently?
A generator with 7500 watts is a popular choice among homeowners to heat the water.
Will A 5000 Watt Generator Run A Water Heater?
Yes, a 5,000-watt generator can run an electric water heater.
Final words
A generator is a life-saving device, especially during storms or power outages, as well as in winter.
But when it comes to running a water heater, the right size generator is needed to operate this electric appliance smoothly and serve hot water to the whole house.
Hopefully, now you know what size generator to run hot water heater as well as other household appliances.
