Best Generator Transfer Switch Kits for Winter Outages
A portable generator only helps in a winter outage if you can get its power to the things that matter, like the furnace blower, well pump, sump pump, and refrigerator. Running extension cords through a cracked window does not reach hard wired loads.
A manual transfer switch or interlock kit lets you plug the generator into one inlet outside and power selected household circuits safely. It also prevents backfeeding the utility lines, which can injure line workers.
Below are well known kits from established electrical brands. Every one should be installed by a licensed electrician and permitted where your town requires it.
Best Overall: Reliance Controls 31406CRK Transfer Switch Kit
Reliance Controls is the name most electricians reach for with portable generator switches. The 31406CRK is a six circuit, 30 amp kit that comes with the switch panel, a power inlet box, and a cord.
Each circuit has its own Line, Off, and Gen toggle plus wattmeters, so you can see how much load the generator is carrying and shift circuits around.
It suits generators up to about 7,500 running watts and covers the essentials for most homes.
Reliance Controls 31406CRK Pro/Tran 30 Amp 6 Circuit Transfer Switch Kit
Check price on Amazon
1,000+ reviews
A six circuit 30 amp manual transfer switch kit with inlet box and generator cord.
Shop on Amazon →Best for Larger Generators: Reliance Controls 31410CRK
If you own a bigger generator with a 30 amp twist lock outlet and want more circuits covered, the ten circuit 31410CRK gives you room for a well pump, furnace, fridge, freezer, and several lighting circuits.
It uses the same proven toggle and wattmeter design as the six circuit model.
More circuits does not mean more power, so plan loads around your generator's running watts.
Reliance Controls 31410CRK Pro/Tran 30 Amp 10 Circuit Transfer Switch Kit
Check price on Amazon
1,000+ reviews
A ten circuit 30 amp manual transfer switch kit for larger portable generators.
Shop on Amazon →Tips for a Safe Generator Hookup
- Hire a licensed electrician. Transfer switches tie into your main panel, and many towns require a permit and inspection.
- Match the amperage. Use a 30 amp kit with a 30 amp L14-30 outlet, or a 50 amp kit with a larger generator.
- List your must run circuits. Furnace, well pump, sump pump, and fridge come first. Add up their running watts before choosing circuits.
- Keep the generator outside. Run it at least 20 feet from the house with the exhaust pointed away, and use a CO alarm indoors.
Best Prewired Option: Connecticut Electric EmerGen Switch
Connecticut Electric's EmerGen switches come prewired with a flexible conduit whip, which can shorten installation time next to the main panel.
The kits pair a load center style switch with standard breakers, so the circuits stay protected when running on generator power.
It is a good alternative when the Reliance kit is out of stock or when your electrician prefers breaker style switching.
Connecticut Electric EmerGen 30 Amp Generator Transfer Switch Kit
Check price on Amazon
1,000+ reviews
A prewired manual transfer switch kit with breaker protected circuits for portable generators.
Shop on Amazon →Must Have Add On: Generator Power Cord
You will need a heavy gauge cord that matches your generator's outlet and your inlet box. A 30 amp, four prong L14-30 cord is the most common setup.
Buy a length that lets the generator sit at least 20 feet from doors and windows to keep carbon monoxide out of the house.
Look for a cold rated jacket that stays flexible in winter.
Champion Power Equipment 25 Foot 30 Amp L14-30 Generator Extension Cord
Check price on Amazon
1,000+ reviews
A 25 foot 30 amp four prong generator cord that connects a portable generator to a power inlet box.
Shop on Amazon →Frequently Asked Questions
Do I need a transfer switch for a portable generator?
You need one, or a code approved interlock, to power hard wired circuits like a furnace or well pump. It also prevents dangerous backfeeding.
Can I install a transfer switch myself?
Most areas require a licensed electrician and a permit, and it is the safest route because the work happens inside the main panel.
What size transfer switch do I need?
Match it to your generator's largest outlet. Most 5,000 to 7,500 watt generators use a 30 amp switch.
Will a portable generator run my furnace?
Most gas or oil furnace blowers need well under 1,000 watts, so a mid size generator through a transfer switch can run one easily.