Standby Generator Installation in New Hampshire: What to Expect
A standby generator is a permanently installed backup power system that starts automatically within seconds of a utility outage. For New Hampshire homes where ice storms, wind events, and snow can knock out power for days at a time, a properly installed standby generator keeps the heat running, the well pump pumping, the refrigerator cold, and the basement dry.
At A.J. LeBlanc Heating, our licensed electricians and gas fitters install Generac and Kohler standby generators across Manchester, Bedford, Concord, Nashua, Salem, Auburn, and the surrounding communities. Here is what a complete, code-compliant installation looks like and why the details matter.
Sizing the generator to your home
Before any equipment is ordered, we walk through what you actually want to run during an outage:
- Heating system (boiler, furnace, heat pump)
- Well pump or septic pump
- Refrigerator and freezer
- Sump pump
- Lighting and outlets
- Optionally: air conditioning, range, electric water heater, EV charger
For an average NH home with essential loads, a 14 kW to 18 kW unit is typically sufficient. Larger homes or homes wanting full whole-house coverage (including central AC and electric range) usually step up to 22 kW or 24 kW. Going through the load list carefully prevents both undersizing (the generator can't handle the actual demand) and oversizing (you paid for capacity you'll never use).
Choosing a fuel source
Standby generators in NH run on either natural gas or propane:
- Natural gas: ideal where available. The utility supplies fuel continuously, so the generator can run indefinitely. Available in much of Manchester, Bedford, Nashua, and parts of Concord.
- Propane: the most common option in NH. Fuel comes from an on-site tank. A standard 500 to 1,000 gallon propane tank provides several days of runtime depending on load.
Gas piping is part of the installation. We handle the fuel-side work end-to-end, including permits.
What a complete installation includes
When we install a standby generator, you receive:
- A custom concrete pad sized and leveled to the unit's footprint, with proper drainage
- Professional electrical installation, including the automatic transfer switch (ATS) wired to your main panel
- Professional gas piping installation from the meter or tank to the generator, properly sized for the unit's fuel demand
- All electrical and gas permits pulled with your municipality
- Inspections coordinated with the building department
- Initial startup, configuration, and load testing to verify the system actually works under load
- Owner orientation covering the weekly self-test schedule, what error codes mean, and when to call for service
Cutting corners on any of the above is a common reason a generator either fails inspection or fails to start when you actually need it.
Why a transfer switch matters
The automatic transfer switch (ATS) is the brain that detects an outage, signals the generator to start, and safely disconnects the home from the utility before energizing it from the generator. A properly installed ATS:
- Protects utility workers from back-feed
- Prevents damage to the generator when grid power restores
- Sequences large loads to avoid overloading the unit on startup
Generators connected through anything other than a proper transfer switch (back-feeding through a dryer outlet, for example) are dangerous and illegal in NH.
Annual service is not optional
A standby generator that has not been serviced will likely fail when you need it. Annual service typically includes:
- Oil and filter change
- Air filter inspection or replacement
- Spark plug inspection or replacement
- Battery testing
- Load testing the unit at full capacity
- Verifying the weekly self-test schedule
- Reviewing any fault codes from the prior year
Manufacturers require documented annual service to maintain warranty coverage. Most modern units include cellular monitoring that notifies us (and you) when service is due or when faults occur.
Schedule a generator consultation
If your New Hampshire home is on a long utility loop, has a well, has sump pumps in a finished basement, or just leaves your family in the dark every time a winter storm rolls through, a standby generator is worth a conversation. Contact A.J. LeBlanc Heating for a sizing consultation and free estimate. Serving NH families since 1928.
Frequently Asked Questions
How big a generator do I need for my home?
Proper sizing starts with a load calculation by your installer. Typical NH whole-house standby units run 11 kW to 26 kW depending on the home's actual loads, and a smaller essential-circuits system is a valid lower-cost option if you only need to cover the basics like heat, the well pump, the refrigerator, and the sump pump.
How long can a standby generator run?
On natural gas, indefinitely (the utility keeps it fueled). On propane, several days from a typical 500 to 1,000 gallon tank at typical load. Runtime under heavy load is shorter.
Does a standby generator power the whole house automatically?
Yes, with a properly sized unit and an automatic transfer switch. The system detects an outage and restores power within seconds, with no homeowner intervention.
How loud is a standby generator?
Modern Generac and Kohler units are around 65 to 70 decibels at full load, similar to a window AC unit. They run a brief weekly self-test (typically 5 to 12 minutes) at a programmed time.
Are permits required to install a generator in New Hampshire?
Yes. Both electrical and gas (or propane) permits are required, along with municipal inspections. We handle all permitting as part of a complete installation.