Why backup power fails when you need it
Standby generators rely on a charged battery, a working transfer switch and correct wiring between the utility, generator and panel. A weak battery or failed transfer switch is a common reason a generator runs but the house stays dark.
Other issues show up under load: circuits that pull more than the generator can supply, motor loads like well pumps with high starting current, or loose connections that heat up. Regular exercise and maintenance catch many of these before a storm.
What the work typically involves
Review symptoms and codes
Check controller messages, recent outages and what failed.
Test transfer operation
Verify utility sensing, transfer switch function and connections.
Check load and wiring
Inspect breakers, conductors and load management.
Repair and retest
Correct the fault and simulate an outage.
Common reasons homeowners call
- Generator failed during the last storm
- Transfer switch stuck on utility or generator
- Generator overloads when the AC starts
- Portable inlet or interlock damaged
- New panel installed without reconnecting the generator correctly
Warning signs
- Generator runs but the house has no power
- Clicking or chattering transfer switch
- Burning smell at the transfer switch
- Generator shuts down under load
- Lights surging while on generator power
Safety considerations
Two power sources, double the hazard. Generator systems can energize wiring even when the utility is out. Don't open transfer switches or generator panels, and never bypass the transfer switch to get power back.
What an electrician will check
- Transfer switch contacts and controls
- Generator output breaker and conductors
- Battery and charger
- Load management modules
- Grounding and bonding configuration
Related electrical problems
Related residential services
Generator Installation
Standby and portable generator hookups with transfer switches or interlocks for safe backup power.
Whole Home Generator
Permanently installed standby generators sized to power your entire home automatically during outages.
Electrical Troubleshooting
Systematic testing to find the cause of intermittent power loss, tripping, flickering and other electrical faults that aren't obvious.
Surge Protection
Whole-house surge protectors at the panel plus point-of-use protection for electronics and appliances.
Frequently asked questions
Often the transfer switch didn't transfer, a generator breaker tripped or a control connection failed. Transfer testing identifies which.
Most standby units run a short automatic exercise cycle on a schedule. Check your owner's manual for the recommended interval and maintenance.
Electrical troubleshooting of transfer equipment and wiring applies across brands. Engine or warranty work may need an authorized dealer.