Yes, and it happens more often than most homeowners expect. When only part of your house loses power — one room, one floor, or one side of the home — while everything else works normally, that’s a specific kind of electrical problem with a defined set of likely causes. It’s also a situation that warrants a licensed electrician’s attention, because some causes are minor while others signal a serious safety issue.

The Most Common Reasons Part of a House Loses Power

A tripped circuit breaker is the most frequent culprit and the easiest to resolve. Each breaker in your panel controls a specific circuit — a section of outlets, a room’s lighting, or a dedicated appliance circuit. When a breaker trips, it cuts power to everything on that circuit while the rest of the panel continues operating normally. Check your panel for a breaker that’s in the middle position (not fully on, not fully off) and reset it by switching it fully off first, then back on.

A tripped GFCI outlet is another common culprit. In Colorado homes, GFCI outlets are required in bathrooms, kitchens, garages, outdoor areas, and anywhere near water. What’s not always obvious is that a single GFCI outlet often protects multiple downstream outlets on the same circuit. If a bathroom outlet, a kitchen outlet near the sink, or a garage outlet trips, it may kill power to a group of seemingly unrelated outlets elsewhere. Find the GFCI outlet with the test/reset buttons and press reset.

When the Problem Is More Serious: A Lost Leg

A more serious scenario occurs when an entire “leg” of your electrical service fails. Residential service in the US is 240V, delivered as two 120V legs. If one leg fails — due to a loose connection at the weatherhead, a problem at the transformer, or a damaged service entrance conductor — you’ll lose power to roughly half your home. Everything on breakers served by that leg goes dark, while 240V appliances like your dryer, electric range, or central AC may stop working entirely even though their breakers appear on.

This is a utility and/or service entrance issue that requires both the utility company and a licensed electrician to assess. Done can inspect the service entrance, weatherhead, and meter base connections on your side of the meter. Never attempt to inspect or work on service entrance conductors yourself — these are always energized and present a lethal shock hazard.

Other Causes Done Investigates

  • Loose wiring connections: A loose wire at an outlet, junction box, or panel can cause intermittent power loss on a circuit — sometimes correlated with vibration, temperature changes, or load
  • Failing breaker: A breaker that appears on but isn’t conducting properly — common in panels that are 20–30+ years old — can cause a circuit to appear dead even when the breaker isn’t tripped
  • Aluminum wiring issues: Some Denver-area homes built in the 1960s and 1970s have aluminum branch circuit wiring that can create oxidation and connection problems over time
  • Overloaded panel: An older panel that’s been maxed out can have breakers that don’t hold reliably under load

What to Do Right Now

If you’ve checked the panel and reset any tripped breakers or GFCI outlets and still have partial power loss, call Done. Don’t repeatedly reset a breaker that keeps tripping — that’s a signal of an overload or a fault condition, and continuing to reset it can damage wiring or create a fire hazard. Partial power loss accompanied by a burning smell, scorch marks, or sparking anywhere in the home is an emergency that warrants calling an electrician immediately.

Preventing Future Electrical Problems

Older panels — particularly Federal Pacific and Zinsco panels found in some Denver-area homes from the 1960s–1980s — have documented reliability and safety issues. If your home has one of these panels or a panel that’s showing signs of age, Done can evaluate whether an upgrade is warranted. Arc fault circuit interrupter (AFCI) breakers and whole-home surge protection are additional layers of safety worth considering, especially in homes with older wiring.

Done’s licensed electricians diagnose panel and circuit issues throughout the Denver metro. Visit our panels and wiring page for more on what we handle, or contact emergency electrical service if you need immediate help. For ongoing peace of mind, explore electrical safety upgrades that add arc fault and surge protection to aging circuits.