CIRCUIT/CHECK
(303) 555-0118
Safety inspection & testing · Denver & the Front Range

We measure it.Then we write it down.

Safety inspections, rental certificates and troubleshooting for residential and light commercial properties. Every reading logged, every repair priced before we touch it.

INSULATIONAUTO · HOLD
0.00
500 V d.c. · L+N to E

Turn the selector to see what we test. Drag it, tap a label, or use .

Insulation resistance

MODE 01 / 05
WHY

Finding tired cable

Sixty-year-old rubber insulation goes brittle and cracks at the bends. A 500 V test tells us how much of the circuit is still doing its job before it becomes a fire.

PASS

1 MΩ minimum

Anything under 2 MΩ gets investigated rather than signed off. We isolate circuit by circuit so you keep power everywhere else.

TIME

Around 3 hours

Typical three-bed semi with a ten-way board. We work room by room and put everything back where we found it.

WHY

The ground path

If a hot conductor touches metal, the ground is what carries the fault away. Continuity proves that path exists end to end, not just at the panel.

PASS

R1+R2 against design

We compare measured values to calculated maximums for the cable length and size. Out of range means a joint, not a guess.

FOUND

Borrowed neutrals

The classic 1970s upstairs-downstairs lighting botch. We find it on the meter and show you on the schedule where it lives.

WHY

Disconnection time

A GFCI has to open in under 25 ms at five times its rating. Slower than that and the protection is decorative.

PASS

Both polarities

We test at 0° and 180° and record the worst result, because that's the one that matters at 2am.

SWAP

AFCI/GFCI, one per circuit

If yours trips the whole house when the coffee maker sparks, we can split the panel so a fault takes out one circuit only.

WHY

Loop impedance

Ze at the origin, Zs at every point. It tells us whether the supply can actually push enough fault current to trip the protective device.

PASS

Below tabulated max

Adjusted for conductor temperature, not read straight off the chart. It's the difference between a pass and an honest pass.

NEXT

Service upgrades

Where the utility service drop is the limiting factor, we file it with your power company on your behalf and manage the appointment.

OUT

The certificate

A signed inspection report with a schedule of results, a panel directory, and photographs of anything flagged. Emailed as PDF within 48 hours.

OUT

A priced repair list

Separated into "must do to pass the report" and "worth doing while we're here". No line item without a number next to it.

OUT

Permit and sign-off

Permitted work filed with your city building department and inspected. You get the signed final inspection card for your records.

Your report came back with letters on it

Most people are handed an inspection report and told it "failed" with no explanation. Here's what each finding actually means for you.

Safety hazard. We make it safe before we leaveExposed live parts, a broken receptacle face, a range circuit tied into lighting. We kill it the same day and tell you what we've done in writing. You'll never get an H1 by email with no phone call.
0Inspections since 2011
0Landlords on annual plan
0Hrs to certificate
0Callbacks last year
CO
LIC.
61129
“Three quotes said 'full rewire'. Circuit Check tested it, found two dead circuits and a shared neutral, and fixed both for a tenth of the price.”
Property manager, 14 units, Capitol Hill

Book an inspection

Tell us the property and we'll come back the same business day with a fixed price and two dates. No survey fee, no "from" pricing.

EMERGENCY / NO POWER → 0113 000 0000 · 24 HR

Fixed price, inc. certificate$325