What happens if you fail a HERS test?

By Roman Leonelli, CEO & Certified HERS / ECC Rater — CHEERS Rater #RCN13486. Published June 10, 2026.

First, the good news

A failed HERS test is a punch-list item, not a code violation. Nothing gets filed with the city, nobody gets fined, and no permanent record of the failure exists anywhere. The CF3R — the Certificate of Verification that a HERS / ECC rater registers when measures pass — only ever gets registered with a passing result. A failure just means: fix the issue, retest, then register.

Quick terminology: HERS is the Home Energy Rating System, the field-verification program under Title 24 — California's Building Energy Efficiency Standards, Title 24, Part 6 of the California Code of Regulations. As of January 1, 2026 the California Energy Commission renamed the compliance side of the program ECC (Energy Code Compliance), so you'll see "HERS rater" and "ECC rater" used interchangeably — same tests, same registries, per the CEC's Energy Code Compliance Program.

The three most common ways a HERS test fails

1. Duct leakage over the target

The rater pressurizes the duct system with a calibrated fan and measures how much air escapes, expressed as a percentage of system airflow. Brand-new duct systems typically have to come in at or under 5% total leakage; alterations to existing systems typically get 15%, with fallback options when old ducts can't reasonably get there. Your project's registered CF1R (Certificate of Compliance) sets the exact target.

What actually pushes a system over: unsealed register boots, loose plenum and takeoff connections, disconnected runs in the attic, and cloth duct tape doing a job only mastic can do. This is the most common failure we see — and the most fixable. More on the test itself on our duct leakage testing page.

2. Refrigerant charge out of range

Air conditioners and heat pumps in the warmer climate zones — and, for permits filed under the 2025 Energy Code, heat pumps in all 16 climate zones per the CEC's What's New for 2025 fact sheet — need refrigerant charge verification. Systems fail when they're overcharged or undercharged for the line-set length and metering device. One catch worth knowing: charge can't be verified until airflow passes, because charge readings depend on airflow across the coil. A clogged filter can sink a refrigerant test.

3. Airflow or fan efficacy below the mark

Ducted cooling systems have to deliver at least 350 CFM of airflow per ton of cooling, and the blower has to do it without exceeding the fan-watt limit on the CF1R. Failures here are almost never the equipment — they're undersized or restrictive return ducts, crushed or kinked flex duct, dirty filters, and restrictive filter grilles. Airflow failures often surface a comfort problem the homeowner would have lived with for years.

What can be fixed while the rater is still there

If your HVAC contractor is on site when we test, most failures die the same hour they're found. Same-visit fixes we see constantly:

• Mastic-sealing accessible connections. Boots, plenums, and takeoffs get sealed, and the duct test runs again 20 minutes later.
• Reconnecting a pulled run. A duct knocked loose in the attic is found, reattached, sealed, and retested on the spot.
• Opening dampers and registers, swapping filters. The cheapest airflow fixes there are — and they're behind a surprising share of failures.
• Adjusting refrigerant charge. The installing tech adds or recovers refrigerant while we're there, and we re-verify immediately.

One thing we can't do: fix it ourselves. HERS / ECC raters are independent third parties by regulation — the same company can't install, correct, and then verify its own work. What we can do is show your contractor exactly what failed, where, and by how much, then stay and retest once it's corrected.

Retest economics

When a fix can't happen on the spot, a return trip costs money — how much depends on the rater. Published market rates in California: one Burbank firm publishes re-testing at $125 per hour, and one Northern California rater publishes $50 per additional same-visit test and $85 per extra site trip. Most Los Angeles and Orange County field raters don't publish retest pricing at all.

The bigger cost is usually the schedule: a failed duct test can hold up drywall, a final inspection, or an escrow date. That's why the cheapest retest is the one that happens the same visit — have the installing contractor there when the rater tests. ERE quotes retests upfront as part of a fixed quote, so there's no surprise invoice — request a quote or call (310) 807-4800. For what first-visit testing runs across the market, see our HERS test cost guide.

How ERE handles the documentation

A failed measure never touches the registry. Here's our process when something doesn't pass:

• We document the failure on site. What failed, where, and the measured numbers — with photos — so your contractor isn't guessing.
• You get a plain-language punch list the same day. Not a code citation — an exact fix list, like "seal the supply plenum takeoffs; the system measured 11.2% against a 5% target."
• We retest — same visit when the fix happens while we're there. Otherwise we schedule the return trip around your drywall or inspection date.
• The passing CF3R is registered with CHEERS. CHEERS is the CEC-approved data registry ERE uses — CalCERTS shut down its HERS registry in September 2024 — and the registered CF3R is what your building inspector checks at final.

Same-day results is the standard, not the exception: you and your contractor know whether the project passed before we leave the driveway, and the paperwork follows the same day. If the failed test is the last thing standing between you and a permit final, our final inspection and closeout service carries it the rest of the way. And if you want the full compliance sequence from permit to sign-off, read our Title 24 compliance checklist.

How to pass the first time

• Have the installing contractor on site for the test. The single highest-leverage move — most failures become same-visit fixes.
• Seal accessible duct connections with mastic before we arrive. Boots, plenums, takeoffs — not cloth tape.
• Fresh filter in, every register open, power on. Three free points of airflow.
• Weigh in refrigerant per the manufacturer's line-set spec. Don't leave charge at the factory pre-fill on long line sets.
• Confirm the installed equipment matches the CF1R and the CF2R is registered. Paperwork mismatches stall verification as surely as failed tests do. See what HERS / ECC testing covers.

Frequently asked

Does a failed HERS test get reported to the building department?

No. A failed test is not filed anywhere — the registry only ever carries the passing result. We document what failed for you and your contractor, the fix gets made, and the building department only sees the registered passing CF3R. A failed HERS test is a punch-list item, not a code violation.

What is the most common reason homes fail a HERS test?

Duct leakage. Unsealed boots, loose plenum connections, and cloth tape instead of mastic push leakage over the target — typically 5% of system airflow for brand-new duct systems and 15% for alterations to existing systems. The fix is almost always sealing, and it's often done the same visit.

Can the HERS rater fix the problem and pass me?

No. HERS / ECC raters are required to be independent third parties — we can't seal your ducts or adjust your refrigerant charge and then verify our own work. What we can do is show your contractor exactly what failed and where, wait while it's corrected, and retest on the spot.

How much does a HERS retest cost?

Published California market rates run from about $50 per additional test and $85 per return trip to $125 per hour for re-testing, depending on the rater. ERE quotes retests upfront as part of a fixed quote — call (310) 807-4800 and we'll tell you exactly how a retest would be handled before anyone books.

How fast can I retest after a fix?

If the fix happens while we're on site, we retest the same visit at no schedule cost. If a return trip is needed, we serve LA, Orange County, and the Inland Empire and can usually get back out within days — and you get same-day results either way.