After investing in a new HVAC system or ductwork upgrade, you’re probably expecting to enjoy better comfort and energy savings. But before you can call the project complete in California, your system has to pass HERS testing—and many homeowners are shocked to learn that failure is more common than they think.
California HERS testing is required to verify your HVAC system meets strict energy performance standards under Title 24. Failures delay final inspections, trigger rework, and cost more money. In this blog, we’ll break down the top reasons systems fail, how to avoid them, and how working with the right contractor can save you time and frustration.
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TLDR – Quick Guide
- Common causes of HERS failures:
- Leaky ductwork
- Improper refrigerant charge
- Airflow levels below code
- Incorrect or missing documentation
- Inaccessible system components
- How to avoid costly re-tests:
- Work with contractors who understand HERS compliance
- Conduct a pre-test system review
- Ensure accurate CF1R and CF2R forms are submitted
- Schedule HERS early in the project timeline
- Keep all registers, thermostats, and units accessible for the rater
Detailed Breakdown: Why California HERS Testing Often Fails
1. Duct Leakage Is the #1 Cause of Failed HERS Tests
HERS raters measure how much air escapes from your duct system, and most failures come from air leakage beyond acceptable limits. Even small cracks in your ductwork, often hidden in crawlspaces or attics, can sabotage your results.
California requires duct leakage to remain under 6% of system airflow in most homes. If your contractor skipped or rushed sealing during installation, your system could fail before it’s even inspected.
2. Incorrect Refrigerant Charge or Low Airflow
HERS inspections also check refrigerant charge levels (for systems that use refrigerant) and airflow performance. Improper charging or undersized duct systems can cause airflow to fall below required thresholds.
This isn’t just a compliance issue—it affects efficiency, comfort, and the long-term health of your system. A system that passes HERS is also one that works better year-round.
3. Missing or Incomplete Compliance Forms
Before your HERS inspection, your contractor must submit CF1R and CF2R forms through the state’s HERS registry. These forms document your system’s specs and installation details.
Failure to submit them—or submitting inaccurate versions—means the rater can’t perform the inspection, resulting in a wasted appointment and rescheduling fees. Brewer Heating & Air Conditioning handles all documentation and submission in-house so you don’t miss a step.
4. Accessibility and Jobsite Conditions
If the HERS rater can’t access your equipment, vents, or registers, they can’t complete the inspection. Obstructed HVAC units, locked attics, or missing thermostats can all halt testing before it begins.
Homeowners often don’t realize that site prep is critical. You or your contractor should ensure the space is clean, powered, and ready to go before the rater arrives.
5. Choosing the Wrong Contractor
The most avoidable failure? Hiring a contractor who doesn’t understand California compliance. A great install isn’t enough—it must meet Title 24 requirements to legally pass inspection.
At Brewer Heating & Air Conditioning, we’ve built our installation and design process to meet and exceed HERS standards from the start. That means your system is prepped to pass—no surprises, no added costs.
Key Takeaways
- Most HERS testing failures in California stem from preventable issues like leaky ducts or missing paperwork.
- Re-tests cost time and money, and can delay your final HVAC inspection or occupancy.
- Working with a contractor experienced in Title 24 and HERS compliance is the easiest way to avoid failed tests.
- Duct sealing, proper refrigerant charge, and accurate documentation are essential for first-time passes.
- Brewer Heating & Air Conditioning ensures every system we install is designed to pass California HERS inspections without rework.
FAQs
What happens if I fail a HERS test?
If your system fails, the issue must be corrected before a retest can be scheduled. This often involves sealing ducts, adjusting refrigerant, or replacing documentation. The retest also comes with added costs and can delay your final inspection.
Can I skip HERS testing for my HVAC system?
No—California law requires HERS testing for most HVAC installations and duct replacements under Title 24. Skipping this step can result in permit issues, fines, and non-compliance. It also voids opportunities for rebates or energy credits.
How can I prepare for a successful HERS inspection?
Ensure all HVAC components are accessible, and verify that your contractor has submitted the proper CF1R and CF2R forms. Choose a contractor that prioritizes duct sealing, airflow testing, and refrigerant accuracy. A pre-inspection review can also catch issues early.
How much does a HERS test cost in California?
Costs vary by region and complexity but generally range from $200–$500. Additional charges apply for re-tests or if multiple systems are being tested. Hiring a qualified HVAC contractor can reduce or eliminate the need for re-testing.
Does Brewer Heating & Air Conditioning handle HERS testing?
Yes, we coordinate all HERS inspections, submit required documentation, and ensure every system we install meets Title 24 standards. Our goal is to help you pass on the first try.Contact us to schedule a compliant HVAC installation today.