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HVAC Interview Guide

What’s Hard to Evaluate in an HVAC Interview

Anyone can replace a part. The real skill is diagnosing why the part failed, and whether the candidate handles refrigerant (a federally regulated substance) the right way every time, not just when someone's watching.

Print this page for a combined worksheet with this trade’s questions plus the full 30-minute framework: notes lines and a rating scale after every question, ready to fill out by hand during the interview. Use your browser’s print function (Ctrl/Cmd+P) to generate it.

Technical Competency Questions

Walk me through how you'd diagnose a system that's low on cooling but not throwing an obvious fault code.

Tests real diagnostic sequence (checking superheat/subcooling, airflow, refrigerant charge), the core competency area EPA Section 608 and NATE both build toward, versus guess-and-replace.

Tell me about a time you recovered refrigerant from a system. What steps did you take and why?

This is a direct, EPA-regulated procedure with real legal weight (Clean Air Act Section 608). A vague or improvised answer here is disqualifying, not just a yellow flag.

Describe a callback where the original diagnosis was wrong. What did you find the second time?

Nobody's perfect; what matters is whether they can walk through re-diagnosing rather than deflecting blame to the equipment or the previous tech.

Red Flags

HVAC Interview Worksheet

Candidate name: Date:

Work History (5 min)

Walk me through your work history: what you did, what you were responsible for, and what tools or systems you used.

Notes:

Rate interviewer response 1–10, 10 being the best12345678910

Technical Competency (10 min) -- Question 1 of 3

Walk me through how you'd diagnose a system that's low on cooling but not throwing an obvious fault code.

Notes:

Rate interviewer response 1–10, 10 being the best12345678910

Technical Competency (10 min) -- Question 2 of 3

Tell me about a time you recovered refrigerant from a system. What steps did you take and why?

Notes:

Rate interviewer response 1–10, 10 being the best12345678910

Technical Competency (10 min) -- Question 3 of 3

Describe a callback where the original diagnosis was wrong. What did you find the second time?

Notes:

Rate interviewer response 1–10, 10 being the best12345678910

Safety (5 min)

Tell me about a specific time you stopped or changed a job because of a safety concern.

Notes:

Rate interviewer response 1–10, 10 being the best12345678910

Reliability (5 min)

Tell me about a specific mistake you made on the job and what you did afterward.

Notes:

Rate interviewer response 1–10, 10 being the best12345678910

Red Flags -- check any that apply

Candidate Questions (5 min)

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