What You'll Learn

• How to access the Diagnostics screen from the bottom navigation bar
• What pass/fail color indicators mean for each subsystem
• How to distinguish measurement-based subsystems from subjective (visual-only) subsystems
• What stability indicators are and why readings must stabilize before you trust the results
• How to tap into any subsystem for measurement details, targets, and explanations
• What the Vitals Score (0-100) represents and when it applies
• When and why a technician would override a pass/fail result

What You'll Need

• Device: iPhone (iOS 15+) or Android phone (Android 10+) with measureQuick installed
• Account: Logged in with an active measureQuick account
• Context: A test in progress or a completed test with diagnostic results (or Demo Mode enabled)
• Knowledge: Familiarity with the workflow UI and bottom navigation bar (see Workflow UI Navigation)
• Time: 10 minutes to read; 15-20 minutes to walk through with a live or demo test

Step-by-Step Guide

Step 1: Access the Diagnostics Screen

During or after a test, tap Diagnostics in the bottom navigation bar. This screen appears once the app has enough measurement data to evaluate system performance.

Gauges view showing bottom navigation bar with Home, Grid, Gauges, System, and Toolbox tabs

If the Diagnostics tab is grayed out, the test does not yet have sufficient probe data. Connect your smart tools and wait for live readings before proceeding.

Tip: You can also reach the Diagnostics screen by opening a saved project and tapping into a completed test.

Step 2: Read the Subsystem Pass/Fail Indicators

The Diagnostics screen displays a list of subsystems. Each one has a color-coded indicator showing its status.

Diagnostics screen showing System Status, Major Potential Faults, and Minor Faults sections with flag indicators

The color codes are:

The subsystems fall into two categories:

Measurement-based subsystems rely on live probe data:

• Refrigerant Charge
• Airflow
• Electrical
• Capacity
• Venting (combustion systems)

These subsystems produce objective, instrument-driven pass/fail results.

Subjective subsystems rely on technician visual inspection:

• Condensate
• Outdoor Visual
• Indoor Visual
• Air Filtration

These four subsystems default to a result based on general conditions, but technicians override them roughly 95% of the time based on what they observe on site. Report and interpret these separately from measurement-based subsystems.

Step 3: Check Stability Before Trusting Results

Stability means the live readings have settled within an acceptable variance. The Diagnostics screen displays a stability indicator for the active measurements.

What "stable" means: The system's temperatures and pressures are no longer fluctuating significantly. Small variations are normal; the app looks for readings that hold within a narrow band over a sustained period.

Why it matters: Unstable readings produce unreliable diagnostics. If you evaluate a system before it stabilizes, the pass/fail results may not reflect actual performance. A refrigerant charge reading taken two minutes after startup will differ from one taken after the system reaches steady state.

How long to wait: Allow 10-15 minutes after system startup for readings to stabilize. Variable-speed and multi-stage systems may take longer. Do not finalize your diagnostic evaluation until the stability indicator confirms the readings are settled. The app's trending timer (configurable in Settings > Advanced Settings > Trending Time Limit; default: 2 minutes) tracks measurement changes over time to determine when the system has reached steady state. Available durations are 2 minutes, 10 minutes, 30 minutes, 1 hour, and 2 hours.

Tip: If readings remain unstable after 20 minutes, that itself may indicate a system problem, such as a restriction, low charge, or intermittent electrical fault.

Step 4: Tap into Subsystem Details

Tap any subsystem row to open its detail view. The detail modal shows:

• Current measured value - the live or recorded reading from your probes
• Design target - the expected value based on the system profile you configured
• Acceptable range - the tolerance band around the target
• Explanation - a plain-language description of what the measurement means and why it passed or failed

TESP measurement detail showing current value, target, ideal range, and HVAC School link

This is where you confirm whether a red or yellow flag is justified. The detail view gives you the numbers behind the indicator so you can make an informed decision.

mQ Assist: The Diagnostics screen also provides access to mQ Assist, a context-aware AI assistant trained specifically for HVAC diagnostics. mQ Assist can provide guidance based on your current readings and diagnostic results. It is available on all subscription tiers.

Step 5: Understand the Vitals Score

The Diagnostics screen displays a Vitals Score at the top or in a prominent summary area. This is a 0-100 composite score that reflects overall system health.

Key facts about the Vitals Score:

• Scale: 0 (worst) to 100 (best), with corresponding A-F letter grades.
• Color coding: Green (healthy), Yellow (concerning), Red (critical).
• Probe requirement: The score requires at least 9 physical probe channels for cooling and heating tests, or at least 7 physical probe channels for gas furnace tests. If fewer probes are connected, the Vitals Score will not calculate. "Physical" means actual instruments; calculated channels and weather data do not count.
• Age-adjusted score: The app also calculates an age-adjusted Vitals Score that accounts for equipment age. Older equipment is expected to perform slightly below a new unit. The age-adjusted score reflects this expectation.
• What it communicates: A high Vitals Score means the system is performing near its rated specifications across all measured subsystems. A low score means one or more subsystems are significantly outside acceptable ranges. The score removes the technician's personal opinion from the diagnosis by basing the result entirely on measured data.
• Report availability: The Vitals Score appears in the HVAC Vitals Report (Premier subscription required), which is a consumer-facing PDF with A-F grading and color-coded status indicators.

The Vitals Score is useful for customer-facing reports. It gives homeowners a single number that summarizes system health without requiring them to interpret individual subsystem results. It also supports replacement vs. repair conversations by providing objective, measurement-based evidence.

AI Diagnostics Summary (New in 3.6)

measureQuick 3.6 adds an AI-generated diagnostics summary that analyzes all measurement data in the current test and produces a structured report with four parts:

1. System Analysis - what the data shows (e.g., low evaporator load, possible loose TXV bulb, system overcharged)
2. What It Means - plain-language explanation of the findings and their significance
3. Recommended Actions - specific next steps for the technician (e.g., check bulb mounting, check airflow restrictions, verify profile accuracy)
4. Homeowner Explanation - a simplified summary suitable for sharing with the customer

The AI diagnostics summary uses the actual live measurements from your connected probes, not manual input. It updates as your data changes. AI diagnostic notes can be stored and viewed later in the service history timeline.

In the mQ+ interface, you can also interact with the AI via the mic button in the Navigation Drawer at the bottom of the screen. This opens AI Assist, which responds to voice commands and text queries about the current test data. AI Assist is restricted to measureQuick diagnostic tasks and will not answer off-topic questions.

For the full AI Assist guide, see AI Assist.

Step 6: Override a Pass/Fail Result (When Necessary)

In some cases, you may need to override a subsystem's pass/fail result. The app allows this for any subsystem.

To override a result, tap the subsystem to open its detail view, then look for the override option. Toggling the override changes the result from its calculated value to the opposite (Pass to Fail, or Fail to Pass).

Diagnostics detail view showing fault description, condition, symptoms, and resolution steps

When you override a result, the system records that pf_*_override = 1 for that subsystem. The reported pass/fail rates in measureQuick are post-override values, meaning they reflect the technician's final judgment, not the raw calculated result.

When to override:

• The system has a known condition that explains an out-of-range reading (for example, a refrigerant charge flag on a system you just charged that has not yet stabilized).
• A subjective subsystem's default result does not match your on-site observation.
• You have additional context the app does not have (for example, a manufacturer specification that differs from the app's default target).

When not to override:

• Do not override to make a report "look better." The diagnostic results are there to document actual system condition.
• Do not override a measurement-based subsystem without a clear technical reason.

Video Walkthrough

These videos demonstrate the Diagnostics screen and how to interpret results:

• measureQuick Diagnostics: Behind The Curtain: (4,695 views, 9:22) - Explains how measureQuick's diagnostic engine evaluates system performance

• HVAC Vitals Score in just 20 minutes: (2,153 views, 1:50) - Demonstrates the workflow process leading to a Vitals Score, covering the diagnostic results that feed into the score

• The Power of The HVAC Vitals Score: (475 views, 0:59) - Overview of how the Vitals Score communicates system health to homeowners

• Introduction to measureQuick: (13,518 views, 1:30:48) - Comprehensive walkthrough including diagnostic screens, Vitals Score, and result interpretation

Tips & Common Issues

Readings are unstable after 15 minutes

Check that the system is running in a single, consistent mode. If the system is short-cycling, has a faulty contactor, or is in defrost mode (heat pumps), readings will not stabilize. Address the operational issue first, then re-evaluate.

Vitals Score is not showing

The Vitals Score requires a minimum number of physical probe channels: 9 for cooling and heating, 7 for gas furnace. If fewer probes are connected, the score will not appear. Connect additional probes or verify that your connected probes are reporting live data (not calculated or weather-derived).

Gray indicators on subsystems you expected to measure

Gray means the app has no data for that subsystem. Confirm that the relevant probes are paired and transmitting. Check the probe connection indicators on the measurement screen (see Test Mode Navigation). A probe that is paired but not placed on the correct measurement point will not populate the subsystem.

Subjective subsystem results seem wrong

Condensate, outdoor visual, indoor visual, and air filtration are based on visual inspection defaults. These almost always need a technician override. Tap the subsystem, review the default, and override it to match what you actually observed on site.

Should I override a failing refrigerant charge result?

Only if you have a specific technical reason. Common valid reasons: the system was just charged and has not stabilized, or you are using a refrigerant type that the profile does not fully support. If the system has been running for 15+ minutes and the charge reading is still failing, that is likely a real finding. Document it rather than overriding it.

Yellow vs red: how serious is a yellow flag?

Yellow indicates a minor fault - the reading is outside the ideal range but within a broader tolerance. It warrants attention but does not necessarily mean the system is failing. Red indicates the measurement is outside the acceptable range entirely and represents a major fault that should be addressed. Use the detail view to see exactly how far the reading is from the target.

Using diagnostics to communicate with homeowners

"It's just like having the senior tech right there beside you telling you why your superheat is too high." - Aaron Gregg, Service Manager, Jacob's Ladder Heating and Cooling

The Diagnostics screen gives technicians objective data to share with customers. Rather than saying "I think there's a problem," technicians can show the red/green indicators and the Vitals Score. Aaron Gregg reports that customers respond well to the visual format: "Customers have told me multiple times, I've never had a company show me that type of thing before."

Understanding fault escalation

The Diagnostics screen shows minor faults with numbers (2, 3, 2, etc.) next to them. These numbers indicate how many contributing factors combine to create each fault. When multiple minor faults share underlying causes, the app escalates them to a higher-level problem. Focus on the escalated faults first, as fixing the root cause often resolves multiple minor faults at once.

Reference Material

Gauge Screen Exercise

Gauge Screen Exercise - Page 1

Gauge Screen Exercise - Page 2

Related Articles

Prerequisites:

• Workflow UI Navigation

Follow-up articles:

• Reading Diagnostic Flags
• Fault Types: Minor vs Major
• mQ Assist (AI Diagnostics)
• Target Zones
• AI Assist (Voice/Text Diagnostics)
• System Stabilization
• Interface Mode Selection (mQ Classic vs mQ+)

Need Help?

Contact measureQuick support: support@measurequick.com