What You'll Learn

• How to use the Hold button in measureQuick to freeze measurement values at a point in time
• When to hold individual channels vs. all channels simultaneously
• How to manage indoor/outdoor transitions on split systems where Bluetooth range is limited
• What happens when a probe reads outside its expected range, and how mQ flags it
• How to reconnect and release held readings after moving between units
• Best practices for accuracy when using held measurements

What You'll Need

• Device: iPhone (iOS 15+) or Android phone/tablet (Android 10+) with measureQuick installed
• Probes: At least one Bluetooth probe paired and streaming data
• Active test: An open project or quick test with probes assigned to measurement channels
• Knowledge: Familiarity with the diagnostic screens and measurement layout (see Understanding Diagnostic Screens)
• Time: 5 minutes to read; practice during your next service call

Step-by-Step Guide

Step 1: Understand Why Hold Exists

On split HVAC systems, the indoor and outdoor units are physically separated. Bluetooth probes at the air handler may be 30-100+ feet from probes at the condenser. Depending on your probe manufacturer's Bluetooth range, you may not be able to receive signals from both sets of probes simultaneously.

The Hold feature solves this. It freezes the current measurement values on screen so you can walk to the other unit without losing the readings. The held values persist until you release them manually.

Hold is also useful for capturing a reading before conditions change. For example, you might hold a wet bulb reading before opening a panel that disrupts airflow, or hold a static pressure reading before removing the filter to measure pressure drop.

Step 2: Hold All Channels on a Page

The primary use case: freezing all readings on the Indoor Measurements or Outdoor Measurements page before walking to the other unit.

1. Navigate to the Indoor Measurements or Outdoor Measurements page in your active test.
2. Confirm all probes on this page are connected and displaying live values. Held readings are only as good as the last live value received.
3. Tap the Hold button in the top right corner of the measurement page.
4. All values on the page freeze. The display indicates that readings are held (typically a visual indicator or color change on the Hold button).
5. Walk to the other unit. The held values remain on screen even as Bluetooth connections drop.

What you see: The measurement values stop updating. If a probe disconnects during your walk, the held value remains. You will not see "---" or a blank field for held channels.

Indoor Measurements page with Hold active, showing frozen temperature and pressure values with the Hold indicator visible

Step 3: Release the Hold

When you return to the unit or finish your measurements at the other location:

1. Walk back within Bluetooth range of the probes.
2. Wait for the probes to reconnect. Depending on the manufacturer, reconnection takes 2-10 seconds.
3. Tap the Hold button again to release. The values update to live readings.
4. Verify the live readings are reasonable before saving a test snapshot. Conditions may have changed while you were at the other unit.

Tip: Do not save a test snapshot while readings are held unless you are confident the held values represent steady-state conditions. If the system was still stabilizing when you tapped Hold, the held values may not reflect actual operating performance.

Step 4: Hold Before Conditions Change

Beyond indoor/outdoor transitions, Hold is useful for capturing a point-in-time reading:

• Before opening a panel: Hold wet bulb and dry bulb readings before removing the air handler access panel. Opening the panel changes the airflow path and can shift temperature readings.
• Before removing a filter: Hold the total external static pressure reading, then remove the filter. The difference between the held reading and the new reading is the pressure drop across the filter.
• During a charge adjustment: Hold current superheat and subcooling values before adding or recovering refrigerant. After the adjustment, release Hold and compare.
• Quick snapshot of transient conditions: If the system is cycling or a defrost cycle is about to start, Hold captures the current state before conditions shift.

Step 5: Understand Out-of-Range Readings

measureQuick monitors each probe channel against expected ranges for the system type and test mode. When a reading falls outside the expected range, the app flags it.

How out-of-range detection works:

• Each measurement channel has an acceptable range based on the equipment profile, test type, and operating conditions. For example, suction line temperature on a cooling test is expected to be in a certain band relative to saturation temperature.
• If a probe reading falls outside this range, mQ displays a warning. The specific indicator depends on the app version, but it typically appears as a color change (yellow or red) on the measurement field or an alert message.
• Out-of-range readings are not automatically discarded. The app records the value and flags it for your review.

Common causes of out-of-range readings:

Tip: If a reading goes out of range while you have Hold active, the held value remains from before the range excursion. This is correct behavior. The Hold feature preserves the last stable reading.

Step 6: Reconnecting After a Hold

When probes disconnect due to range (not because Hold was tapped), the behavior differs from a manual Hold:

• Manual Hold (you tapped the button): Values freeze at the moment you tapped Hold. They remain frozen until you tap Hold again to release. Probes may disconnect and reconnect in the background, but the displayed values do not change until you release.
• Signal loss without Hold: If probes go out of range and you did not tap Hold, the app shows the last received value briefly, then displays "---" or a disconnected indicator. When the probe reconnects, live values resume.

Best practice: always tap Hold before walking away from a probe location. Do not rely on the app to retain stale values from a dropped connection. A manual Hold is explicit; a dropped connection is ambiguous.

Reconnection steps:

1. Return to within Bluetooth range of the probes.
2. The probes reconnect automatically in most cases. If they do not, open the Probe Manager and tap the probe to manually reconnect.
3. Release Hold.
4. Confirm all channels show live, updating values.
5. If a probe does not reconnect within 15 seconds, power-cycle the probe (off, wait 5 seconds, on).

Indoor/Outdoor Transition Workflow

This is the most common Hold scenario. Here is the complete sequence for a split system service call:

1. Deploy all probes at both the indoor and outdoor units.
2. Start your test and verify all probes are streaming data.
3. Let the system run for 10-15 minutes to reach steady state.
4. Stand near the indoor unit. Verify indoor readings (return air, supply air, static pressure) are stable.
5. Tap Hold on the Indoor Measurements page.
6. Walk to the outdoor unit. Indoor probes may disconnect, but held values remain.
7. At the outdoor unit, verify outdoor readings (suction line, liquid line, outdoor ambient, pressures) are live and stable.
8. Capture or save the test. The combination of held indoor values and live outdoor values gives you a complete picture.
9. If needed, walk back inside, release Hold, and verify indoor readings have not changed significantly.

Range considerations by probe manufacturer:

With extended-range probes like Fieldpiece JobLink, you may not need Hold at all on smaller homes. On larger homes or multi-story buildings, Hold is essential regardless of probe brand.

Video Walkthrough

• Probe placement and measurement with Hold context: (80 min, 13K views) - Complete commissioning walkthrough that demonstrates measurement capture techniques

• New System Commissioning: - Covers probe deployment and measurement capture on a new system installation

• Probe placement (dedicated): (7:43) - Covers both indoor and outdoor probe positions with discussion of range limitations

• Why all 9 probes matter: (1:42, 5.8K views) - Explains the channel requirements that make Hold necessary when you cannot cover all channels from one spot

Tips & Common Issues

I tapped Hold but one value shows "---"

That probe was already disconnected when you tapped Hold. Hold freezes the current displayed value. If a probe was out of range or disconnected at the moment you tapped Hold, there is no value to freeze. Reconnect the probe, verify the live reading, then tap Hold again.

Held values seem wrong after I release

Conditions changed while you were at the other unit. This is normal if the system was still stabilizing. Best practice: wait for steady state before using Hold. If the supply air temperature dropped 3F while you were at the condenser, the system was still settling.

How long can I keep readings held?

There is no time limit on Hold. However, the longer you hold, the less the held values represent current conditions. On a system at steady state, values should be stable for 15-20 minutes. If you hold for more than 5-10 minutes, verify conditions have not changed before saving.

Should I hold indoor or outdoor first?

Either approach works. Most technicians hold indoor readings first because the indoor unit is less exposed to changing conditions (outdoor ambient temperature, wind, sun load). But if the outdoor unit is harder to access or farther from where you park, hold outdoor first and walk inside.

The app shows a warning on a held value

Held values can still trigger range warnings. If the value was borderline when you held it, the app may flag it. Verify the reading is correct by releasing Hold, checking the live value, and re-holding if needed.

Related Articles

Prerequisites (complete these first):

• Understanding Diagnostic Screens
• Outdoor Probe Placement

Follow-up articles (next steps after this one):

• Capturing Measurements
• A/C Service Workflow

Related in the same domain:

• Indoor Probe Placement: Air Handler
• Heat Pump Heating Mode Probes (Hold is especially important in heating mode)

Related in other domains:

• Bluetooth Pairing Basics (range and connectivity fundamentals)
• Bluetooth Troubleshooting (reconnection issues)

Need Help?

If you get stuck or this article does not answer your question:

• Check the Related Articles section above
• Review the existing Zoho help desk article: "Holding Measurements when Probes are out of Range"
• Contact measureQuick support: support@measurequick.com