✓ 100% Offline v6.42 · 1,500+ Solutions ⚡ Bluetooth Instruments ⚡ A2L Ready · R-454B · R-32

Every tool a tech needs.
One app. Zero signal required.

Guided diagnostics, AI nameplate scanner, live Bluetooth instruments, weather-adjusted charge targets, voice co-pilot, and customer-ready reports. Built by techs, for techs.

1,500+
Field Solutions
18
Diag Categories
12
Brand Decoders
8
Calculators
FIELDMODE™
BT Live
Scanned Equipment
Carrier 24ACC636A003
3 Ton · 16 SEER · 2016 · R-410A
!
Known Issue: Spine Fin Coil Corrosion
2010–2018 models · High severity
165.8
Suction PSIG
●BT
Live Probe
12.4°F
Superheat ✓
9.2°F
Subcooling ✓
Home
📷
Scan
Diag
🤖
AI
Tools
Weather SH Target
12–16°F ✓
Bluetooth Signal
Fieldpiece JL3 ●
Life Status
62% — Aging Unit
🔥 Gas Furnace 57❄️ Cooling 92🌬️ Mini-Split 86⚡ Electrical 63💧 Water Heaters 61♻️ Heat Pump 59🧊 Refrigerant 55🏭 Commercial RTU 53🔊 Noise 47🌡️ Thermostat 46💨 Airflow 43⚙️ Compressor 41🏛️ Controls 40Ductwork 39🌿 IAQ 36🔥 Boiler / Steam 35💧 Water Leaks 32Odors 30 🔥 Gas Furnace 57❄️ Cooling 92🌬️ Mini-Split 86⚡ Electrical 63💧 Water Heaters 61♻️ Heat Pump 59🧊 Refrigerant 55🏭 Commercial RTU 53🔊 Noise 47🌡️ Thermostat 46💨 Airflow 43⚙️ Compressor 41🏛️ Controls 40Ductwork 39🌿 IAQ 36🔥 Boiler / Steam 35💧 Water Leaks 32Odors 30
See It in Action

Three scenarios. Zero Googling.

Watch how Fieldmode guides a tech from symptom to solution in minutes.

Heating
No Heat Call → Root Cause
🏠Home
🔍Diag
📋Equip
🧮Calc
FIELDMODEv6.42
What's the call today?
🔥
Heating
250+ solutions
❄️
Cooling
100+ solutions
🌬️
Mini-Split
90+ solutions
💧
Water Htrs
70+ solutions
⚠ 28°F tonight — check frozen condensate drain lines
← HeatingHEATING
What type of heating system?
Gas furnace
Oil burner
Boiler / Hydronic
Steam heat
Heat pump
← Gas FurnaceHEATING
What's happening?
No ignition / burner won't light
Ignites but shuts off / short-cycles
Weak heat / not reaching setpoint
Blower runs, no heat
Error code / flashing LED
← Short CyclingHEATING
ModerateGas Furnace
90%+ Furnace — Pressure Switch Fault
1. Check inducer motor — listen for full-speed spin before ignition.
2. Inspect flue/intake pipes for ice or blockage at termination.
3. Test pressure switch — typical −0.50" to −1.0" WC set point.
4. Check condensate drain — blockage opens secondary pressure switch.
WEATHER NOTE
28°F outdoor — check condensate for freezing. Blocked drain = identical short-cycle symptoms.
Equipment-first navigation surfaces the right path instantly — no digging through manuals.
AI Scanner
Scan Nameplate → Full Profile
🏠Home
📷Scan
📋Equip
🤖AI
FIELDMODESCAN
📷
Point at any nameplate
Dirty · Corroded · Faded — OK
AI reads manufacturer, model,
serial, refrigerant, tonnage & age
Reading...AI
Decoding nameplate...
✓ Manufacturer: Trane
✓ Model decoded: 3 ton · 16 SEER
⟳ Serial → install year...
⟳ Known issues check...
✓ Profile LoadedSCAN
Trane 4TTR6036J1000AA
3.0
Tons
16
SEER
2018
Install yr
R-410A
Refrigerant
⚠ Known Issue Flagged
Climatuff compressor bearing wear · 2016–2020 · Moderate
Auto Parts List
35/5 µF cap · Contactor 2P 40A · TXV 3T R-410A
FIELDMODEAI
AI loaded with full unit context
I see you're on a Trane 4TTR6036 — 3-ton, 2018. ⚠ Climatuff bearing wear is flagged on this range. What are you seeing on the call?
Scan → known issues → AI context-loaded in seconds. 12 brand decoders, 42 tracked issues.
AI Co-Pilot
Equipment-Aware Diagnosis
🏠Home
🔍Diag
📋Equip
🤖AI
FIELDMODEAI PRO
AI Tech Mentor · Equipment-Aware
👋 I see you're on a Carrier 24ACC636A003 — 3-ton, 2016, Spine Fin issue flagged. What are you seeing?
FIELDMODEAI PRO
👋 I see you're on a Carrier 24ACC636A003. What are you seeing?
Suction is 30°F and head pressure is high. Outdoor ambient 95°F.
FIELDMODEAI PRO
👋 I see you're on a Carrier 24ACC636A003. What are you seeing?
Suction is 30°F, head pressure high. Outdoor 95°F.
FIELDMODEAI PRO
Suction 30°F, high head. Outdoor 95°F.
Classic restricted metering at 95°F. On this unit:

1. TXV — confirm full hunt/stroke. 30°F suction = restriction or overcharge.
2. Airflow — target 1,200 CFM (400/ton). High head at 95°F is a red flag.
3. Spine Fin coil flag on this unit — corroded coil shows exactly this pattern.

Weather-adj. SC target: 12–15°F at 95°F ambient.
The AI reads your scanned equipment and gives unit-specific answers — not generic HVAC advice.
Full Capabilities

Every tool. One app.
Zero context-switching.

Everything a service tech reaches for — unified into an offline-ready workflow where each tool feeds intelligence to the next.

🔍

Guided Diagnostic Trees

1,500+ field-tested solutions across 18 categories, up to 6 levels deep. Equipment-first branching covers gas furnace, oil burner, heat pump, mini-split, boiler, steam, commercial RTU, water heater, compressor, controls, IAQ, ductwork, electrical, refrigerant, noise, odor, and water leaks. Severity ratings and safety flags on every solution. Real-time weather notes injected per category.

1,500+ solutions18 categoriesup to 6 levels deep
📷

AI Nameplate Scanner

Point at any nameplate — dirty, corroded, or faded. AI extracts manufacturer, model, serial, refrigerant type, tonnage, BTU, voltage, SEER, and age instantly. Model number decoders for 12 brands decode series, specs, and install year from the serial format. Result loads the equipment profile, known issues database, and AI context in one step.

Carrier · Trane · GoodmanRheem · Lennox · York · +6 more
🌡️

Weather-Adjusted Charge Targets

Live GPS + NWS API auto-calculates superheat and subcooling targets for both TXV and fixed-orifice systems based on real outdoor conditions — no manual lookup ever. Seasonal alerts for frozen condensate, spring startup, and peak load events. Targets flow into every diagnostic, calculator, and report automatically.

Live GPS weatherAuto SH/SC targets
⚠️

Equipment Intelligence — Known Issues Database

After scanning a nameplate, Fieldmode cross-references your unit against a curated database of manufacturer-specific problems flagged by model range and year. Known issues surface immediately — before you open a panel. Life status bar shows Young / Mid-life / Aging / End-of-life with percentage. Auto-generates a common parts list based on equipment type, tonnage, and series. Includes manufacturer service portal links and support phone numbers for 19 brands.

10 brands tracked42 known issues19 mfr service portalsAuto parts list by tonnage
📋

Job Log & Session History

Log customer name, equipment details, serial number, tech name, company, and timestamped notes per job. Full history with recall. Session data flows into both report types automatically — no re-entry required. Tech and company name persist across all jobs.

💰

Repair vs. Replace Advisor

5-year total cost of ownership comparison using unit age, repair cost, replacement cost, refrigerant type, and utility rate. IRA tax credit calculator for qualifying R-454B and heat pump replacements ($2,000). Monthly financing estimates with adjustable rate. Generates a customer-ready slide to close the sale on-site.

IRA $2,000 credit calcMonthly financing est.
📊

P-T Chart — 7 Refrigerants

Full pressure-temperature chart with industry-standard PSIG values for R-410A, R-22, R-134a, R-32, R-404A, R-407C, and R-454B. Multi-refrigerant overlay view. Color-coded curves. Smooth interpolation for any pressure input. Fully offline — no connection needed ever.

R-410A · R-22 · R-134aR-32 · R-404A · R-407C · R-454B

A2L Refrigerant Guide

35-node interactive guide covering every A2L refrigerant now going into new equipment. Flammability facts in plain language, tool compatibility by brand, handling rules by job type (attic, closet, commercial rooftop, mini-split), retrofit guidance, EPA 608 and ASHRAE 15 reference, and a customer explainer mode for homeowners who ask about the new refrigerants.

R-454B · R-32 · R-452B · R-466AFlammability · Tools · Handling · CodeUpdated 2025
🔧

Parts Cross-Reference

Search replacement parts across Titan, Mars, Packard, and other aftermarket suppliers. Auto-populated from the scanned unit. Vision-identified parts added to the active session. Tap to copy part numbers for ordering. Includes capacitors, contactors, motors, and thermostats with OEM cross-refs.

📡

Bluetooth Live Instruments

Pair real gauges via Web Bluetooth and watch readings stream in real time. Suction, discharge, liquid line, ambient — SH, SC, and temp split auto-calculate as you watch. Real-time alerts for floodback, overcharge, and undercharge. Live values auto-populate calculator fields. No manual entry.

Chrome / AndroidFieldpiece · Testo · YJACKMulti-probe slots
📡

Offline-First PWA

Full service worker with intelligent caching. Every feature — diagnostics, calculators, PT chart, parts lookup, job log — works without cell signal. Installs as a PWA directly from the browser on iOS and Android. No app store required. Launches from the home screen like a native app.

100% offline capableHome screen install
AI Suite

Four AI modes. One brain
behind every call.

Scan a unit once. Every AI mode — chat, voice, and vision — shares that context automatically.

🤖
AI Co-Pilot — Senior Tech Mentor
Powered by Claude Sonnet · Equipment context loaded automatically on scan

When you scan a nameplate, the AI receives the full equipment profile — decoded specs, known issues, refrigerant type, age, and live outdoor weather. It proactively flags concerns before you ask. Answers are unit-specific, not generic HVAC advice.

Example: "I see you're on a Carrier 24ACC636A003 — 3-ton, 2016. Spine Fin coil corrosion is flagged on this range. High head + low suction often points to a restricted TXV or the corroded coil itself. What are your pressures?"
🎙️
Voice Co-Pilot
Hands-free · Web Speech API · TTS responses

Activate hands-free mode and ask questions verbally while working inside the unit. Answers are spoken back via text-to-speech. Same full equipment context as the chat — just no hands required. Perfect for attic installs, crawlspaces, and rooftop units in summer heat.

Note: Voice mode requires Chrome or Android. Web Speech API is not available on Safari/iOS — native app will unlock this.
👁️
AI Vision — 3 Photo Modes
Diagnose · Parts ID · Before/After documentation

Take a photo and let AI do the work. Diagnose: photo → fault identification + severity rating. Parts ID: photo → component specs + replacement options. Before/After: document repair quality for customer records and liability. All findings stored in the job session and flow into reports automatically.

Field Calculators

Eight calculators. All offline.

Weather-aware where applicable. Bluetooth readings auto-populate fields. Every answer in seconds with no cell signal.

🌡️
Superheat
TXV and fixed-orifice modes. Weather-adjusted targets from live outdoor conditions. Accepts Bluetooth probe readings.
❄️
Subcooling
Weather-adjusted targets. Auto-computes from Bluetooth live readings. Flags overcharge and undercharge in real time.
🏠
BTU / Heat Load
Manual J-style load estimate from square footage, climate zone, insulation class, and window area.
💨
CFM / Airflow
Required airflow from tonnage and system type. Temperature rise and split verification for supply and return.
Ohm's Law
Solve for voltage, current, resistance, or power. Component testing, motor circuits, transformer outputs.
🔋
Capacitor µF
Calculate actual microfarad from run test. Flag as good, marginal, or replace based on ±6% tolerance.
🌡️
Temperature
°F ↔ °C conversion with common HVAC reference points and Kelvin. Instant, offline.
🧊
Refrigerant Charge
Calculate oz. to add based on lineset length, tonnage, and factory charge. Accounts for diameter and vertical rise.
Report Generation

Two reports. One tap each.

Both reports pull from your entire job session — scanned equipment, weather, diagnostic path, Bluetooth readings, AI vision findings, and parts list. No copy-paste, no re-entry.

📋 Tech Service Report
Branded PDF for your records or company management. Auto-numbered steps, measurements, and parts required.
  • Equipment profile — nameplate data + decoded specs
  • Full diagnostic path with each question and answer
  • Fix steps with numbered sequence
  • Tools and parts required for the repair
  • Safety flags and severity rating
  • Live Bluetooth readings embedded
  • Weather data at time of service
  • AI vision findings (if photo taken)
  • Tech name, company, date and time
👤 Customer-Facing Report
AI-written plain-English narrative for the homeowner. No jargon. Generated and personalized by customer name.
  • "What We Found" — plain-English diagnosis summary
  • "What We Did" — actions taken in plain language
  • "Recommendations" — proactive advice and next steps
  • Repair vs. Replace analysis with IRA tax credits
  • Equipment life status with percentage bar
  • Known issues callout (if applicable)
  • Annual savings and payback period (if replacing)
  • Personalized by customer name throughout
Workflow

From truck to diagnosis in minutes.

Four steps that replace three apps, a binder, and a call back to the office.

1
📷

Scan the Nameplate

Point at any nameplate — dirty or corroded. AI reads manufacturer, model, serial, refrigerant, tonnage, SEER, and age instantly.

~5 seconds
2
⚠️

Get the Full Picture

Fieldmode decodes the model, calculates unit age, surfaces known issues by severity, shows specs, and loads the AI with full context.

Instant
3

Diagnose + Measure

Walk guided decision trees, pair Bluetooth probes for live readings, or ask the AI co-pilot with hands-free voice mode.

30–90 sec
4
📋

Generate the Report

One tap creates a tech service report or AI-written customer-facing report with repair vs. replace and IRA credit calculations.

1 tap
Comparison

How Fieldmode stacks up.

Built from scratch for field technicians — not adapted from a general-purpose app.

FeatureFIELDMODE™BluonMeasureQuickHVAC BuddyRef Tools
Guided diagnostic trees 1,500+ solutions
AI nameplate scanner Any nameplate
Known issues database 42 issues / 10 brands 500k+ units
Weather-adjusted SH/SC targets Live GPS + NWS~ Manual entry~ Manual entry
Bluetooth instrument integration Chrome/Android Native iOS+Android
AI conversational assistant Voice + text
AI photo diagnosis + parts ID 3 vision modes
AI-written customer report Plain-English PDF
Tech service report PDF Auto-generated Measurement report
Repair vs. Replace + IRA credits Full calculator
PT chart refrigerant coverage 7 refrigerants Extensive Extensive Extensive 80+ refrigerants
Works fully offline Full PWA
Free tier available All diagnostics free~ Limited~ Limited
From the Field

What techs are saying.

Scanned a 2015 Trane and it immediately flagged Spine Fin coil corrosion as a known issue. Opened the unit — sure enough, coil was eaten up. Would've taken me 20 minutes to figure that out on my own.

🔧
Beta Tester
Residential Service Tech · 8 yrs

The weather-adjusted superheat targets alone are worth it. I used to pull up three different apps to check conditions, look up the chart, and do the math. Now it's just there when I need it.

❄️
Beta Tester
Commercial HVAC Tech · 12 yrs

My new guy used the diagnostic trees on his second week and caught a cracked heat exchanger I probably would've sent him back for. The guided questions don't let you skip the important checks.

🏢
Beta Tester
Service Manager · 15-tech shop

Real feedback from field testing. Named testimonials coming at public launch.

Pricing

Less than a filter.
More than a textbook.

One prevented callback pays for a full year of Pro.

Apprentice
Free
 
Get started at no cost. No credit card. No expiration.
Start Free →
  • All 1,500+ diagnostic solutions
  • 18 guided diagnostic categories
  • P-T chart — 7 refrigerants
  • 8 field calculators (offline)
  • Error code lookup (15+ manufacturers)
  • Parts cross-reference database
  • Full offline PWA
  • Repair vs. Replace calculator
Pro
$14.99/mo
or $119/year — save 34%
Everything you need on every call. All AI tools included.
Start Pro →
  • Everything in Apprentice
  • AI Chat — Senior Tech Mentor
  • Voice Co-Pilot (hands-free mode)
  • AI Nameplate Scanner + Vision
  • AI Vision — Diagnose / Parts ID / Before-After
  • Bluetooth live instrument integration
  • Weather-adjusted SH/SC targets
  • Tech service report generation
  • AI-written customer-facing report
  • IRA tax credit calculator
  • 12-brand model number decoders
  • 42 known issue alerts
  • Job log + history
Team
$9.99/tech/mo
minimum 5 technicians
Equip your whole crew. 33% off Pro pricing at volume.
Contact Sales →
  • Everything in Pro
  • Volume discount (33% off per tech)
  • Team management dashboard
  • Shared job logs across techs
  • Fleet diagnostic analytics
  • Priority support
  • Onboarding session included
Free to Start · No Signup Required

Stop Googling on the job.

1,500+ field-tested solutions. Bluetooth instruments. AI scanner. Voice co-pilot. Customer reports. Works offline. No signup to start.

A2L Refrigerant
A2L Field Reference Guides
Everything you need to know about the refrigerants replacing R-410A — flammability, tools, handling, and code compliance.
All A2L Guides →
Overview
What Is A2L Refrigerant?
Classification, flammability facts, tool requirements, and handling rules — complete field reference.
Coming Soon
R-454B vs R-410A: What Changes
Pressures, oil, leak detection, charging procedure, and tools — side-by-side.
Coming Soon
Is R-454B Flammable?
The real answer — the 3 conditions required, risk by scenario, and a customer explainer.
View All 7 A2L Guides →
Field Articles
HVAC Diagnostic Articles
Deep diagnostic guides written by technicians for technicians. New articles dropping weekly.
All Articles →
Heating
Gas Furnace Pressure Switch Faults
Every cause, every fix — from condensate blockage to inducer failure. Read now →
Heat Pumps — Coming Soon
Heat Pump Not Heating in Cold Weather
Reversing valve, defrost faults, low charge in heating mode, and aux heat sequencing.
Mini-Splits — Coming Soon
Mini-Split Error Codes Guide
Mitsubishi, Daikin, Gree, LG, Pioneer — every brand's code system explained.