Comparison

Carrier® Service Technician vs Sizing US/CA

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Carrier® Service Technician

This app helps HVAC/R technicians quickly identify and locate necessary parts for repairs on any equipment, whether for warranty or non-warranty services. It offers advanced tools for troubleshooting, system calculations, and accessing technical documentation, all from the job site.

Highlights
  • AI Assistant for troubleshooting
  • System Capacity Calculator
  • Intelligent Equipment Search
  • Parts Identification & Cross-Reference
  • Warranty & Service History Lookup
  • Nearest Parts Center Locator
  • Technical Literature Access
Features
Read full description

Solving challenging HVAC/R problems is your job. Helping you get the right parts, supplies, and equipment—and manage sites in the field—is ours. The Carrier Service Technician app brings residential and commercial technician tools together in one Carrier experience. Whether you’re standing in front of a residential unit or covering commercial sites and equipment, the app is built for how technicians actually work on the job. Use the same Carrier sign-in you already have. Your role and permissions carry over, so you see the sites, equipment, and content you’re authorized to access—no new account, no new password. RESIDENTIAL TECHNICIAN EXPERIENCE Whether it’s warranty repairs for Carrier equipment or non-warranty repairs on any make or brand, the app helps you identify the right part at the job site. On-board GPS helps you find the closest location for parts when you need them. COMMERCIAL TECHNICIAN EXPERIENCE Field-ready tools for commercial sites and equipment—without opening a laptop. Get a quick read on the sites you cover, check equipment status on the spot, and dig into site and equipment details when you need specs and history. Work offline in basement mechanical rooms or on rooftops with no signal; your data caches and syncs when you’re back online. Meet Willis—ask about an alarm code for troubleshooting steps, or search official commercial OEM manuals and pull the section you need so you spend less time in PDFs and more time fixing the unit. KEY FEATURES Residential & field service • AI Assistant (Beta) — Ask technical questions, get support, and troubleshoot using model number inputs • View Customer System Online — Look up customer details with advanced search filters • System Capacity Calculator — Calculate airflow capacity based on job-site conditions and specs • Product Registration — Register equipment quickly from the field • Intelligent Equipment Search — Find equipment by scanning a serial barcode or entering a serial or model number • Parts Identification — Access accurate parts lists for selected equipment • Technical Literature Access — View technical documents with advanced filtering • Warranty & Service History Lookup — Retrieve warranty details and past service history by serial number • Nearest Parts Center Locator — Use GPS to find the closest Carrier Parts Sales Center and get directions • Totaline® Parts Cross-Reference — Find equivalent and compatible parts • Job Management — Create and manage job records and associate parts for future reference • Secure HVACPartners Access — Log in for restricted technical content and documents • Product Catalog — Browse and search the full Carrier product catalog • Technician Training Resources — Access online training modules • Tech Tips Video Library — Watch short, expert-led troubleshooting videos • Interactive Troubleshooting — Step-by-step guided diagnostics • Bluetooth Diagnostics & Firmware Updates — Pair with compatible systems for real-time fault data, performance metrics, and remote firmware updates • NFC Connectivity for Installer Tools — Configure installer settings, retrieve diagnostics, and support service board replacement on supported equipment Commercial field tools • Site View — Quick status across every site you cover • Device Manager — Equipment status when you’re on site • Site & Equipment Details — Specs and history in the field • Offline Mode — Keep working without signal; sync when you’re back online • Willis — Alarm troubleshooting and commercial OEM manual lookup • Faster Field Workflows — Quicker loads and fewer taps for common tasks One app. Same Carrier sign-in. Built for technicians in the field—residential and commercial.

About

Sizing US/CA

This utility app helps installers determine the correct size of flexible gas piping for their projects. It calculates the appropriate pipe size based on gas type, tubing length, supply pressure, and flow capacity. Users can also access installation guides and product information.

Highlights
  • Flexible gas pipe sizing
  • US and CA location selector
  • Automatic value adjustment
  • Certification card access
  • Installation guide viewer
  • Product search
  • Direct contact with developer
Features
Read full description

Size Gastite® and FlashShield™ flexible gas piping with this convenient and easy-to-use application for the iPhone. This app allows flexible gas pipe installers to determine the appropriate size Gastite pipe recommended for the installation at hand. Based on the project’s gas type, length of tubing run, supply pressure, pressure drop, and flow capacity – the app will calculate the appropriate size Gastite/FlashShield CSST for your application.
 
 Features
: Includes a location selector for US and CA 
 Scroll wheel automatically adjusts depending on values selected Find your certification card to link a digital version to your device
 FAQs View the latest Design and Installation Guide Search for Gastite and FlashShield products Contact Page submits questions and requests directly to Gastite 
The Gastite and FlashShield flexible gas piping systems are designed and warranted to provide sufficient gas volume and pressure for proper appliance performance using the appropriate sizing tables and methods detailed in the Design and Installation Guide and this Mobile Sizing App. 
Accordingly, the design pressure loss on the Gastite and FlashShield piping system under maximum probable flow conditions, from the point of delivery to the inlet connection of the equipment shall be such that the supply pressure at the equipment is greater than the minimum pressure required for proper equipment operation. Minimum Requirements - iOS version 8

Screenshots

Carrier® Service Technician4 screens
Sizing US/CA4 screens

Verdict

The call

The clearest difference is rating: Carrier® Service Technician at 4.1 against Sizing US/CA's 3.2. Carrier® Service Technician also leads on ads (none vs shown) and review sentiment (32% vs 11%). Sizing US/CA's advantage is iOS requirement (10.0 vs 15.1). On price, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Carrier® Service Technician holds the better App Store score, 4.1 against 3.2. That said, the two scores are not equally well evidenced: Carrier® Service Technician has 108 ratings behind it against 13, so its average is the more settled of the two. Written reviews point the same way: 32% of Carrier® Service Technician's written reviews are positive against 11% of Sizing US/CA's.

UpkeepUpdate frequency

Carrier® Service Technician ships an update fortnightly, Sizing US/CA every 6 weeks. The most recent releases landed on September 21, 2026 and June 3, 2026 respectively.

Scorecard7 real differences · 3 level
Carrier® Service Technician versus Sizing US/CA: the parameters behind the verdict, then further details
ParameterCarrier® Service TechnicianSizing US/CA
PriceFreeFree
Rating4.1 (108 ratings) — better3.2 (13 ratings)
Positive reviews32.4% of reviews — better11.1% of reviews
Number of ratings108 — better13
Update frequencyFortnightly — betterEvery 6 weeks
AdsNo — betterYes
In-app purchasesNoNo
MonetizationFree — betterAd-supported
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.110.0 — better
Further details — not scored
Size174 MB27 MB
Age rating4+17+
DeveloperCarrier CorporationGastite Products LLC

Customer experience

Carrier® Service Technician

All ratings108 ratings
Positive81.5%
Neutral0.0%
Negative18.5%
Written reviews34 reviews
Positive32.4%
Neutral0.0%
Negative67.6%

Sizing US/CA

All ratings13 ratings
Positive46.2%
Neutral15.4%
Negative38.5%
Written reviews9 reviews
Positive11.1%
Neutral11.1%
Negative77.8%

In-app purchases

None

Carrier® Service Technician

No in-app purchases

None

Sizing US/CA

No in-app purchases

Questions

Is Carrier® Service Technician free?
Carrier® Service Technician is free to download, with no in-app purchases.
Is Sizing US/CA free?
Sizing US/CA is free to download, with no in-app purchases.
Which has better reviews, Carrier® Service Technician or Sizing US/CA?
Carrier® Service Technician is rated higher. Carrier® Service Technician averages 4.1 out of 5 from 108 ratings, while Sizing US/CA averages 3.2 from 13 ratings.
Do Carrier® Service Technician or Sizing US/CA have ads?
Sizing US/CA shows ads; Carrier® Service Technician does not.
Which is updated more often, Carrier® Service Technician or Sizing US/CA?
Carrier® Service Technician ships an update fortnightly, and Sizing US/CA every 6 weeks. Most recently, Carrier® Service Technician was updated on September 21, 2026 and Sizing US/CA on June 3, 2026.

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