# Ref Tools vs Viessmann Access

The clearest difference is update cadence: Ref Tools at every 5 weeks against Viessmann Access's every 4 months. Viessmann Access's advantage is iOS requirement (12 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Ref Tools ships an update every 5 weeks, Viessmann Access every 4 months. The most recent releases landed on September 29, 2026 and August 12, 2026 respectively.

## The numbers

| Metric | Ref Tools | Viessmann Access |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.9 (52 ratings)](https://appshunter.io/ios/app/ref-tools/id472312541/reviews)** | — |
| Number of ratings | **52** | — |
| Positive reviews | 57.6% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 4 months |
| Monetization | Free | — |
| Size | 98 MB | 52 MB |
| Requires iOS | 15.0 | **12** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Danfoss A/S](https://appshunter.io/developer/423984644) | [Viessmann IT Service GmbH](https://appshunter.io/developer/1801739683) |

## What reviewers say

### Ref Tools

[App page](https://appshunter.io/ios/app/ref-tools/id472312541)

This app provides HVACR technicians with essential tools and information for field service. It includes refrigerant calculators, troubleshooting guides, product finders, and access to spare parts. Listen to educational podcasts to enhance your knowledge on the go.

**Highlights:** Refrigerant Slider for P/T calculations, Solenoid valve coil testing tool, Refrigeration system troubleshooting guide, Product data finder, Spare parts ordering, Low-GWP refrigerant comparison, TXV Superheat optimization, Educational podcasts

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 👍 Useful tool for HVAC/R techs
- 👍 Great idea for an app
- 👍 Best refrigeration and hvac app
- 👍 Useful App for HVACR
- 👍 Brilliant app

**What reviewers complain about**

- 🐛 Crashes instantly on launch
- 🐛 App won’t open on iPhone
- 🐛 Flashes up and disappears
- 🐛 Cannot open app
- 🐛 Immediately shuts off

**Reported bugs**

- CRASHED instantly on Mac Mini M4
- App won’t open on iPhone
- App flashes up and disappears
- Cannot open app
- Immediately shuts off since recent release

**Requested features**

- More residential AC information
- Troubleshooter for Residential & Commercial
- Add SP22 refrigerant
- Add R-11 refrigerant
- Add R-123 range down to 40 degrees


### Viessmann Access

[App page](https://appshunter.io/ios/app/viessmann-access/id1533222623)

**In-app purchases:** none


## Frequently asked questions

### Is Ref Tools free?

Ref Tools is free to download, with no in-app purchases.

### Is Viessmann Access free?

Viessmann Access is free to download, with no in-app purchases.

### Do Ref Tools or Viessmann Access have ads?

Neither Ref Tools nor Viessmann Access shows ads.

### Which is updated more often, Ref Tools or Viessmann Access?

Ref Tools ships an update every 5 weeks, and Viessmann Access every 4 months. Most recently, Ref Tools was updated on September 29, 2026 and Viessmann Access on August 12, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*