# Rinnai Central vs Flag Protocol

The clearest difference is rating: Flag Protocol at 2.6 against Rinnai Central's 1.6. Rinnai Central's advantage is ratings volume (341 vs 5) and update cadence (monthly vs every 2 months). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Flag Protocol holds the better App Store score, 2.6 against 1.6. That said, the two scores are not equally well evidenced: Rinnai Central has 341 ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 9% of Rinnai Central's written reviews are positive against 0% of Flag Protocol's, so the app with the better star average is not the one people write more warmly about.

Rinnai Central ships an update monthly, Flag Protocol every 2 months. The most recent releases landed on October 21, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Rinnai Central | Flag Protocol |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.6 (341 ratings)](https://appshunter.io/ios/app/rinnai-central/id6444321202/reviews) | **[2.6 (5 ratings)](https://appshunter.io/ios/app/flag-protocol/id6752128454/reviews)** |
| Number of ratings | **341** | 5 |
| Positive reviews | **9.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Monthly** | Every 2 months |
| Monetization | Free | Free |
| Size | 79 MB | 14 MB |
| Requires iOS | **15.4.1** | 18.2 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Rinnai America Corp](https://appshunter.io/developer/1045235922) | [Curayt, LLC](https://appshunter.io/developer/1012363586) |

## What reviewers say

### Rinnai Central

[App page](https://appshunter.io/ios/app/rinnai-central/id6444321202)

This app connects Rinnai tankless water heater owners to their devices for temperature control and scheduling. Professional installers can use it to register appliances, perform service, access documentation, and order parts.

**Highlights:** Adjust water temperature, Schedule hot water, Activate recirculation, Register appliances, Perform remote service, Access documentation, Order replacement parts

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Works great
- 🚀 Much improved
- 🚀 Fantastic
- 🚀 Working perfectly now

**What reviewers complain about**

- 🐛 Doesn't work at all
- 🐛 Bug in 4.3.0
- 🐛 Awful. Just terrible
- 🐛 Lousy App
- 🐛 Rinnai does not care

**Reported bugs**

- Control failed is still happening in latest version
- Login screen freezes
- Incompatible with older devices

**Requested features**

- Add device through Bluetooth missing
- Dark mode option
- Advanced analytics dashboard


### Flag Protocol

[App page](https://appshunter.io/ios/app/flag-protocol/id6752128454)

This app provides up-to-date information on when to fly the US flag at full staff versus half staff. It's designed to be free and easy to use, ensuring you always display your flag correctly.

**Highlights:** Full staff vs. half staff guidance, Up-to-date flag display information, Easy setup, Free to use

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

**In-app purchases:** none


## Frequently asked questions

### Is Rinnai Central free?

Rinnai Central is free to download, with no in-app purchases.

### Is Flag Protocol free?

Flag Protocol is free to download, with no in-app purchases.

### Which has better reviews, Rinnai Central or Flag Protocol?

Flag Protocol is rated higher. Rinnai Central averages 1.6 out of 5 from 341 ratings, while Flag Protocol averages 2.6 from 5 ratings.

### Do Rinnai Central or Flag Protocol have ads?

Neither Rinnai Central nor Flag Protocol shows ads.

### Which is updated more often, Rinnai Central or Flag Protocol?

Rinnai Central ships an update monthly, and Flag Protocol every 2 months. Most recently, Rinnai Central was updated on October 21, 2026 and Flag Protocol on October 11, 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.*