firestar-alert

A lightweight Raspberry Pi monitor for the Central Boiler Firestar XP wood-fired outdoor boiler.

Note: This project is not affiliated with, endorsed by, or in any way connected to Central Boiler. It reads data from the local HTTP status page the Firestar XP controller already exposes on your home network — the same page viewable in any browser. No proprietary protocols are reversed, no cloud services are accessed, and no Central Boiler systems are modified.

Background

Central Boiler offers a paid cloud subscription service that provides remote monitoring, advanced alerts, and historical data for the Firestar XP. If you just want to know whether your fire has gone out or the boiler has shut off unexpectedly — and you'd rather not pay a monthly fee — this project does exactly that using the local web interface the boiler already exposes on your network.

The Firestar XP controller hosts a small status page at a static IP on your home network. This project runs a Python script on a Raspberry Pi that polls that page every minute, parses the Furnace Status, Water Temp, and Fire Temp values, and sends a push notification to your phone if anything falls outside acceptable limits.

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How It Works

The Firestar XP serves a plain HTML/JavaScript status page on your local network. The page embeds the furnace state as an integer in inline JavaScript, renders Water Temp and Fire Temp as plain text in an HTML table, and populates two alarm fields via JavaScript string literals. This script fetches that page, extracts all of those values with a regex and BeautifulSoup, compares them against configurable thresholds, and fires a push notification via ntfy.sh when a threshold is violated.

The alarm fields carry firmware fault codes (e.g. DOOR, T.C., BYPASS) which are mapped to human-readable labels using the same lookup table the Firestar XP's own web UI uses.

No login, no cloud API, no proprietary protocol — just a local HTTP GET.

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Features

• Polls http://192.168.1.113 every 5 minutes under normal conditions

• Sends push notifications via ntfy.sh (free, no account needed)

• Detects and alerts on:

  • Furnace Status ≠ ON (fire out, fault condition, etc.)
  • Water Temp < 165 °F
  • Fire Temp < 200 °F
  • Any non-empty alarm field reported by the firmware (Door Open, Failed Thermocouple, Gas Fail, Bypass Handle Up, etc.)

• Alarm codes are resolved to human-readable labels using the same lookup table as the Firestar XP web UI; unknown codes fall back to their raw value

• Retries up to 3 times before alerting if temp values are unreadable

• Smart alert backoff — avoids spamming you if the problem persists:

  Alerts sent	Poll interval
  0 (normal)	5 minutes
  1st alert sent	10 minutes
  2nd alert sent	30 minutes
  3rd+ alert sent	60 minutes
  6 hours in error	Stop alerting; check hourly for recovery

• Sends a recovery notification when the boiler returns to normal

• Sends a startup notification with current temps and active config on every service start

• Restarting the service resets all alert backoff state

• Runs as a systemd service — starts automatically at boot, restarts on crash

• All thresholds and intervals are configurable via config.ini without editing code

• Logs to the systemd journal and a local monitor.log file with automatic rotation (1 MB cap, 3 backups kept)

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Future Ideas

Temperature History

The boiler page doesn't expose a history API, but since this script already polls every minute, it's straightforward to extend it to log readings to a local database or CSV file. That data could then be visualized with tools like:

• Grafana + InfluxDB — the standard self-hosted time-series dashboard stack. Runs well on a Pi.
• Home Assistant — if you already use it, the monitor could push readings as sensors.
• A simple CSV log + Python/spreadsheet for a lightweight option.

If you'd like temperature history tracking added to this project, open an issue or submit a PR.

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Requirements

• Raspberry Pi (any model with a network connection)
• Python 3.9+
• Your Firestar XP controller assigned a static IP on your local network (default used here: 192.168.1.113)
• The ntfy app installed on your phone (iOS or Android)

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Project Structure

firestar-alert/
├── monitor.py               # Main polling and alerting script
├── config.ini               # Configuration — edit this before deploying
├── requirements.txt         # Python dependencies
├── firestar-alert.service   # systemd unit file
├── install.sh               # Installer script for the Raspberry Pi
├── monitor.log              # Created at runtime — rotates at 1 MB, keeps monitor.log.1-.3
└── state.json               # Created at runtime — cleared on every service restart

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Installation

1. Copy the project to your Raspberry Pi

scp -r firestar-alert <user>@<pi-ip-address>:~/firestar-alert

Or clone directly on the Pi:

git clone https://github.com/csphu/firestar-alert.git
cd firestar-alert

2. Edit the configuration

SSH into the Pi, then:

cd ~/firestar-alert
nano config.ini

Fill in the following values (see Configuration Reference below):

• [boiler] → url — the local IP of your Firestar XP (e.g. http://192.168.1.113)
• [ntfy] → topic — the topic name you subscribed to in the ntfy app

3. Run the installer

chmod +x install.sh
./install.sh

The installer will:

1. Create a Python virtual environment at ~/firestar-alert/venv
2. Install requests and beautifulsoup4
3. Register and enable the systemd service

Note: If you run install.sh from within the project directory (the normal case after scp), it will detect that and skip the file copy step automatically.

4. Start the service

sudo systemctl start firestar-alert

5. Verify it's running

sudo systemctl status firestar-alert

6. Watch live logs

journalctl -u firestar-alert -f

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Configuration Reference

All settings live in config.ini.

[boiler]

Key	Default	Description
url	http://192.168.1.113	URL of the Firestar XP status page
water_temp_min	165	Alert threshold for Water Temp (°F)
fire_temp_min	200	Alert threshold for Fire Temp (°F)

[ntfy]

Key	Default	Description
topic	your-unique-topic-name	Your ntfy topic name — must match what you subscribed to in the app. Make it unique.
server	https://ntfy.sh	ntfy server URL. Change only if self-hosting.

[alerts]

Key	Default	Description
normal_interval	5	Polling interval when everything is OK (minutes)
interval_after_first_alert	10	Polling interval after 1st alert (minutes)
interval_after_second_alert	30	Polling interval after 2nd alert (minutes)
interval_after_third_alert	60	Polling interval after 3rd+ alert (minutes)
max_error_hours	6	Hours before alerts stop (checks hourly for recovery)

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ntfy.sh Setup

ntfy is a free, open-source push notification service. No account is needed.

1. Install the ntfy app on your phone (iOS / Android)
2. Tap + and subscribe to a topic name you make up (e.g. my-boiler-alerts)
3. Test it from any terminal: curl -d "test" ntfy.sh/my-boiler-alerts
4. Set that topic name in config.ini under [ntfy]

Security tip: Make your topic name long and hard to guess — anyone who knows it can subscribe and receive your notifications.

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Service Management

# Start / stop / restart
sudo systemctl start firestar-alert
sudo systemctl stop firestar-alert
sudo systemctl restart firestar-alert

# Enable / disable autostart at boot
sudo systemctl enable firestar-alert
sudo systemctl disable firestar-alert

# View status
sudo systemctl status firestar-alert

# Follow live logs
journalctl -u firestar-alert -f

# View all logs
journalctl -u firestar-alert --no-pager

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Alert Examples

Alerts appear as push notifications in the ntfy app with a 🔔 tag on startup, 🔥 for problems, and ✅ for recovery.

Startup notification (ntfy title): MONITOR STARTED

Time: 2026-03-03 11:49
Furnace: ON
Water:   186.4°F
Fire:    197°F
────────────────────
Water min: 165°F
Fire min:  200°F
Interval:  5m

Startup notification with active alarm (ntfy title): MONITOR STARTED

Time: 2026-03-04 08:12
Furnace: ON
Water:   191.6°F
Fire:    233°F
Alarm 2: BYPASS
────────────────────
Water min: 165°F
Fire min:  200°F
Interval:  5m

Problem alert (ntfy title): BOILER ALERT

Firestar XP Alert
Time: 2026-03-03 02:14
────────────────────
  • Furnace Status: OFF (expected ON)
  • Fire Temp: 143.0°F (min 200°F)
────────────────────
Furnace: OFF
Water:   158.2°F
Fire:    143.0°F

Alarm alert (ntfy title): BOILER ALERT

Firestar XP Alert
Time: 2026-03-04 09:47
────────────────────
  • Alarm 2: Door Open
────────────────────
Furnace: ON
Water:   190.5°F
Fire:    256°F
Alarm 2: Door Open

Recovery notification (ntfy title): BOILER RECOVERED

Firestar XP recovered.
Time: 2026-03-03 03:45
Furnace: ON
Water:   187.5°F
Fire:    312.0°F

Alarm Code Reference

Firmware code	Displayed as
GAS	Auto Relight
GAS2	Wood Ignition
HIGH	High Water
HIGH2	High Water Snapdisk
LOW	Low Water
DIAG	Diagnostics
DOOR	Door Open
E.F.	EEPROM Failure
T.C.	Failed Thermocouple
G.F.	Gas Fail
A-2	Auto Relight Failure
WEB	Web Connection Lost
(unknown)	Raw code as-is (e.g. BYPASS)

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Disclaimer

This project is not affiliated with or endorsed by Central Boiler Inc. "Firestar XP" is a product of Central Boiler. This software reads data from the local HTTP interface the device exposes on your own home network and does not interact with any Central Boiler cloud service, API, or server. Use at your own risk.

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Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

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License

MIT — see LICENSE.