Modular frost protection heating system for valves and pipes on boats
"Click, click, frost-free – modular heating rings, infinitely expandable."
Snap-in heating rings with click mounting, centrally controlled via BoatOpenIO extension board with MQTT and BoatOS integration. Install once, stays permanently in the boat. Combine as many rings as you want, each controllable independently.
Part of the Logbook Without Posing series – Volume 6.
This project is 100% open source and free. The complete story – every idea, mistake, detour and solution – is documented in the book series "Logbook Without Posing".
If you find this project useful and want to support active further development: buying the book series directly helps ensure that such projects can continue to evolve – so that everyone can use it out-of-the-box without needing special knowledge.
👉 Logbook Without Posing on Amazon
Already published:
- Volume 1: The Engine Runs
- Volume 2: Power Is Never Simple
- Volume 3: Sensors & Monitoring
- Volume 4: BoatOS – The Foundation
- Volume 5: BoatOS – The System
- Volume 6: The Valve Heater ← this project
All volumes available in German and English.
Classic cable heaters for valves and pipes:
- Dismantle and reinstall every year
- Wrapping cables in freezing temperatures with numb fingers
- Cable chaos in the engine room
- No monitoring, no alarm, no remote control
- Never the right length, never the right shape
Modular heating rings with snap-in mounting:
- Click mounting (simply snap onto the pipe) – 2 seconds per ring
- Heating foil 12V / 14W – even heat distribution
- 5/8 shell in ASA – robust, UV-resistant, positionable anywhere
- Freely combinable – 1 ring before valve, 1 behind valve, or along the entire pipe
- Centrally controlled – BoatOpenIO + BoatOS Dashboard with MQTT
- Independent channels – up to 8 rings per extension board
- Install once – stays permanently in the boat
| Parameter | Value |
|---|---|
| Voltage | 12V DC |
| Power | 14W per ring |
| Heating element | Self-adhesive heating foil 50x100mm |
| Sizes | 1" pipe, 2" pipe (more on request) |
| Material | ASA (UV-resistant, weatherproof) |
| Mounting | Snap-in (simply snap onto the pipe) |
| Width | 55mm |
| Opening | ~130° (for click mounting) |
| Component | Description |
|---|---|
| BoatOpenIO board | Extend existing BoatOS system |
| Shift register 74HC595 | 8-channel output control (I/O expansion) |
| Relays (8x) | Switch 12V for heating rings |
| DS18B20 | Temperature sensor (OneWire) optional |
| Bus bar | 12V power distribution for all rings |
- Snap-in mounting – 2 seconds per ring, no tools required
- Modular system – combine as many rings as needed (valves, pipes, T-pieces, etc.)
- 8 independent channels – each ring individually controllable
- Automatic control – rings switch at configurable outside temperature
- MQTT integration – full integration into the BoatOS network
- BoatOS Dashboard – monitoring, alarms, remote control
- JSON configuration – no firmware changes needed
- Shift register architecture – scalable, compact, reliable
- Stick heating foil onto the inner ASA shell (self-adhesive)
- Snap ring onto pipe/valve (1 second)
- Optional: zip ties through eyelets for additional security
- Apply Armaflex insulation on the outside
- Route cable to bus bar
Time per ring: approx. 2 minutes (including insulation)
- Solder shift register + relays on the extension board
- Integrate board into BoatOS system
- Supply bus bar with 12V and GND
- Connect heating ring cables to relays
- Configure MQTT (automatic detection by BoatOS)
- Create dashboard widget
- Set thresholds for automatic control
BoatOS automatically detects the MQTT topics. Create a dashboard widget, configure alarms, done.
boat/heating/temperature/outside → current outside temperature
boat/heating/status/ring1-8 → 0/1 (off/on) for each ring
boat/heating/mode → auto/manual/off
boat/heating/cmd/ring1-8 → on/off/auto for each ring
boat/heating/cmd/threshold → set threshold (e.g. -5°C)
boat/heating/cmd/mode → auto/manual/off
Example:
boat/heating/status/ring5 → "1" (ring 5 is on)
boat/heating/temperature/outside → "-8" (outside temperature)
ValveHeater/
├── README.md (EN/DE)
├── hardware/
│ ├── stl/
│ │ ├── heizring-1inch.scad
│ │ ├── heizring-2inch.scad
│ │ ├── heizring-1inch.stl
│ │ ├── heizring-2inch.stl
│ ├── electronics/
│ │ ├── boatopenio-extension-schematic.pdf
│ │ └── boatopenio-heizring-module.kicad
│ └── bom.md
├── firmware/
│ ├── arduino/
│ │ └── boatopenio-heizring-firmware.ino
│ └── mqtt-config.json.example
├── docs/
│ ├── installation.md
│ ├── configuration.md
│ ├── mqtt-topics.md
│ └── troubleshooting.md
└── examples/
└── boatos-dashboard-widget.json
Recommended material: ASA (heat resistant up to ~95-100°C, UV-resistant, weatherproof)
Alternative: PETG (easier to print, sufficient for normal operation)
Do not use: PLA (softens at ~60°C – too close to operating temperature)
Print parameters for snap ring:
- Layer Height: 0.2mm
- Infill: 20-30%
- Support: not needed
- Orientation: ring lies flat (width = Z-axis)
Important: The snap opening must be precise – fine-tune with sandpaper if needed, so the ring slides onto the pipe easily but sits rock solid.
- Works standalone without BoatOS
- With BoatOS: full dashboard integration
- Any boat with 12V onboard power
GNU General Public License v3 (GPL-3.0) – free to use, modify, distribute. Derivative works must also be licensed under GPL-3.0.
Logbook Without Posing – Volume 6: The Valve Heater
"Made by hand means knowing what's inside and keeping it affordable."
📖 Book series on Amazon · 🔧 BoatOS · ⚡ BoatOpenIO
