adapter
tool
hose
repair
drain
maintenance
bsp
boiler
bspp

4
0
This adapter is designed to mount directly onto the pressure relief / non-return valve of a boiler using a 1/2” BSPP thread.
Its purpose is to unlock the valve and speed up boiler draining, making disassembly and maintenance much easier and cleaner.
The bottom of the adapter is sized to accept a standard garden hose, allowing you to safely route the water to a sink, drain, or outside area.

⚙ How It Works
The adapter features an internal pin that deactivates the safety valve, allowing water to flow freely out of the boiler through the connected hose.

You can use PTFE tape on the threads to prevent unwanted leaks during draining.
🛠 Printing Recommendations
- Material: PETG
- Layer Height: 0.15 mm
- Infill: 100%
- Brim: YES
- Support: NO
🚰 Usage Instructions & Safety Notes
- Let the water cool down before draining the boiler.
- The internal diameter of the garden hose must be 15 mm.
- To allow proper water flow, open a hot water tap or disconnect the hot water outlet.
For a cleaner and safer workflow, it is recommended to install two small shut-off valves:
- One on the cold water inlet
One on the hot water outlet
This allows you to disconnect hoses with the valves closed, mount the adapter, and avoid water spills.
This adapter makes boiler maintenance faster, safer, and much more controlled, no more messy draining or struggling with the relief valve.

Sponsor ❇
Thank you to PCBWay for reaching out and sponsoring this project:

If your printer isn’t capable of printing technical materials that can withstand high temperatures or if you simply want to build this project using premium materials and finishes, PCBWay can come to your rescue!
PCBWay supports me in the development of my projects and specializes in PCB, PCBA, CNC, and 3D Printing, and has (in my experience) the best support & the widest amount of options for manufacturing as compared to other services. I highly recommend it.
Their 3D printing services offer a very wide selection of processes including SLA, DLP, FDM, SLM, SLS, PJ, VC, and materials including metals and nylon.
The ordering process is very quick, just upload the design file and select the parameters.
The same print is uploaded on PCBWay+ Community, you can go here and get the print with one click.
👉 If you're new there don't forget to use this link for 5$ discount https://pcbway.com/g/3BjHD9
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Originality of the Model
The author declares that this work is their personally original model
This model is licensed under the following terms:
This work is licensed under a Standard Digital File License. Digital files have a strict non-commercial, personal use only license.
You shall not share, sub-license, sell, rent, host, transfer, or distribute in any way the digital file or 3D printed versions of this object, nor any other derivative work of this object in its digital or physical format (including remixes of this object). You can not host these files on other digital platforms, web stores or cloud repositories. The objects may not be used in any way whatsoever in which you charge money, collect fees.
Models(1)
Boiler Drain Adapter_C.3mfDesigner17.74 MB
2026-03-16


