January 8, 2026
Description
A tool that holds the radiator bleed valve cap steady and directs water into a small cup while you turn the screw with a screwdriver. Designed for one-hand use, without making a mess.
Print instructions:
Assembly:
Glue the two printed parts together using standard super glue (cyanoacrylate).
Apply glue along the groove on the cap — on the sides and around the curve.
Press it onto the cup part and hold firmly until bonded.
If you have an activator, use it to speed up curing.
Important:
Use only when the radiator water is cold or lukewarm.
Avoid using it with hot water — you could get burned, and PLA may deform from heat.
Note:
After bleeding the radiators, don't forget to check the pressure in your system and, if necessary, top it up to the correct pressure.
Motivation to make this model:
When bleeding a radiator, the small plastic cap with the drain hole often starts turning as you use a screwdriver to open the valve. Once it moves, the water no longer drains where you expect — and since one hand is on the screwdriver and the other holds the bowl for the dripping water, you suddenly need a third hand to keep that cap steady. This simple tool was created to solve exactly that problem: it holds the cap firmly in place and channels the water safely into a small cup.
Onshape model:
https://cad.onshape.com/documents/5fc53ca6468d6ec761e8f8df/v/ae9a58f848f4625137548862/e/ec76cdef746a95a58c492261
Youtube video how to use:
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License:
Creative Commons — Attribution — Noncommercial — Share Alike
ByPS128
