Water coming from the wrong outlet, from two outlets at once, or dripping somewhere you haven't selected, points to the diverter core no longer sealing cleanly between positions rather than being stuck. A worn or split core lets water past even when it looks like it's fully switched.
Applies to: shower cabins and steam showers
INTRO HERE
Compatible with many shower cabin brands including
Quick diagnosis
If your shower cabin is showing these symptoms:
- Two outlets run at the same time when only one should
- Water dribbles from the overhead or body jets after you've switched to the handset
- Selector feels like it's moved to the right position but the wrong outlet still runs
- Problem is worse just after switching and settles down after a few seconds
- Selector has always felt slightly imprecise, even when new
Likely causes, most likely first
- Diverter core worn or split internally. The core’s seals stop sealing fully between positions as they age, so water crosses over between outlets instead of switching cleanly.
- Core not seated fully in the valve body. If it’s been out for cleaning or replacement recently and wasn’t pushed home properly, it won’t seal correctly even though it looks fitted.
- Selector knob’s indicator doesn’t match the core’s actual position. If the grub screw has slipped, the knob can point at one outlet while the core is actually sitting somewhere between positions.
Likely cause
This is different from a selector that won't switch at all; here the core is moving, it's just not sealing between positions any more, and that's wear rather than a jam.
Check this first
- Check the knob’s indicator lines up with a position you can feel it click into, not somewhere in between
- Run each outlet in turn and note exactly which others leak, since that narrows down whether it’s the core or just the knob’s position
- If the core has been replaced or removed recently, check it’s been pushed fully home rather than just resting in the valve body
- Some dripping from the overhead shower head just after use is often leftover water draining out of the roughly 150cm feed hose, and is normal … only worth chasing if it’s more than a dribble or doesn’t stop
Which part fits your cabin
| Brand | Model / range | Part | Confidence |
|---|---|---|---|
| Insignia | 40 models across the Diamond, ECO, ES, GT, INS, Monochrome, Noire, Platinum, Premium and SportsFitness ranges | 33mm 3-Way Diverter Core Cartridge (SPS 040) | Listed on Insignia’s own parts pages |
| Vidalux | SS (Steam) range, Essence, Essence Classic | 33mm 3-Way Diverter Core Cartridge (SPS 040); the 4-way (SPS 090) and 5-way (SPS 042) cores fit the same range too | Checked against Vidalux’s own product records |
Cores for this fault are the same as the selector-won’t-turn page … it’s the same core, sealing rather than turning, that’s at issue. 4, 5 and 6-way versions exist for cabins with more switched outlets, matched by outlet count rather than by brand.
How to identify your part
Diverter cores come in 3, 4, 5 and 6-way versions depending on how many features your cabin switches between, but outlet count and barrel size don’t move together in a straight line. The 5-way core is actually smaller across the barrel than some 4-way cores, and there are two different 6-way barrel sizes. Match your old core’s outlet count AND its barrel diameter before ordering a replacement, since a core that’s slightly too small won’t seat properly even if it turns.
Parts that fix this problem
The following replacement parts usually fix this issue.
Not sure which replacement part you need? Send us a photo and we will help identify the correct replacement.
How to fix it
- Run each outlet in turn and note exactly which ones leak or run together
- Isolate the water and remove the full valve housing to reach the diverter core
- Check the core is pushed fully home in the valve body, not just resting against it
- If it’s seated correctly and still crosses over between outlets, replace the core rather than just reseating it
Also described as
- Steam shower
- Steam shower cabin
- Hydro massage shower
When to call a professional
Same as any job that needs the valve housing out; fine to do yourself if you're comfortable with it, otherwise a plumber can fit the new core while everything's already open.
