GROHE 37105K00 WC inlet and outlet connecting set for concealed cisterns
Product description
Overview
If you’re fitting (or fixing) a wall-hung WC with a concealed cistern, the plumbing details matter more than most people expect. The GROHE 37105K00 WC inlet and outlet connecting set is designed to bridge the WC inlet/outlet requirements with a 45 mm pipe approach, using compatible components for a cleaner, in-wall setup.
On paper, it’s a straightforward “get the connections right” part: a connecting pipe (45 mm diameter) plus chrome-finished caps intended to sit neatly around the WC fixing bolts and waste pipe area. It’s not the kind of item you buy for fun—more the sort that keeps the install tidy and reduces the chance of mismatched plumbing during a concealed cistern job.
What it’s for (and where it fits)
This connecting set is aimed at concealed cistern installations for wall-hung WCs. The description specifically notes that it is for concealed cisterns and that it should not be used with Adagio / Dallux.
It includes: - A connecting pipe for the WC inlet/outlet, listed as 45 mm diameter - Two chrome finished caps for WC fixing bolts and the waste pipe
The waste pipe detail is given as 110 mm wide and 150 mm long, which is a useful clue when you’re trying to confirm whether this will match the space you’ve got in the frame.
It’s also worth noting that this comes with a 5 Year manufacturer’s warranty, which is often the main reason to stick with the branded connecting components instead of improvising with generic alternatives.
Key features and why they matter
Where this set earns its place is in the boring-but-important parts of a concealed WC installation:
- 45 mm connecting pipe for the WC run: if your install calls for this diameter, having the correct part reduces guesswork.
- Chrome-finished caps: they’re meant to finish off around the fixing bolts and waste pipe area, so the visible parts look intentional rather than “temporary”.
- Dimensions for the waste pipe area: 110 mm wide and 150 mm long is the kind of information installers rely on when aligning parts behind the wall.
A small limitation to keep in mind: it’s clearly positioned for certain concealed cistern setups, and the note about not being compatible with Adagio / Dallux means you’ll want to check your system before ordering.
The essential technical details (quick check)
- Connecting pipe: 45 mm diameter
- Waste pipe area: 110 mm wide and 150 mm long
- Finish: chrome finished caps
- Warranty: 5 Year manufacturer’s warranty
Pros, cons, and likely buyer mindset
What stands out is that it’s not a random accessory—it's an installation-focused connecting set with defined dimensions and a branded warranty behind it. If you’re trying to complete a concealed cistern wall-hung WC setup neatly, having the specified connecting pipe and matching caps can make the process smoother.
Where it may not suit everyone is if your cistern system is one of the ones it explicitly excludes (Adagio / Dallux). Also, if you’re only dealing with a minor cosmetic issue, you might not need a full inlet/outlet connecting kit—depending on what’s actually gone wrong.
If you’re choosing between buying the correct part versus trying to adapt something else, this is the sort of purchase that usually wins when alignment and finishing are the priority.
Practical usage example
Imagine you’ve mounted your wall-hung WC and concealed cistern, and you now need to finalise the visible connection points for the fixing bolts and the waste pipe area behind the pan. With a connecting set like this, you’d typically use the 45 mm connecting pipe as the link for the inlet/outlet run, then position the chrome-finished caps so the fixing and waste pipe openings look finished once the WC is seated.
That “last-mile” step is where having the right dimensions and the right type of cap tends to save time.
Who should buy it (and who should skip it)
It’s a sensible pick if you’re: - working on a concealed cistern installation for a wall-hung WC - trying to match a setup that uses the 45 mm diameter connecting pipe - aligning around a waste pipe area around 110 mm wide and 150 mm long - looking for a parts-based approach backed by a 5 Year manufacturer’s warranty
It’s not the best match if you: - have an installation based on Adagio / Dallux, because the description says it’s not for those systems - need something unrelated to the inlet/outlet connecting and finishing caps (for example, you only require a different type of fitting)
Buying verdict
Is it worth it?
For most concealed cistern, wall-hung WC installs that need a properly specified inlet/outlet connecting set, the GROHE 37105K00 looks like a “yes, if the measurements and system compatibility line up” type of purchase. The inclusion of the connecting pipe (45 mm diameter) and chrome-finished caps for the fixing bolts and waste pipe area makes it purpose-built rather than a generic workaround.
You should be careful not to assume it fits every concealed cistern setup, though—the note about not being for Adagio / Dallux is the big check before you buy. If that compatibility doesn’t apply to you, this is the sort of connecting kit where paying attention to fit and dimensions is likely to pay off.
Quick FAQ
Is this connecting set only for wall-hung WCs?
The description frames it as a connecting pipe set for a wall-hung WC with concealed cisterns.
What diameter is the connecting pipe?
It’s listed as 45 mm diameter.
Does it fit all concealed cistern systems?
Not necessarily. It specifically says it is not for Adagio / Dallux, so it depends on your cistern system.
What size is the waste pipe area it’s intended for?
The waste pipe is described as 110 mm wide and 150 mm long.