The Pre-Purchase Bidet Checklist: 8 Things to Confirm Before You Buy
- Most bidet buying mistakes come from skipping one of a handful of simple checks beforehand.
- Water pressure, toilet shape, and power access matter more than any feature list.
- WRAS approval and Fluid Category 5 backflow protection aren't optional extras — they're the legal baseline.
- Five minutes of checking saves a returned product or a non-compliant installation.
Why a Checklist Beats Another Buying Guide
Most bidet buying guides walk through the same general territory — types, costs, pros and cons — without ever landing on the handful of specific checks that actually prevent a wasted purchase. This is the shorter, more practical version: eight things to confirm before you click buy, in the order that actually matters.
1. Test Your Actual Water Pressure
Don't assume — measure it. Fill a jug for exactly 6 seconds with your bathroom tap fully open, then multiply the litres collected by 10 to get your flow rate in litres per minute. Below 10 LPM suggests a lower-pressure system, common in older properties on gravity-fed supply. If that's you, look specifically for a sprayer rated for low-pressure systems rather than assuming any model will perform the same.
2. Check Your Toilet Shape
Round and elongated bowls aren't interchangeable for seat attachments. Measure your existing seat or check the manufacturer's spec sheet against your toilet's actual dimensions before ordering — this is the single most common reason for a returned bidet seat.
If you're between sizes or unsure about toilet shape, a handheld sprayer sidesteps this entirely — it doesn't need to match your toilet's dimensions at all, since it's not replacing the seat.
3. Confirm Power Access — Realistically
If you're considering an electric seat, check not just whether there's a socket nearby, but whether it's positioned outside UK bathroom electrical safety zones. Under Part P of the Building Regulations and BS 7671 wiring standards, sockets cannot be installed within certain zones around a bath or shower — typically within 3 metres of a bath or shower basin unless the socket is specifically rated for zone use. A socket that exists isn't automatically a socket you can safely use for this purpose — get an electrician's view before buying a product that then can't be safely wired where you planned.
4. Look for WRAS Approval — Specifically for Backflow Protection
Bidets and shattafs are classified as the highest-risk backflow category in UK Water Supply (Water Fittings) Regulations 1999 — Fluid Category 5 — which means a basic check valve is never sufficient. WRAS approval confirms the product has genuine, independently tested backflow protection built in. Don't substitute a generic product without it regardless of price difference; non-compliance is a breach of water fitting regulations and can affect insurance coverage.
5. Work Out Your Actual Savings, Not a National Average
The average UK household spends £100–£150 per year on toilet paper; a family of four can spend £120–£180 or more depending on brand and usage. Check a recent receipt for your own monthly roll count and multiply it out. That figure — not a generic estimate — tells you how quickly a given model genuinely pays for itself. Most households reducing paper use by 70–80% after switching recover the cost of a handheld sprayer within two to four months.
6. Decide Cold-Only or Warm — Honestly
Cold mains water (typically 10–15°C in a UK home) is fine for most people once they're used to it, and it's the simplest, cheapest option with the fewest things to go wrong. Warm water means either an electric seat with a heater (extra cost, needs power) or a mixer connection to your hot supply (more complex plumbing). Be honest about whether warmth genuinely matters to you before paying extra for it.
7. Check the Build Materials
Stainless steel or solid brass resists corrosion and limescale far better than chrome-plated plastic or zinc alloy, particularly in hard-water areas like much of London, the South East, and East Anglia. It's a quick detail to check on a spec sheet and a significant factor in whether a sprayer lasts a decade or needs replacing within a couple of years.
8. Know Who's Installing It Before You Order
A basic handheld sprayer or non-electric seat is genuinely DIY-friendly for most people — turning off the water, fitting a T-connector, and reconnecting takes around 20–30 minutes with a spanner. An electric seat needing new wiring is a different category of job entirely and should factor in an electrician's time and cost from the outset, not as an afterthought once the product has arrived.
The Checklist, All Together
| Check | Why it matters |
|---|---|
| Water pressure (jug test) | Weak spray on low-pressure systems if ignored |
| Toilet shape | Most common reason for seat attachment returns |
| Power socket location | Electrical safety zones under Part P / BS 7671 |
| WRAS / Fluid Category 5 | Legal backflow requirement — non-negotiable |
| Your own paper spend | Real payback period, not a national average |
| Cold vs warm water | Biggest single price and complexity factor |
| Build material | Longevity in hard-water areas |
| Installer (you or a pro) | Budget and timeline accuracy |
Work through these eight in order before you buy, and most of the common bidet-buying mistakes simply don't happen — no wrong-shaped seat, no weak spray, no compliance gap to untangle after the fact.