---
title: "Cistern Fill Valve — £91K/yr Amazon UK Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/uk/business-industry-science/cistern-fill-valve"
last_updated: "2026-07-31T22:28:58.981Z"
locale: en
meta:
description: "Niche score 38/100 · £91K/yr market · 127K searches/yr · £9.84 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 38/100 · £91K/yr market · 127K searches/yr · £9.84 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Cistern Fill Valve — £91K/yr Amazon UK Niche (2026) - Flapen"
---
# **cistern fill valve**
**Skip it**
Brand-locked demand (top 5 brands take 96% of clicks) — this niche doesn't clear our bar today.
Market size 23Growth 28Conversion 76Competition 22Returns 76Price range 10Avg price 32Brand share 9Review moat 74Quality gap 50
**Conversion**
**Great****7.3%**
search→purchase rate — share of searches ending in a sale
**Returns**
**Great****2.0%**
return rate — above 5% kills the launch gate
**Review moat**
**Good****541.73**
avg incumbent reviews — the moat a new listing must climb
**Quality gap**
**Good****4.5★**
avg incumbent rating — lower means beatable quality
**Avg price**
**Okay****£9.84**
avg listing price — sweet spot $15–$100
**Growth**
**Okay****+2.4%**
90-day search growth — must beat 0% to launch
**Market size**
**Bad****£91K**
£91K/yr · 127K searches
**Competition**
**Bad****73%**
top-5 click share — a locked-up shelf
**Price range**
**Bad****£4.23–£16.19**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Brand share**
**Bad****96%**
top-5 brand share — brand-locked demand
According to Flapen's Amazon United Kingdom niche tracking, cistern fill valve is a £91K/yr Amazon United Kingdom market (127K searches/yr). The top 5 brands hold 96% of demand. Verdict: Skip it — 38/100.
Data updated Jul 21, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **cistern fill valve market data**
- **Units sold / yr**
- **8K–10K**
- avg 250–500/product
- **Revenue / yr**
- **£79K–£98K**
- units × avg price
- **Conversion rate**
- **7.3%**
- **Avg BSR**
- **#41**
- **Page quality**
- **0%**
- **Prime**
- **93%**
- **Sponsored**
- **87%**
- **Out of stock**
- **1.1%**
- **Avg brand age**
- **39 months**
- **Avg seller age**
- **166 days**
## **Competition & brand share**
The top 5 products capture 73% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**7 **▼falling
**Sellers**
**53**
**Top-5 brand share**
**96%**
Top 20: 100%
**Top-5 click share**
**73%**
Top 20: 100%
**Open market**
**2%**
- Fluidmaster33% - VeeBath31% - Fzosinou14% - PlumbEZ10% - Hulthor8% - Taps2Traps2% - Open — no brand owns it (1 brand, 2%)
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +2.4% search growth over the last 90 days.
3K2KSpike '24Spike '25Spike '26 seasonSepDecMarJunAugNovMarMay
No pronounced peak months · busiest ÷ quietest = 1.4×
[**Open Trend **](https://flapen.com/research/uk/business-industry-science/cistern-fill-valve/trend)
## **Top cistern fill valve search terms**
- **toilet fill valve**24K/yr-4.2%6.1% conv. - **cistern fill valve**15K/yr-3.6%5.7% conv. - **fluidmaster flush valve**12K/yr+22.4%4.2% conv. - **toilet cistern fill valve**13K/yr+12.1%5.2% conv. - **bottom entry toilet fill valve**8K/yr+16.7%7.4% conv. - **toilet inlet valve**7K/yr+24.3%6.1% conv. - **toilet fill valve bottom entry**8K/yr-12.5%8.5% conv. - **toilet float valve**7K/yr+4.6%4.5% conv. - **toilet inlet valve bottom entry**7K/yr-10.8%6.2% conv. - **fluidmaster**6K/yr+5.5%3.0% conv. [**All search terms **](https://flapen.com/research/uk/business-industry-science/cistern-fill-valve/search-terms)
## **Top cistern fill valve products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%10%£9K20%£18K30%£27K40%£37K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 15 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**VeeBath Toilet Inlet Valve Bottom Entry Inlet Float Valve 1/2 inch**VeeBath**£8.55**4.5★3,079 rev](https://www.amazon.co.uk/dp/B010CC8IOA) [2**Fluidmaster PRO45B Fill Valve with Brass Shank - Black**Fluidmaster**£14.70**4.6★1,635 rev](https://www.amazon.co.uk/dp/B004O8601M) [3**Toilet Flush System Replacement Adjustable Bottom Entry Toilet Fill Valve High Pressure Cistern Fill Valve - Prevents Backflow for Home Bathroom Tank Maintenance Water Saving**Fzosinou**£8.30**4.4★13 rev](https://www.amazon.co.uk/dp/B0G64THNQ9) [4**Hulthor Bottom Entry Toilet Fill Valve Toilet Inlet Valve Replacement 1/2 UK Brass Thread Adjustable 8-12 Compact Cistern Float**Hulthor**£12.37**4.8★85 rev](https://www.amazon.co.uk/dp/B0F7N44SYT) [5**PlumbEZ Adjustable Bottom Entry Toilet Fill Valve with UK Brass Threads - Cistern Fill Valve with Delayed Fill Quiet Operation Telescopic Height 8-12 & Water Saving Filter - Brass Threads**PlumbEZ**£11.89**4.9★55 rev](https://www.amazon.co.uk/dp/B0F14DQSPQ)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**Toilet Flush System Replacement Adjustable Bottom Entry Toilet Fill Valve High Pressure Cistern Fill Valve - Prevents Backflow for Home Bathroom Tank Maintenance Water Saving**Fzosinou**£8.30**13 rev7mo ago](https://www.amazon.co.uk/dp/B0G64THNQ9) [**PlumbEZ Universal Side Entry Toilet Cistern Fill Valve with Adjustable Float Arm - 1/2 Toilet Inlet Valve Side Entry Fill Ball Valve with Float**PlumbEZ**£8.55**48 rev1y ago](https://www.amazon.co.uk/dp/B0FGY8FQ5Y) [**PlumbEZ Toilet Cistern Fill Valve Bottom Entry with Float - 1/2 Toilet Fill Valve with Adjustable Arm | Ballcock for Toilet Cistern with Ball Float**PlumbEZ**£9.86**35 rev1y ago](https://www.amazon.co.uk/dp/B0FGY8W95P) [**Hulthor Bottom Entry Toilet Fill Valve Toilet Inlet Valve Replacement 1/2 UK Brass Thread Adjustable 8-12 Compact Cistern Float**Hulthor**£12.37**85 rev1y ago](https://www.amazon.co.uk/dp/B0F7N44SYT) [**PlumbEZ Adjustable Bottom Entry Toilet Fill Valve with UK Brass Threads - Cistern Fill Valve with Delayed Fill Quiet Operation Telescopic Height 8-12 & Water Saving Filter - Brass Threads**PlumbEZ**£11.89**55 rev1y ago](https://www.amazon.co.uk/dp/B0F14DQSPQ)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Toilet Flush System Replacement Adjustable Bottom Entry Toilet Fill Valve High Pressure Cistern Fill Valve - Prevents Backflow for Home Bathroom Tank Maintenance Water Saving**Fzosinou**£8.30**4.4★**▲ 175%**](https://www.amazon.co.uk/dp/B0G64THNQ9) [**W.C. Fill Valve Bottom Entry**Fluidmaster**£5.61**4.3★**▲ 64%**](https://www.amazon.co.uk/dp/B0087P2AKS) [**W.C. Fill Valve Side Entry**Fluidmaster**£4.38**4.3★**▲ 45%**](https://www.amazon.co.uk/dp/B003BNPD8M) [**Fluidmaster PRO550LC Pro Button Cable Dual Flush Valve 550mm Long Dual Flush Cable Valve for Concealed Cisterns Top or Front Push Buttons 1 & 2 Outlet Fit White**Fluidmaster**£16.19**4.7★**▲ 44%**](https://www.amazon.co.uk/dp/B07PYXZNY1) [**PlumbEZ Adjustable Bottom Entry Toilet Fill Valve with UK Brass Threads - Cistern Fill Valve with Delayed Fill Quiet Operation Telescopic Height 8-12 & Water Saving Filter - Brass Threads**PlumbEZ**£11.89**4.9★**▲ 25%**](https://www.amazon.co.uk/dp/B0F14DQSPQ)
**~~View all trending →~~**
## **What buyers say about cistern fill valve**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**21%
*“Easy fit”*
**Quality-Overall**16%
*“Excellent product”*
**Assembly/Installation**11%
*“Easy to install and set up”*
**Advertised Vs Actual Product**9%
*“Perfect works as it should”*
**Value For Money**9%
*“Decent value”*
**Ease Of Use**5%
*“Easy to use”*
**Adjustability/Rotatability/Reclining**5%
*“adjustable”*
**Efficiency**4%
*“does the job perfectly”*
**Leak-Proof**2%
*“Hopefully, there is no leakage”*
**Noise Level**2%
*“is much quieter”*
### **What buyers complain about **
**Size-Overall**12%
*“It was smaller than the original broken one too”*
**Leak-Proof**10%
*“Leaked”*
**Noise Level**9%
*“does seem noisy compared to my previous top fill one”*
**Quality-Overall**8%
*“Bad quality”*
**Durability**6%
*“as none of them seem to last more than a couple of years”*
**Defective Material/Parts**5%
*“Product arrived broken”*
**Functionality-Overall**5%
*“Does not work”*
**Thickness**3%
*“thicker than original”*
**Water Resistance**3%
*“Sadly this item will not stop letting in the water so I have to manually turn the water off”*
**Material Quality**2%
*“The only reason Im giving 4 stars instead of 5 is that the plastic feels a little lightweight”*
### **Top return reasons **
**Size-Overall**49%
**Compatibility-Overall**14%
**Defective Material/Parts**11%
**Functionality-Overall**5%
**Maintenance And Repair**3%
**Leak-Proof**3%
**Advertised Vs Actual Product**2%
**Water Resistance**1%
**Quality-Overall**1%
**Product Condition**1%
## **Common questions**
- **Is cistern fill valve profitable to sell on Amazon United Kingdom?**
- The niche generates £91K/yr across 15 tracked products. 1 of 1 products launched in the last 360 days are still selling. 90-day search growth is +2.4%. Flapen's verdict: Skip it (38/100).
- **How competitive is the cistern fill valve niche?**
- 7 brands and 53 sellers compete. The top 5 products take 73% of clicks and top 5 brands hold 96% of demand.
- **What do buyers complain about in cistern fill valve?**
- Top complaints mined from reviews: Size-Overall, Leak-Proof, Noise Level. The return rate is 2.0%.
- **When does demand for cistern fill valve peak?**
- Demand is steady year-round — the busiest month runs 1.4× the quietest.
- **What does it cost to enter the cistern fill valve niche?**
- Listings span £4.23–£16.19; the average listing price is £9.84 (sweet spot $15–$100). The average incumbent carries 542 reviews — the moat a new listing must climb.
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