instant water heater under sink
Skip itPrices mostly outside the sweet spot ($58.22–$969.90) — this niche doesn't clear our bar today.
Market size
Great$1.3M$1.3M/yr · 292K searches
Quality gap
Great4.2★avg incumbent rating — lower means beatable quality
Competition
Great40%top-5 click share — an open shelf
Review moat
Good873.13avg incumbent reviews — the moat a new listing must climb
Brand share
Okay80%top-5 brand share — brands hold most of the demand
Avg price
Okay$340.10avg listing price — sweet spot $15–$100
Conversion
Bad1.3%search→purchase rate — share of searches ending in a sale
Growth
Bad-23.1%90-day search growth — must beat 0% to launch
Returns
Bad8.8%return rate — above 5% kills the launch gate
Price range
Bad$58.22–$969.90cheapest to priciest tracked listing — scored on the share inside $15–$100
According to Flapen's Amazon United States niche tracking, instant water heater under sink is a $1.3M/yr Amazon United States market (292K searches/yr). The top 5 brands hold 80% of demand. Demand peaks in Jan–Dec. Verdict: Skip it — 45/100.
Data updated Jul 29, 2026 · scored weekly · How we score niches
instant water heater under sink market data
- Units sold / yr
- 4K–5K
- avg 100–250/product
- Revenue / yr
- $1.4M–$1.7M
- units × avg price
- Conversion rate
- 1.3%
- Avg BSR
- #193
- Page quality
- 0%
- Prime
- 96%
- Sponsored
- 67%
- Out of stock
- 5.9%
- Avg brand age
- 36 months
- Avg seller age
- 166 days
Competition & brand share
Clicks spread well past the top 5 (40% combined) — an open shelf where new products get seen.Brands
15 falling
Sellers
110
Top-5 brand share
80%
Top 20: 100%
Top-5 click share
40%
Top 20: 74%
Open market
17%
- Rheem47%
- EcoSmart19%
- WINTEMP6%
- CAMPLUX ENJOY OUTDOOR LIFE4%
- thermomate4%
- LECLOC3%
- Open — no brand owns it (9 brands, 17%)
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -23.1% search growth over the last 90 days.Peak months: Jan, Dec · busiest ÷ quietest = 1.9×
Top instant water heater under sink search terms
- rheem tankless water heater26K/yr
- rheem tankless water heater electric47K/yr
- electric tankless water heater 240v28K/yr
- ecosmart tankless water heater30K/yr
- rheem water heater26K/yr
- eco smart tankless hot water heater15K/yr
- 120v tankless water heater12K/yr
- rheem12K/yr
- whole house tankless water heater11K/yr
- electric tankless water heater whole house9K/yr
Top instant water heater under sink 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.
All 24 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Rheem 18kW 240V Tankless Electric Water Heater Gray
Rheem$409.474.2★4,064 rev
Rheem 11kW 240V Tankless Electric Water Heater
Rheem$244.084.2★4,064 rev
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater Gray
Rheem$480.694.2★4,064 rev
EcoSmart ECO 27 Electric Tankless Water Heater 27 KW at 240 Volts 112.5 Amps with Patented Self Modulating Technology 17 x 17 x 3.5 White
EcoSmart$481.784.2★3,053 rev
EcoSmart ECO 18 Electric Tankless Water Heater 18 KW at 240 Volts with Patented Self Modulating Technology 17 x 14 x 3.5 White
EcoSmart$377.274.3★2,441 rev
Newest
by launch date
LECLOC Mini Instant Under Sink Tankless Water Heater 120V 3kW Plug In LED Digital Display with Big Knob IPX4 Multiple Safety Features 30-55 Thermostatic Single Point of Use Electric Water Heater
LECLOC$177.0620 rev
LECLOC Mini Tankless Instant Water Heater Under Sink 3000W 120V Plug In LED Digital Display with Big Control Knob IPX4 Multiple Safety Features 30-55 Thermostatic On Demand Electric Water Heater
LECLOC$175.7912 rev
CAMPLUX Tankless Water Heater Electric 120V 3500W Point of Use Instant Hot Water Heater Save Space for Sink Wall Mounted LED Digital Display CSA Certified
CAMPLUX ENJOY OUTDOOR LIFE$114.60681 rev
CAMPLUX Tankless Water Heater Electric 120V 4500W Point of Use Instant Hot Water Heater Save Space for Sink Wall Mounted LED Digital Display CSA Certified
CAMPLUX ENJOY OUTDOOR LIFE$123.21681 rev
CAMPLUX Tankless Water Heater Electric 6kW(TE06) at 240 Volts Point of Use Instant Hot Water Heater CSA Approved with Temperature Display Under Sink Self Modulating Technology White
CAMPLUX ENJOY OUTDOOR LIFE$128.605 rev
Trending
90-day click momentumLECLOC Mini Instant Under Sink Tankless Water Heater 120V 3kW Plug In LED Digital Display with Big Knob IPX4 Multiple Safety Features 30-55 Thermostatic Single Point of Use Electric Water Heater
LECLOC$177.064.2★
LECLOC Mini Tankless Instant Water Heater Under Sink 3000W 120V Plug In LED Digital Display with Big Control Knob IPX4 Multiple Safety Features 30-55 Thermostatic On Demand Electric Water Heater
LECLOC$175.792.2★
CAMPLUX Tankless Water Heater Electric 120V 4500W Point of Use Instant Hot Water Heater Save Space for Sink Wall Mounted LED Digital Display CSA Certified
CAMPLUX ENJOY OUTDOOR LIFE$123.214.2★
CAMPLUX Tankless Water Heater Electric 120V 3500W Point of Use Instant Hot Water Heater Save Space for Sink Wall Mounted LED Digital Display CSA Certified
CAMPLUX ENJOY OUTDOOR LIFE$114.604.2★
CAMPLUX Tankless Water Heater Electric 6kW(TE06) at 240 Volts Point of Use Instant Hot Water Heater CSA Approved with Temperature Display Under Sink Self Modulating Technology White
CAMPLUX ENJOY OUTDOOR LIFE$128.604.8★
What buyers say about instant water heater under sink
What buyers praise and complain about, mined from review topics.What buyers love
“Quick easy install and set up”
“The build quality also stands out”
“Excellent value”
“Works well for our needs”
“Its a great choice for saving space”
“The compact size saves space”
“Useful and works fast”
“Nice sleek appearance”
“It perfectly fits into tiny spaces”
“fulfills what it promises”
What buyers complain about
“Does not last”
“Bad quality control on their part = a useless product”
“Extremely difficult to install”
“Will not function”
“Wireing is expensive”
“Small size”
“Not recommended the description is no very clear”
“Not a very detailed operation manual”
“it had been leaking a while it appears”
“It does not maintain water temperature well, either”
Top return reasons
Common questions
- Is instant water heater under sink profitable to sell on Amazon United States?
- The niche generates $1.3M/yr across 46 tracked products. 13 of 14 products launched in the last 360 days are still selling. 90-day search growth is -23.1%. Flapen's verdict: Skip it (45/100).
- How competitive is the instant water heater under sink niche?
- 15 brands and 110 sellers compete. The top 5 products take 40% of clicks and top 5 brands hold 80% of demand.
- What do buyers complain about in instant water heater under sink?
- Top complaints mined from reviews: Durability, Quality-Overall, Assembly/Installation. The return rate is 8.8% — above our launch gate.
- When does demand for instant water heater under sink peak?
- Demand peaks in Jan–Dec; the busiest month runs 1.9× the quietest.
- What does it cost to enter the instant water heater under sink niche?
- Listings span $58.22–$969.90; the average listing price is $340.10 (sweet spot $15–$100). The average incumbent carries 873 reviews — the moat a new listing must climb.