Under Sink Water Heaters

If you can’t connect to a mains water supply to get your hot water, an under counter hot water heater is a great alternative. Eliminating the need for complex pipe installations, these instant hot water heaters run off electricity, sitting under your sink for a neat finish.

We’ll help you find an under sink water heater

Under sink hot water heaters are a brilliant option for home bathrooms and kitchens. They can easily be concealed, either by a vanity unit or by being tucked away under your basin, thanks to their compact design. What’s more, these electric hot water heaters are efficient and, as they are unvented, can be connected straight to a mains water supply, providing instant heating at a strong pressure. If you have more than one sink or water outlet in your room, take a look at our Powerstream under counter water heaters - these can be used with up to two hand basins and achieve a temperature of 29 - 54°C.

Whether it’s for residential or commercial use our instant hot water heaters, or electric under sink heaters, promise low prices and excellent quality - find yours at Plumbworld now!

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Redring Powerstream 9.5kW Electric Water Heater - Instantaneous

4.9

15 ratings

£129.50 inc
VAT

Save £18.26 | Was £147.76

Redring Powerstream 10.8kW Electric Water Heater - Instantaneous

5.0

4 ratings

£156.60 inc
VAT

Save £25.39 | Was £181.99

Redring Powerstream 12kW Electric Water Heater - Instantaneous

4.9

9 ratings

£152.00 inc
VAT

Save £22.62 | Was £174.62

Triton InstaFlow 5.4kW Electric Water Heater

5.0

1 rating

£123.78 inc
VAT

Save £15.84 | Was £139.62

Triton InstaFlow 7.7kW Electric Water Heater

5.0

2 ratings

£140.26 inc
VAT

Save £34.74 | Was £175.00

Triton InstaFlow 10.1kW Electric Water Heater

4.8

4 ratings

£148.63 inc
VAT

Triton Instaflow 1.5kW Electric Water Heater - 5L Stored

5.0

8 ratings

£101.57 inc
VAT

Save £15.63 | Was £117.20

Triton Instaflow 2kW Electric Water Heater - 10L Stored

5.0

9 ratings

£124.06 inc
VAT

Triton Instaflow 2kW Electric Water Heater - 15L Stored

5.0

9 ratings

£125.98 inc
VAT

What is the difference between instantaneous and stored under sink water heaters, and which is best for my sink?

Instantaneous heaters heat water on demand and give a continuous supply while you run the tap, so they suit regular use at a basin or kitchen sink; examples here include Redring Powerstream 9.5kW–12kW and Triton InstaFlow 5.4–10.1kW. Stored heaters keep a small buffer of hot water and work well for very occasional use or where your electrical supply limits kW, but they can run out if demand is high. If you want steady hot water and stronger flow for washing up or two basins, an instantaneous high‑kW unit is usually the better choice. Choose a stored unit only for low, intermittent demand such as a cloakroom basin.

Will an under sink heater give me good water pressure and temperature at the tap?

Yes, these under counter heaters are unvented and can be connected straight to the mains, so they can deliver strong pressure similar to your cold supply. The achievable temperature depends on the heater's power: Powerstream models can reach about 29–54°C, while higher kW models (10.8–12kW) will maintain higher temperatures at greater flow rates than low‑powered stored units. If you want hotter water while filling or rinsing, aim for a higher kW instantaneous model rather than a small stored heater.

Can one under sink heater serve two basins or multiple outlets?

Some instantaneous units are designed for two outlets; the Redring Powerstream range is suitable for up to two hand basins. Most other instantaneous models are intended for a single outlet, and stored heaters with 5–15 litres aren't suitable for simultaneous multiple users. If you plan to run two taps at once, choose a Powerstream or a high‑kW instantaneous model and check the product's stated number of outlets.

How do I choose the right kW or litre capacity for my needs?

Match the kW to how much flow and temperature you need: small cloakroom basins can work well with low kW stored units such as a 1.5–2kW, 5–10L model, while kitchen sinks or shared basins benefit from 5.4–12kW instantaneous models. if you want to rinse pans or run two basins, a 9.5–12kW Powerstream will give noticeably better heat and flow than a 2kW stored unit. Also factor in how many outlets you'll use at once and whether you prefer on‑demand heating or a small stored buffer.

How do I make sure the unit will fit under my sink and be concealed neatly?

These heaters are compact so they hide easily behind a vanity, but you must measure your cupboard space first, available models range in height from about 160mm to 406mm, width from 136mm to 385mm and depth from 72mm to 332mm. If your cupboard is shallow, look for the slim depths around 72–81mm; for a very small cloakroom a 160mm‑high stored 5L unit might be perfect. Leave a little clearance for plumbing connections and access to controls when you position the heater.

Filter By 9 results

Filter By 9 results

What is the difference between instantaneous and stored under sink water heaters, and which is best for my sink?

Will an under sink heater give me good water pressure and temperature at the tap?

Can one under sink heater serve two basins or multiple outlets?

How do I choose the right kW or litre capacity for my needs?

How do I make sure the unit will fit under my sink and be concealed neatly?

Filter By
9 results

Filter By
9 results