Instant Water Heaters

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Heater Shop's instant water heaters are compact in size so that they can fit in almost any location. Using only a cold water supply and an electrical connection, these products are ideal for homes and businesses that need a consistent and reliable source of hot water. Our instantaneous water heaters offer a range of kilowatt options and sizes. Our brands include Stiebel Eltron Water Heaters and Rointe Water Heaters and we have a wide variety suit your needs. This includes under sink instant water heaters.

If you need any help or further information about any of our tankless water heating products, please call our customer service team on 01473 276686 where one of our experts will be on hand to help.

Instant Water Heaters

Instant water heaters are ideal for properties with low hot water requirements or in more remote areas of the home such as the garage, outbuilding, or shower room. With a choice of power rating the electric instantaneous water heater can meet nearly every possible need.

Smaller 6-8 Kw units can supply a hand wash basin or a shower and the larger 8-12 kW units can supply both or provide a more powerful showering experience. We do usually recommend that you use a small store for kitchen sinks as this will provide higher flow rates. Our 12 kW units can supply approximately 4.5 litres a minute at 48 °C for a kitchen sink, depending on the temperature of the cold water supply if water flow is less important than an endless supply.

Our mini-instantaneous water heaters are perfect for your bathroom or putting under the sink. They can provide your hand basin with water at 35 to 40 °C for hand washing.

Energy Efficiency

When it comes to instant hot water, these are some of the most energy efficient products you can get on the market. They have no standby energy losses as they do not use any power until the water starts to flow. There is also no need to have a stored cylinder which saves more on electricity. When the water starts to flow (i.e., when you turn the tap on), the heater powers up and as the water flows through the unit, it is heated to the desired temperature. As soon as the water stops flowing, the water heater instantly powers down.

Installation & Safety

To be able to install instant hot water heaters, you will need access to the mains water and an electricity outlet. Whilst all our products come with installation instructions, we would recommend that you seek advice from a qualified trades person regarding installation of your product. All our products feature a safety cut-out function which prevents them from overheating and ensuring that your safety is priority. Due to the safety rating of our products, they are all ideal for both commercial and residential environments.

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Product reviews

4.9100% Positive (8 reviews)

Ratings based on data collected by third party reviewing platform.


Muhammad Mulakhill
3 September 2021 08:48

Stiebel Eltron DHB-E 18/21/24 - 203866 Set (Three Phase) Touch Instantaneous Water Heater 3i technology

This is the third one I installed. 24kW 3 phases. Wow.

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I asked for next day delivery, they promised, and lived up to it.

Thank you so much for taking the time to leave an excellent rating. We really appreciate your business.


Robert Burton
11 August 2021 08:42

Stiebel Eltron DHB-E 27 - 203865 Set (Three Phase) Touch Instantaneous Water Heater 3i Technology

As noted, easy to identify and order.

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After identifying the part required, a simple procedure to place the order and make the payment, arrived the next day ( Top Marks ).

Thank you for the 5 star review! We appreciate you taking the time to complete this.
It is lovely to hear you had a great experience with us.


Jeremy Clifford, Stockport
23 July 2021 12:06

Stiebel Eltron DCE-X 10/12 Premium - 238159 (Single Phase) Instantaneous Water Heater 4i Technology

Having had a bad experience with a different manufacturers product we are extremely happy with this produce as it is far superior

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They we knowledgeable, helpful & very reassuring as we hah had a bad experience with a previous water heater company

Thank you for the positive review. We are glad to hear our customer service team were able to guide you through the process.
It is great to hear you are happy with the new, superior water heater.

Thank you for choosing the Heater Shop.


Ian Norcup
25 April 2021 07:13

Stiebel Eltron DCE-X 10/12 Premium - 238159 (Single Phase) Instantaneous Water Heater 4i Technology

I am in awe of the capabilities of such a small unit but so far it as been amazing and fits my requirements to perfection,hope it stands the test of time.

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No problems so far but I have only had the unit up and running for a couple of days,after sales is very important bot hopefully won’t need it,delivered quickly and efficiently.

Thank you for your positive feedback. We appreciate your business with us.


Trusted Customer
23 March 2021 09:18

Stiebel Eltron DEM 6 Set Instantaneous Unvented Water Heater

Not connected it up yet - waiting for electrician to add 40 amp MBO to consumer unit

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Item delivered BEFORE expected date


Lee Ellingworth, Leicester
4 January 2021 09:08

Stiebel Eltron DEM 3 Set Instantaneous Unvented Water Heater

Best price you will find anywhere!

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Really good service, very polite and knowledgeable and extremely quick delivery!

Thank you very much for the really wonderful feedback.


Keith Wylam
16 December 2019 15:08

Stiebel Eltron DHC-E 12 Set - 236448 (Single Phase) Compact Instantaneous Water Heater

It was what I wanted and the price was very good

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Quick and efficient. Delivery arrived within 48 hours

Thank you for the fantastic feedback.


Trusted Customer
6 November 2018 22:04

Stiebel Eltron DEM 3 Set Instantaneous Unvented Water Heater

Efficient and helpful. Product delivered on time.

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Efficient and helpfulet.

Thank you for your really great 5 star review.

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