The Strom Touch Screen Single Phase Instantaneous Water Heater is a wall-mounted electric instantaneous (tankless) water heater available in 9kW, 11kW, and 13.5kW outputs — delivering an unlimited supply of hot water on demand at mains pressure, with no storage cylinder required. A compact 358 × 246 × 85mm body conceals a patented enclosed-loop multi-strand heating element that heats water as it flows through, feeding multiple outlets simultaneously. The large widescreen LED touch screen displays both output and target temperatures in real time and gives audible feedback on button presses — set the exact temperature you want and the heater maintains it automatically. Splash-proof matte IMD front cover, automatic fault detection with on-screen error codes, and an ErP energy efficiency rating of A across all variants. Suitable for domestic multipoint hot water, shower feeds, kitchen and bathroom top-up, loft conversions, and off-gas properties. Minimum inlet pressure just 0.2 bar. 5-year manufacturer's warranty when registered within 45 days of purchase.

⚠ Part P Qualified Electrician Required — All variants require a dedicated circuit from the consumer unit wired by a Part P registered electrician. Minimum cable and breaker sizes vary by model — 9kW: 6mm² / 45A MCB; 11kW: 10mm² / 50A MCB; 13.5kW: 10mm² / 63A MCB. Ensure your consumer unit has a spare way of sufficient rating before ordering. Plumbing connections are standard ½" BSP male and can be made by a competent person.

ℹ Choosing Between 9kW, 11kW, and 13.5kW
The right output depends on your incoming cold water temperature and your desired hot water flow rate. As a practical guide for UK mains temperatures (10–15°C inlet in winter): the 9kW delivers a comfortable 37°C at approximately 3.5 L/min — sufficient for a single shower or basin. The 11kW raises this to approximately 4–5 L/min at the same temperature — suitable for a standard shower head or one basin plus one outlet. The 13.5kW provides approximately 5–6 L/min at 37°C — the best choice for higher-flow showers, multiple simultaneous outlets, or properties where the incoming cold water is particularly cold (e.g., rural mains or winter loft installations). Higher output always gives more flexibility; if in doubt, specify the next size up.

9 / 11 / 13.5 kW

Three variants

Unlimited

Continuous hot water

0.2 bar

Min inlet pressure

ErP A

Energy rated

5 years

Warranty (registered)

Features & Benefits

✔ Patented Enclosed Loop Multi-Strand Heating Element

The Strom instantaneous heater uses a patented enclosed loop heating system with multiple independent heating strands inside a single element unit. Unlike competitors that use a single strand — concentrating thermal stress at one point — Strom's multiple strands share the load, reducing element fatigue. Heat is transferred across the entire surface area rather than through a localised hot spot, which eliminates the differential thermal stress that accelerates limescale deposition. The element is a single replaceable unit (not a submerged element inside a small tank), making servicing straightforward. Water is kept separate from the heating strands throughout, further reducing corrosion.

✔ Multi-Layer Chamber — Reduced Limescale

The multi-layer heating chamber is specifically designed to reduce limescale accumulation — the most common cause of performance degradation and element failure in instantaneous water heaters. Because hotspots are eliminated by the distributed heating surface, calcium carbonate (limescale) is less likely to precipitate and adhere at any single point. Over time, this means the heater maintains closer-to-original output temperatures and flow rates compared to single-strand element designs, which can lose significant efficiency as scale builds on the element surface. Particularly beneficial in hard water areas of England and Wales.

✔ Touch Screen LED Display — Set Temperature & Hold

The large widescreen LED touch screen simultaneously displays the current output temperature (what is coming out of the tap) and the target temperature (what you have set). Touch the up/down buttons to set the desired output temperature and the heater's modulating element automatically adjusts power to maintain it — no manual flow adjustment needed to chase a comfortable temperature. Audible button feedback confirms every press. The display also shows automatic fault codes if a problem is detected — rather than the heater simply failing silently, the screen identifies the fault type, making diagnosis and service faster.

✔ Splash-Proof IMD Front Cover — Indoor Zones

The unique matte IMD (In-Mould Decoration) splash-proof front cover provides protection against water splashes from taps, showers, and accidental spills — making the unit safe for installation in bathrooms (in the appropriate IP zone), en-suites, kitchens, and utility rooms. IMD construction integrates the surface finish into the moulding itself, unlike printed overlays that can peel or fade over time. The matte ABS body is 358 × 246 × 85mm — shallower than a typical storage water heater — and can be surface-mounted to a wall or partially recessed into a stud partition.

✔ No Storage — No Heat Loss — No Legionella Risk from Store

As a true instantaneous heater there is no stored water — cold water enters the unit only when a tap is opened, is heated as it passes through the element, and flows immediately to the outlet. This means zero standing heat losses (the unit draws no energy when no hot water is being used) and no stored water volume that could harbour Legionella. For properties where a storage cylinder poses a Legionella management burden — care homes, commercial premises, holiday lets — an instantaneous heater eliminates the stored water risk at source, though installer responsibility for system risk assessment remains.

✔ 0.2 Bar Minimum Pressure — Wide Compatibility

A minimum inlet pressure of just 0.2 bar means the Strom instantaneous heater works reliably even with poor mains pressure — covering rural properties, high-floor flats, loft conversions, and gravity-fed systems where many competitors' units would fail to activate. Maximum working pressure is 6 bar — within the range of all standard UK mains supplies. No pump or pressure booster is required in most domestic installations. The ½" BSP male water connections match standard UK plumbing and can be connected directly to ½" compression or push-fit fittings.

Technical Specifications — All Variants

Specification	9kW (SEIH9KTS2)	11kW (SEIH11KTS2)	13.5kW (SEIH14KTS2)
Heat Output	9.0 kW	11.0 kW	13.5 kW
Voltage	230VAC	230VAC	230VAC
Rated Current	40A	48A	62A
Min. Cable Size	6mm²	10mm²	10mm²
Min. MCB / Breaker	45A	50A	63A
Max. Recommended Flow Rate	5 L/min	6 L/min	7 L/min
Min. Inlet Pressure	0.2 bar	0.2 bar	0.2 bar
Max. Working Pressure	6 bar	6 bar	6 bar
Temperature Cut-Out	67°C	67°C	67°C
Water Connections	½" BSP male	½" BSP male	½" BSP male
Control Method	Touch screen LED	Touch screen LED	Touch screen LED
Body Material	Matte ABS	Matte ABS	Matte ABS
Dimensions (H × W × D)	358 × 246 × 85 mm	358 × 246 × 85 mm	358 × 246 × 85 mm
ErP Rating	A	A	A

Frequently Asked Questions

What temperature will the hot water come out at?

The output temperature of an instantaneous heater depends on three variables: the input power (kW), the incoming cold water temperature, and the flow rate at the tap. The heater adds a fixed amount of thermal energy per litre flowing through it — the faster the flow, the smaller the temperature rise per litre. As a practical example: at a 12°C cold inlet and 40A rated current (9kW), running at 3 L/min gives approximately a 42°C rise, delivering ~54°C at the heater outlet. Reduce flow to 2 L/min and the rise increases; open a second tap and total flow rises, reducing the rise per litre. You adjust temperature by adjusting flow at the tap — the touch screen set point tells the heater the ceiling, not a guaranteed delivery temperature regardless of flow. The Strom's modulating element helps compensate for flow variation, but physics limits what any instantaneous heater can do at very high flow rates.

Can I use this as the sole source of hot water in a property?

Yes — the Strom Touch Screen is designed for multipoint whole-property hot water supply, not just a single point-of-use. A single 13.5kW unit can typically serve a 1–2 bathroom property with sequential (not fully simultaneous) demand. For larger properties or where two outlets run simultaneously at full flow (e.g., shower and bath filling together), two units on separate circuits may be needed — or a larger output is required. For properties currently on gas with a combi boiler, the electric instantaneous heater is the most direct equivalent: same on-demand delivery concept, same multipoint capability, no storage. The key difference is that electrical cost per kWh is higher than gas, so pairing with solar PV (using a diverter) or an off-peak tariff is recommended where possible.

Does my consumer unit need upgrading?

It depends on the current state of your consumer unit. The 13.5kW model requires a 63A MCB on a dedicated circuit — most modern consumer units have ways available, but the busbars and main incomer must be rated for the additional load. If your property has an older 60A or 80A main fuse, adding a 63A circuit may exceed the total available supply — an electrician should assess this before purchase. The 9kW (45A MCB) and 11kW (50A MCB) are more likely to fit within existing capacity. A Part P registered electrician should always check the consumer unit rating, available ways, and total load before installation. In some cases a 100A supply upgrade from the DNO may be needed — this is typically free for residential properties below the threshold but takes several weeks to arrange.

Can it be used with solar PV?

Yes — the Strom instantaneous water heater is fully compatible with solar PV diversion. A solar diverter (such as the myenergi Eddi or an iBoost) monitors the property's generation and import/export balance, and diverts surplus solar electricity to the water heater's supply when more is being generated than consumed. Because the instantaneous heater only draws power when hot water is being run, it is best used in combination with a solar diverter that can modulate power to the heater — match the heater to the diverter's compatible load range. This is one of the most effective ways to use surplus solar generation in properties without a hot water cylinder — displacing grid electricity consumption with effectively free hot water from daytime generation.

What does the fault detection display?

The touch screen's automatic fault detection system monitors the heater's internal sensors and displays an on-screen error code when a fault condition is detected — rather than the unit simply cutting out with no indication. Common fault codes cover over-temperature (water or element above the 67°C safety cut-out), flow sensor errors (no water detected when power is applied), and element faults. The display of a specific code allows a service engineer to diagnose the issue before opening the unit, speeding up repair time. Error codes and their meanings are listed in the Strom installation and user manual, available from stromltd.com.

What is the warranty and how do I register?

The Strom Touch Screen instantaneous water heater carries a 5-year manufacturer's warranty when registered at stromltd.com within 45 days of purchase. Registration requires the product serial number and proof of purchase date. If the product is not registered within 45 days, the warranty defaults to 1 year. The warranty covers manufacturing defects in materials and workmanship. Installation must have been carried out correctly by a competent electrician and plumber, and the unit must have been used within the specified pressure and electrical parameters. Strom can be contacted at 0333 344 24 74 or sales@stromltd.com for warranty and technical support.

Instant Water Heaters