Instant Water Heaters

The Blue Sky instant heaters are all rated 3500W, and what separates them is the panel on the front. The SL-X9-35 is touch controlled, the SL-X5-35A carries an LED display and the SL-X5-35B a digital readout. The SL-X5-35D keeps things plain, and the SL-X7-35 comes in a slim case for a narrow stretch of shower wall.

How to choose

An instant heater warms water as it flows past the element, so there is no tank to wait on and nothing standing hot between showers. The trade is that the temperature rise depends on flow: open the tap wide and the water comes through cooler, which is why a unit like this serves one outlet at a time. Fitting counts for more than the model. A 3500W element on a 220-240V supply wants its own circuit, a correctly rated breaker and a sound earth, so have an electrician read the board before anything goes on the wall.

• 3500W instant heaters, with no tank and no reheat cycle
• SL-X9-35 touch control, SL-X5-35A LED display, SL-X5-35B digital
• SL-X7-35 in a slim case where wall space is tight
• Have the circuit, the breaker and the earth checked before fitting

Related: Blue Sky Water Heaters · Blue Sky · Cooling & Climate