Rinnai announced on 27 January 2025 that it is introducing an updated E-Series range for UK customers, starting with the 17CE Condensing External Water Heater. The company said the upgrade is intended to give UK customers access to the latest developments in hot water heating technology1.
The 17CE weighs 18kg and is described as compact, requiring less space than alternative systems. Its temperature range is given as 37 to 65 degrees Celsius, with hot water delivery capacity of twenty litres per minute and gross efficiency measured at 93%. Rinnai also lists direct electronic ignition and frost protection among the additions1.
The same announcement gives a second, lower delivery figure for the unit: seventeen litres per minute. It does not explain the difference between the two figures1.
On fuel compatibility, Rinnai states that the 17CE condensing water heater is Bio-LPG ready, and that the natural gas continuous flow water heater is I2HY20 ready for hydrogen blends of 20%1.
"Rinnai is introducing the updated Rinnai E-Series early in 2025 with the 17CE Condensing External Water Heater."
Rinnai says microprocessors allow the customer to pre-set water temperature, delivered to within plus or minus one degree of the set point, which it says helps prevent legionella proliferation and delivery temperature inaccuracies that can cause discomfort or scalding. The company states that continuous flow systems consume no energy when not in use, so the customer pays no costs when the system is not operational1.
Rinnai names glamping sites, leisure facilities, festival ablutions and small commercial outlets among the intended applications for the 17CE, alongside situations requiring cost effective and durable condensing water heaters1. The announcement does not state a price, a launch date beyond "early in 2025", or whether the unit is intended for individual homes. Those details have not been reported1.
Why it matters for households
The 17CE is a continuous flow water heater, which heats water on demand rather than storing it in a cylinder. For a household, the practical difference is that no energy is used to keep a tank of hot water standing by, which Rinnai says means no cost when the system is not running1. That matters where a home's hot water demand is intermittent, since standing losses from a stored cylinder are paid for whether or not hot water is drawn.
The stated temperature control of plus or minus one degree is relevant to scald risk and to legionella management, both of which bear on how independently a household can run its own hot water supply1. The fuel options named, Bio-LPG and a natural gas blend containing 20% hydrogen, indicate the unit is designed to run on gases other than standard natural gas, though the announcement does not say which of these are available to domestic properties or on what terms1.
The listed applications are commercial and leisure settings rather than homes, so the relevance to a typical household is indirect. The wider boilers and heating picture, including how continuous flow units compare with stored hot water systems, is not covered in this announcement1.
What happens next
Rinnai says the updated E-Series will arrive early in 2025, with the 17CE as the first model named. No further dates, prices or product details have been reported1.
Sources1 cited
- Rinnai To Introduce New E-Series :: Rinnai UK, rinnai-uk.co.uk