One of the most asked questions, answered!
The frequent enquiry about whether an instantaneous water heater can fill a bath tops our list of common questions related to water heating.
If you're seeking a swift and efficient way to heat water for your bath, you may be curious about the capabilities of an electrical instantaneous heater. Also known as tankless or inline water heaters, these devices heat water on demand as it passes through, eliminating the need for a storage tank. This results in energy efficiency as it only utilises electricity when hot water is needed, ensuring a continuous supply at the point of use.
Despite the advantages, such as compactness and efficiency, this type of water heater has drawbacks, including the high kW requirement for adequate heat and the challenge of delivering fast-flowing hot water for filling large vessels like baths. The most powerful domestic instantaneous water heater (single-phase electricity) typically reaches around 12kW (50A), providing approximately 5L per minute at a bathing temperature of 38-40 degrees Celsius. For an average-sized bath containing an average-sized adult, requiring around 100L of water at this temperature, the math indicates it would take approximately 20 minutes to fill using the most powerful heater. However, during this time, the already heated water may cool down, depending on ambient temperature. Consequently, we would suggest that an instantaneous water heater is less than ideal for bath filling.
This analysis centers on the Zip DEX12 water heater. While Zip claims its suitability for filling a bath, we disagree based on the outlined reasons and do not recommend it for that purpose, despite its effectiveness in other applications.
For those in search of a water heater better suited for bath filling, consider exploring the Hyco Powerflow 80L or 100L, or the Heatrae Sadia Hotflo 80L. These are sleek wall-hung water heaters, offering alternatives to bulkier cylinders.
For further enquiries or assistance in choosing the right heater, whether instantaneous or otherwise, feel free to contact our knowledgeable water heating experts at 01934 311800.