BS EN 26:2015

What is BS EN 26 - Gas-fired instantaneous water heaters for domestic use about?

BS EN 26 is a European Standard that discusses gas-fired instantaneous water heaters for the production of domestic hot water. The main aim of BS EN 26 is to provide manufacturers with best industry guidance to ensure gas-fired instantaneous water heaters are safe and reliable to use.

BS EN 26 defines the specifications and test methods concerning the construction, safety, rational use of energy and fitness for purpose, and also the classification and marking of gas-fired instantaneous water heaters for sanitary uses, hereafter called “water heaters”.

BS EN 26 applies to water heaters:

• Of types AAS, B11, B11BS, B12, B12BS, B13, B13BS, B14, B22, B23, B32, B33, B44, B52, B53, C11, C12, C13, C21, C22, C23, C32, C33, C42, C43, C52, C53, C62, C63, C72, C73, C82and C83 according to CEN/TR 1749
• Fitted with atmospheric burners
• Equipped with atmospheric burners assisted by a fan for the supply of combustion air or evacuation of combustion products or fully premix burners
• Using one or more combustible gases corresponding to the three gas families and at the pressures stated in accordance to EN 437
• Of nominal heat input not exceeding 70 kW
• With an ignition burner or with direct ignition of the main burner

In BS EN 26, the heat inputs are expressed in relation to the net calorific value (Hi).

BS EN 26 does not contain all the requirements necessary for:

• Boiling water appliances
• Appliances intended to be connected to a mechanical means of evacuating the combustion products
• Appliances which fulfil a dual role of space heating and heating water for sanitary use
• Appliances making use of the heat of condensation of the water contained in the combustion products
• Water heaters of types B21, B31, B41, B42, B43 and B51

BS EN 26 only covers water heaters where the fan, if any, is an integral part of the appliance.

Note: BS EN 26 does not apply to appliances not intended to be connected to a flue when they are not fitted with an atmosphere sensing device.

Who is BS EN 26 - Gas-fired instantaneous water heaters for domestic use for?

BS EN 26 on gas-fired instantaneous water heaters is relevant to:

• Gas-fired water heater manufacturers
• Gas-fired water heater parts and component manufacturers and suppliers
• Anyone involved in design, construction, maintenance, installation and commissioning of gas-fired water heaters
• Quality control and testing authorities
• Building management authorities
• Local bodies

Why should you use BS EN 26 - Gas-fired instantaneous water heaters for domestic use?

A gas water heater is a gas-fired hot water generator. Such a water heater has a burner that generally heats water by means of natural gas. While they make for a good alternative to electric water heaters for domestic purposes, there are several potential failure risks that need to be mitigated to ensure the gas water heater is efficient and safe to use.

In this regard, BS EN 26 covers best industry guidance on the constructional and operational requirements, rational use of energy, and test methods to ensure gas-fired water heaters are fit for purpose.

Requirements for elastomeric seals and elastomeric sealants in the combustion product, evacuation ducts, terminals and fitting pieces is also covered in BS EN 26.

Testing in compliance with BS EN 26 helps demonstrates whether your gas-fired instantaneous water heaters can provide long-term resistance to thermal loads and condensate exposure.

As a result, adopting BS EN 26-compliant test methods and requirements can ensures that failures such as improper water pressure, overheating, leakages and corrosion are avoided.