Ms Sarah Neary:

I thank the committee for inviting the Department of the Environment, Community and Local Government to assist in its consideration of issues raised in the petition. I am the senior technical adviser in the architecture and building standards section of the Department. I am accompanied by my colleagues Eamonn Smyth, engineering adviser, and Martin Vaughan, assistant principal.

The subject before the committee is technical in nature and the Department is happy to outline its understanding of the relevant product standards, technical guidelines and regulatory controls at home and abroad that inform consideration of this matter. I note that the National Standards Authority of Ireland, from which we have just heard, has also accepted the committee’s invitation, and I welcome its participation in the discussion.

It is important to note that with effect from 1 January 2014, Irish Water assumed statutory responsibility for public water services under the Water Service Acts. Irish Water is now the designated national authority with responsibility for water services, and the quality and integrity of the water supply in general comes within the remit of Irish Water. As such, any questions from committee members on this aspect of the matter must be directed to Irish Water.

It might be helpful to summarise the existing and proposed regulatory arrangements relevant to the matters raised in this petition. The petitioner’s issue relates to the installation of a sealed primary heating circuit as part of an indirect vented hot water system. His concerns focus on the method of filling the sealed circuit with water and the potential for backflow contamination. The sealed primary heating circuit is the pipework that goes from the boiler to a coil in the hot water cylinder. While sealed circuits have existed for some time in the industry and are used in many jurisdictions across Europe, they are relatively new in Ireland. Traditionally, hot water systems in Ireland had vented primary heating circuits, which effectively meant there was a dedicated feed and expansion cistern for the boiler in the attic, in addition to the main cold water storage tank. For a sealed primary heating circuit, the feed and expansion cistern for the boiler are redundant. The sealed system is fitted with an expansion vessel to accommodate the increased volumes. In terms of supplying a feed to fill this circuit, a temporary connection is typically made to the mains water supply.

British Standards have dealt with these systems for some time. The current British standard is BS 8558, "Guide to the design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages." That is complementary guidance to the European suite, EN 806. This standard outlines the proper procedures for sealed circuits. It sets out how the connection to the mains water supply may be made by providing a servicing valve, a temporary connecting pipe and an appropriate backflow prevention device.

This arrangement presents some risk to the mains supply, and the petitioner rightly refers to this. Normally, the pressure in a primary heating circuit is less than that of the mains supply pipe.

However, if a fault occurs in a pressure relief valve in the system for example, the pressure in the circuit could rise above the pressure in the mains. If the servicing valve is left in the open position and the backflow prevention device fails, there is potential for backflow of the fluid in the heating circuit into the mains supply. This has the potential to cause contamination of the mains supply. For the avoidance of such backflow and contamination, the temporary connecting pipe must be completely disconnected from the outlet of the backflow device and the connection with the primary circuit after the completion of filling or periodic replenishing. BS 8558 also provides guidance on the prevention of stagnation associated with this temporary connection.

The petitioner has also raised the issue of the type of backflow devices suitable for these installations. The standard for backflow prevention devices is IS EN 1717. This standard deals with the means to be used to prevent the pollution of potable water inside premises and the general requirements of protection devices to avoid pollution by backflow.

The national annex to EN 1717 recommends carrying out a risk assessment if using backflow prevention valves to ensure fitness for purpose. It also advises that permission should be sought from the water services authority. Any backflow protection device should be fit for purpose, manufactured in accordance with the relevant product standards and installed by an experienced plumber or technician. The Registered Gas Installers of Ireland, RGII, includes the above guidance regarding the temporary connection to sealed heating circuits in its installation guides for gas heating systems. The oil fired heating systems associations, such as OFTEC, provide comparable guidance, and boiler manufacturers highlight this issue and provide explicit installation rules in their manuals.

The relevant legislation dealing with this aspect of water supply is the Water Services Act 2007. Section 54 provides that the owner of a premises shall ensure the internal distribution system of a premises is sufficient to ensure, and maintained in such condition as to ensure, water intended for human consumption meets prescribed quality requirements at the tap or taps used for such purposes. Irish Water has powers to issue notices to direct the owner of a premises to undertake remedial action where there is an issue with the quality of the water.

The National Standards Authority of Ireland, NSAI, has been developing an Irish code of practice for building services - domestic plumbing and heating. As Mr. Buckley explained, this has been put out for public consultation and is being reviewed. The NSAI committees will review and finalise the proposed code of practice for heating systems, hot water systems, cold water systems and, importantly, their interlinkages in the context of the suite of European standards known as EN 806. This will provide Ireland for the first time with a national standard for plumbing and heating. The Department is very supportive of this work by NSAI. The outcome of the work on the code of practice will inform the Department’s consideration of any further policy or regulatory proposals that may be necessary in this area.

That completes my overview of the existing and proposed regulatory arrangements relevant to the committee’s consideration of this petition. My colleagues and I look forward to participating further in the discussion or answering any questions the committee may have.