Do I have to install my boiler beside an outside wall?

Q. In the breakfast room/kitchen in my house the gas boiler is situated in a press in the room away from the outside wall. For the past year the heating is operating satisfactorily but periodically the water is not heating. The plumber has advised me that I need to replace the boiler which is 15 years in place. He further stated that I need to relocate it to inside an outside wall. As this work would necessitate the laying of pipes under the floor and the removal of floor boards and a kitchen press to accommodate it, I am asking if there is any type of boiler available that could be located inside the house away from the outside wall.

A. From March 31st, 2008, all gas- and oil-fired boilers installed as replacements in existing dwellings must meet a minimum seasonal efficiency of 86 per cent, where practical. This requirement was introduced as part of the revision of the Building Regulations, Part L, Conservation of Fuel & Energy, adopted in December 2007.

Currently, the only boilers achieving this performance level are condensing boilers. However, the Department of Environment in consultation with the Sustainable Energy Authority of Ireland, produced a guide to installing condensing boilers in existing dwellings and set out a procedure to be followed to assess specific situations where the provision of condensing boilers is not practical.

The condensing boiler installation assessment procedure is to be used in cases where it is expected that the installation of a condensing boiler, as a replacement boiler in an existing dwelling, may not be “practicable”. Practicable is to be taken to mean “capable of accomplishment after taking into consideration the existing state of technology and economic feasibility for the facility involved”.

I note from the photograph which you have included with your question that your boiler is currently located centrally within your house. This is not untypical in older properties where an air-based system was originally installed centrally so that air could be circulated to the ground-floor rooms and upper-floor bedrooms without the use of significant ductwork.

The problem with regard to the placement of a condensing boiler centrally in the house is that condensing boilers generate condensation and a discharge pipe is therefore necessary. Typically, this necessitates the placement of the boiler on, or close to, an external wall. Restrictions with regard to flue lengths and locations in terms of proximity to windows, doors and vents, also need to be considered if changing the boiler location.

If you are resolved to maintaining the existing boiler location, you should investigate if there are waste pipes serving toilets or bathrooms nearby which you could easily access to make a connection for the condensation run-off.

Otherwise, you may have to resort to installing an efficient non-condensing boiler. Your plumber will need to complete the assessment to demonstrate why the requirement of the building regulations has not been met.

There may also be potential for relocating the boiler elsewhere within your house, which does not necessitate the removal of floor finishes and kitchen presses etc. Most boilers are room sealed and can be placed anywhere within your house on the proviso that the flue meets the requirements of building regulations and condensate run-off can be accommodated.

It would be worthwhile having your property inspected by a local chartered building surveyor to help consider all options which may be available to you.

Noel Larkin is a chartered building surveyor and member of the Society of Chartered Surveyors Ireland, scsi.ie