Carpenter said:Most oil fired boilers allow temperature to be adjusted from 60 deg up to 90 degrees, I'm sure the range is similar on the gas boiler. The temperature should be reduced during the summer when hot water only is required, increasing the temperature during the colder winter months. I would recommend setting the temp. at least to 65-67.5 degrees anyway as any lower could allow bacteria to grow in the immersion storage tank. During the winter months I would suggest 80- 85 degrees. You could also cut down on heat losses from the system by ensuring that all pipework connected to the hot water cylinder are lagged for at least 1m from their connection to the tank- this is a building regulation requirement which is routinely ignored. Fitting thermostatic radiator valves to your radiators (if not already fitted) could further improve the efficiency of the system.
Carpenter said:Reference to "Building Regulations TGD Part L, Section 3: Insualtion of Hot Water Storage Vessels, Pipes and ducts" says otherwise!
"The hot pipes connected to hot water storage vessels, including the vent pipe and the primary flow and return to the heat exchanger, where fitted should be insulated.....for at least one metre from their point of connection or up to the point where they are concealed"
Check out http://www.environ.ie (www.environ.ie) for full extract of the Technical Guidance document in PDF file.