PRIMERASPORT first placed this question on Dec 30th - ‘Someone told me that over a 24 hour period, you will hardly use any more gas by leaving your central heating on low all night in the cold weather as opposed to switching it on every morning and having to heat the water from stone cold...is he talking **?’ However the thread descended into chaos without providing a definite answer. I searched the forum & found my original topic on this subject under the name (deliberately controversial) ‘Central heating timers are a waste of time’ on 7/11/03. All the replies were supportive, probably because they had already tried keeping their heat on all night without being deterred by reactionaries . These are all the postings I could find from members who had tested the setting, found it satisfactory & not a waste of energy. Of course many more users would not be forum members or have reported their experiences. susie 9/11/03. diyaster 9/11/03 Pugley 9/11/03 ADSL Nation 10/11/03 plumberandgas.com 10/11/03 dewaltdisney 30/6/04 graceland 2/1/09 Refurb Bob 10/1/09 Total of members including myself reporting satisfactory results & no increase in energy use; Nine Number of members having tested the setting with unsatisfactory results and/or energy wastage; Zero. I leave it to the questioner to judge whether all the satisfied users reporting to the Screwfix forum are fools or liars, as implied by a few detractors.