Optimisers respond to changing conditions to ensure the desired room temperature is reached at the right moment, whilst conserving fuel by avoiding bringing your house up to temperature too early. Example: Most households requiring a comfort temperature of 21°c at 7.00 am would typically set the central heating programmer for 6.00 am. On particularly cold days, the house may not reach the optimal temperature by 7.00 am and on a milder day, it may do so too early, which means some energy could have been saved. You can simply set an 'Optimising' Room Thermostat to deliver your comfort temperature at your desired time. The optimiser will calculate the perfect time to switch the boiler on, ensuring optimum comfort and the best use of energy each day.