The LP241 programmer is our entry-level programmer, with separate heating and hot water schedules. The LP241 includes a 24-hour program option that lets you tailor your daily 'on' and 'off' intervals to fit your lifestyle. It is possible to arrange up to three independent heating and hot water intervals. The advance boost button can be used to provide 1, 2, or 3 hours of heating and/or hot water in advance of your chosen time periods, saving you the time and effort of having to reprogram if you need a one-time burst of heating or hot water. The LP241 is suitable for folks who have a structured lifestyle but demand hot water and heating at various times throughout the day. If you have a more diverse lifestyle, aLP522 may be a better option. The same specifications as the LP241, but with a Service Interval. It's easy to use 24 Hour program Heating and hot water have their own timers. Automatic summer/winter time updates are pre-programmed into the clock. Saves data in memory There are three-time control periods that can be programmed. Switching options include on/once/timed/off. Backlit screen for easy reading To temporarily advance the heating, press the Boost button.