c) allows power to PCB to produce and provide modified voltage to hold valve in mid position against the strength of the return spring. Using the RESET procedure may rectify the fault. If the problem persists the programmer will need replacing. The programmer is fitted with a non-rechargeable, long life battery, which will maintain the programmed time settings for a minimum of ten months with the supply disconnected.

Should you encounter any problems, please refer to the Question and Answer section SPECIAL FEATURES This indicates that you have reached an existing set time period, you will be unable to set a new ON/OFF time unless there is an alteration to the existing timed period The Secure Meters Horstmann CHANNELPLUS H27XL is a white 2 channel 7 day electronic digital programmer with independent timing of heating and hot water.. User friendly, it is designed for domestic use, providing advanced, easily programmed features.The installer will have set the programmer to suit the installed system. If this is a Fully pumped system this will allow independent control of the Central heating and Hot water, however on a Gravity system the Central heating and Hot water are linked so that it is not possible to use the Central heating independently. This will allow only one common time setting for both Hot Water and Central Heating. BATTERY The simple instructions below are designed to help with the programming of the unit. All the following instructions require the front flap to be lowered. Please replace the flap when normal operation is required. SETTING DAY AND TIME OF DAY Turn the battery on. The switch on the rear of the unit must be in either the Fully Pumped or Gravity position. Your programmer will prevent you from accidentally overlapping ON and OFF times. Example: If the 2nd ON time is set at 12:00pm and then you try and set the 1st OFF at 12:30 pm the OFF setting will 'bounce' by a 10 minute period until the 2nd ON time has been adjusted. FULLY PUMPED OR GRAVITY SYSTEM So using the lever will not take the valve the full distance and not far enough to trigger micro switch to cut (c) and make (d)

If a Heating or Hot water period is not required it can be cancelled by setting the ON and OFF settings to the same time. Example ON 10:00am OFF 10:00am

I also don't really understand how each of the two-way valves operate - whether the timer "job shares" between the two zones and whether two NEST thermostats can replace that functionality. Or if each thermostat demands heat and the timer is on for each zone, both valves just open and they get served with hot water equally. The default factory settings are shown, however if you wish to change these proceed as instructed below. By pulling outward and generally downward I can clearly see the single wall box because I am dragging that towards me too. It is not separating from the main unit or the stand-off. I am wondering if the stand-off comes away from the main unit. I can pull the main unit away from the stand-off enough to get a screwdriver into the gap but it's not coming away consistently - only where I exert pressure so much that the plastic deforms. For instance, I *hope* the cabling to each thermostat allows for me to install the NEST power supply (supplies?) in the hot tank cupboard (where the timer currently lives) and power each thermostat (remotely) that way.

Whilst the HOLIDAY FUNCTION is in operation the system will remain OFF, the display will show the number of nights remaining. The HOLIDAY setting is an instant function and cannot be set in advance. The HOLIDAY FUNCTION can be cancelled at any time by pressing any of the SELECT buttons. Normal programme functions will resume at the first ON period after the pre-set number of nights has expired. INFORMATION AND ADVICE Programming ON/OFF times What I really want to do is to install a NEST in place of the two thermostats, and a single timer for the water but I don't yet understand what wiring my system employs and how I might convert that for NEST. Of course if HW is selected and not satisfied, the boiler/pump will run, because the power is supplied through the cylinder stat and not the valves orange wire.

During power interruptions the display will be blank, after 3 days the current time of day will be lost. If the programmer is not to be used for a long period of time, the switch on the rear of the unit should be returned to the BATTERY OFF position. These are both to prolong the battery life. SERVICE AND REPAIR