The ST699 is an electronic central heating time control
programmer that can be used on gravity primary, or fully pumped
systems having separate heating and hot water temperature
control.
The programming sequence for the ST699 is straightforward,
using the top slider switch and [+] and [?] buttons.

ST699 can be either surface or flush
switch box mounted, for both of which
fixing screws are supplied. The wiring
sub-base has holes to suit single
switch boxes and breakouts for
surface and channelled wiring.
When wiring is completed the
removeable plug-in module is clipped
into the sub-base. It can be removed
if required by depressing the locking
catch with a screwdriver.
If the ST699 is used to provide time
control for a gravity hot water/pumped
heating system without separate
temperature control, it is not possible
to select Heating only without Hot
Water. For these installations a
HEATING and HOT WATER sticker is
supplied which should be placed over
the existing HEATING caption.