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1.3 Combi General Requirements
The boiler will have a DHW priority when both domestic hot water (DHW) and central
heating (CH) are selected. So if the flow switch is closed or the heat store has not
been satisfied the entire output of the boiler is directed to DHW before the boiler will
switch over to CH. When fully cold it can take up to 20 minutes for the heat store to
be satisfied.
After a draw-off of 20L at 24L/min, with an average temperature rise of 32°C, the
thermal store has a recovery time of approximately 7 mins.
Note
: If HW has not been selected no hot water can be produced even if the heat
store is up to temperature.
1.3.1 Pump Over-Run
Where there is a build up of excess heat in the boiler primary heat exchanger and
the central heating has not been selected then the pump over-run thermostat
will operate. The excess heat will then be pumped into the heat store. Once the
temperature has fallen in the boiler and the pump over-run stat is satisfied or the
central heating pump starts to operate, then the hot water pump will stop.
1.4 Baffle Positioning
Before firing make sure the baffles have not been dislodged in transit. To achieve
maximum efficiency push the primary heat exchanger baffles in the direction of
the arrows as shown. The secondary heat exchanger spring baffles must be fully
inserted into the heat exchanger tubes (narrow end first).
