Heating Pump; Anti-Cyclic "Economiser" Control System; Automatic Pump Spin Control; Commissioning, Part I 5 - Vaillant ecoTEC plus 937 Instructions And Maintenance Instructions

Note
h
External frost protection devices cannot be
used if plug-in timers are used.
4.23

Heating pump

The combi boiler is fitted with a heating pump which is
fully wired (additional cabling is not necessary). The
pump has automatic overrun time after the combi boiler
has switched off.
4.24

Anti-cyclic "Economiser" control system

The combi boiler is fitted with an anti-cyclic controller
which ensures that energy wasting short term running
of the combi boiler cannot occur. The controller pre-
vents the combi boiler from switching on again within a
preset time period after the last switch-off of the cen-
tral heating. (Hot water preparation is not affected by
this function. Hot water can be drawn off at any time.)
Note
h
For temporary cancellation of this switch-on
protection system, turn the main switch ON/
OFF of the combi boiler to position "0" and
then a few seconds later switch to position "l".
4.25

Automatic pump spin control

The combi boiler is fitted with an internal controller
which causes the fitted heating pump to switch on once
in a 23 hour period and also operates the diverter valve.
This controller prevents the jamming up of these com-
ponents if the combi boiler is inactive for long periods.
This controller is inactive if the power supply to the unit
is switched off
Installation and maintenance instructions ecoTEC plus 0020031552_03
Sequence of operations during installation 4
5 Commissioning, Part I
5.1

Preparatory checks of the electrical system

• Check the electrical installation for short circuits,
proper earthing and earth resistance and for correct
polarity.
5.2

Gas supply

The entire gas installation including the gas meter must
be inspected, checked for leaks and purged in accord-
ance with BS 6891. In the Irish Republic (IE) in accord-
ance with the current version of IS 813.
• Purge the gas supply by opening the gas isolator valve
under the unit.
d Danger!
Danger of explosions!
Provide adequate ventilation whilst doing the
work.
Extinguish all open flames and do not smoke
during purging.
• After purging re-tighten the gas isolator valve and
check for leaks. (The combi boiler itself does not need
to be purged.) This takes place through the automatic
burner ignition monitoring system.)
5.3

Cold water supply

• Open all the domestic hot water taps supplied by the
appliance.
• Open the mains water isolating valve supplying the
appliance.
• Open the cold water isolating valve under the appli-
ance. The water then flows through the combi boiler
and the shift load storage tank to the hot water taps.
• Close all the hot water taps one after the other start-
ing with the lowest one until the hot water pipework is
vented.
• Check all hot and cold water pipes for leaks.
5.4

Filling the heating system

h Note
Use the following test programmes for filling
and venting the heating system:
Filling the heating system
• Use the test programme P6 for filling the heating sys-
tem:
The diverter valve moves to the central position, the
heating pump is not running and the unit does not go
into heating mode.
• Use the test programme as described in Section 8.2.
Vent the heating system
• Use the test programme P.0 to vent the combi boiler,
the heating system and the hot water circuit:

Commissioning, Part I 5

31