Frost Protection; Circulating Pump; Anticycling 'Economiser' Control; Automatic Pump Spin Control (Aps) - Vaillant ecoTEC plus 612 Instructions For Installation And Servicing

4.17 Frost protection

The boiler has an integral frost thermostat which is
designed for protection of the boiler. To protect remote
or exposed parts of the heating system or property
additional frost protection measures must be taken such
as the installation of an external frost thermostat. This
frost thermostat should be connected across the boiler
terminals 3 and 4, in parallel with any external heating
controls.
Note
External frost protection cannot be used when
plug in timers are utilised.

4.18 Circulating pump

The boiler incorporates a built in circulating pump that
is fully prewired (no additional wiring is necessary). The
pump incorporates an automatic overrun period after
the boiler switches off.

4.19 Anticycling 'economiser' control

The boiler incorporates a built in anticycling control to
ensure that energy wasteful short cycling of the boiler
cannot occur. This control prevents the boiler from re-
igniting for a preset period after central heating opera-
tion (the hot water operation is unaffected by this con-
trol and hot water can be drawn at any time).
Note
To temporarily override the anticycling control
turn the main boiler on/off switch to the off
position "0" and then back to the on position
"I" after a few seconds.

4.20 Automatic pump spin control (APS)

The boiler incorporates a built in control which will spin
the built in circulating pump and operate the diverter
valve (ecoTEC combination boilers only) once in a 23
hour period. This control helps to prevent seizure when
the boiler is not operated for a period of time. This con-
trol is not active when the power supply to the appli-
ance is turned off.
Instructions for installation and servicing ecoTEC / 839592_09
Boiler installation sequence 4
29