Product specifications

11.8 Pump head.
Isolate the electrical supply to the boiler.
Disconnect the electrical connections from the
pump terminal block (Fig 46).
Release the two bolts securing the pump head using
a 5mm-hexagon key, and remove the pump head
from the pump body.
Fit replacement pump head in reverse order. The
pump must be vented via its vent plug on refilling
of the boiler (venting shown in Fig 46) .
Figure 46
11.9a. Three way valve.
Isolate the electrical supply to the boiler. Unplug
the three-way valve's electrical connections from
the boiler control unit (Fig 44).
Disconnect the three compression pipe connections
o the valve and remove valve (Fig 47). t
Fit replacement three way valve in reverse order.
11.9b. Three way valve (head only).
Isolate the electrical supply to the boiler. Unplug
the three-way valve's electrical connections from
he boiler control unit (Fig 44).t
Press button on left side of the valve head and lift
off (Fig 47).
Fit replacement valve head in reverse order.
Figure 47
11.10 Central heating water temperature sensor.
Isolate the electrical supply to the boiler.
Disconnect the central heating water temp. sensor
electrical connections and unscrew the sensor from
its fitting using a 15mm spanner (Fig 48).
Fit the replacement sensor in reverse order.
(Beware of over-tightening the sensor! 1/4 turn
more than hand tight is normally sufficient).
Figure 48
Sensor
11.11 Temperature & pressure relief valve.
Drain the domestic hot water system (refer to
ection 9.3)s
Release the valve's outlet 22mm compression
fitting to the discharge pipe and remove the ½
fitting from the valve (Fig 49).
Unscrew the temperature & pressure relief valve
and remove.
Fit replacement valve in reverse order using a
sealant suitable for potable water.
ATMOS MULTI Mk 2 version 2008
Page 46