Supplied By www.heating spares.co Tel. 0161 620 6677
16
Installation Instructions - Page 16
OVERHEAT THERMOSTAT POSITIONING
Fig. 21A FULLY PUMPED POSITION
Fig. 21B GRAVITY DHW POSITION
If the boiler is fitted with a right hand flue, remove flue
elbow as described in Section 1 preparing the Boiler for
Servicing operations F, G, page 22.
NOTE:
This boiler is dispatched with the overheat
thermostat bulb positioned for FULLY PUMPED OPEN
VENTED OR SEALED systems. ONLY if the boiler is to be
used on a GRAVITY DHW system should the bulb of the
overheat thermostat be repositioned as described below, to
prevent nuisance operation of the overheat thermostat. If
boiler is fitted to a fully pumped system the spring clip in the
auxiliary pack can be discarded.
1.
Remove split pin retaining overheat thermostat (Fig.
21A) and pull bulb from pocket along with spacer,
discard spacer and split-pin.
2.
Carefully remove excess heat conductive paste from
bulb.
3.
Remove split grommet at the top right hand side of the
casing (Fig. 21 B).
4.
Carefully uncoil capillary and pass bulb through
grommet retaining hole, then attach to return pipe
using spring clip contained in auxiliary pack.
5.
Refit grommet ensuring that it makes a good seal
around the capillary. Ensure that the capillary is secure
in clips provided. Refer to Fig. 2.
6.
ENSURE that the system change-over switch in the
control box is set in GRAVITY DHW position.
ELECTRICAL
The boiler and all external control circuit wiring must be
supplied from the same single isolating switch and should
be fused at 3A.
Care must be taken to ensure that all wiring to the boiler is
kept clear of sharp edges and hot surfaces.
FIG. 22 PRINCIPLE OF WIRING
FIG. 23
ACCESS TO THE BOILER ELECTRICAL
TERMINAL BLOCK
The boiler terminal block which is situated in the control
box is not designed to accept wiring from all the on site
controls and therefore the installer will usually need to
incorporate a suitable junction box. This may not be
required if a Potterton Electronic Programmer is used as
this incorporates a junction box. The principle of wiring is
shown in FIG. 22.
Further information on wiring of system controls can be
found in the Control System, Pipework and Wiring Guide.
Remove control box securing screw and lower the control
box to gain access to the boiler terminal block.
