Trianco Aztec Gold, Installation & Opersting Instructions, Page: 20 / 22

PARTS REPLACEMENT (cont.)
PRESSURE SAFETY SWITCH REPLACEMENT
(Fig. 23)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Disconnect the three wires from the top of the pressure
safety switch.
5) Unscrew pressure safety switch and replace with a new
unit, re-fitting in reverse order.
6) Re-fill the system as described on pages 7/8 , and open
isolating valves.
Notes: Do not over-tighten connections to manifold as this
could lead to thread damage.
Ensure a suitable thread sealant is used when screwing
switch into position.
EXPANSION VESSEL REPLACEMENT (Fig. 24)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Unscrew the expansion vessel and replace with a new
unit, re-fitting in reverse order. Ensure a suitable thread
sealant is used on all joints.
5) Re-fill the system as described on pages 7/8 , and open
isolating valves.
PUMP HEAD REPLACEMENT (Fig. 25)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Disconnect the pump power supply cables from the
terminal block and unscrew pump head.
5) Clean any deposits from the inside of the body and
replace the 'o' ring seal, if necessary.
6) Replace the pump head with a new unit, re-fitting in
reverse order.
7) Re-fill the system as described on
pages 7/8
, and open
isolating valves.
20
FIG. 23 - PRESSURE SWITCH
FIG. 24 - EXPANSION VESSEL
FIG. 25 - PUMP HEAD