Page 79
10.2.2 System Filling
For all System and Combi boilers a filling point complete with a filling loop is supplied fitted
to the expansion vessel. The filling loop MUST be disconnected from the mains supply after
filling. A system pressure when cold of 1 bar is recommended. After filling, vent all air from
the system. The plastic plugs of the auto air vent(s) factory fitted to the boiler must be
loosened when filling the system in order to bleed the air from the boiler, then re-tightened
when filling is complete.
10.2.3 Combi Filling
When filling a combination boiler, the appliance must be switched off, and the diverting
valve red handle pressed and turned to the mid position to ensure correct filling of the
system and heat store.
10.2.4 System Pressure
Water loss from the system as indicated by a reduction in pressure on the pressure gauge
may be made up through the filling loop. In the first week of operation it is normal to see a
drop in system pressure. After this time the system pressure must be rechecked and the
system refilled. Failure to do so may lead to boiler faults.
Special attention must be given to the concentration of corrosion inhibitors in the system
water where there is a need for topping up or refilling. Inhibitor concentrations must be
restored to the concentrations specified by the inhibitor manufacturer.
Frequent or routine refilling and topping up of the system should not be necessary on an
ongoing basis and may prove harmful to the appliance. Should topping up prove necessary
on a frequent or routine basis you must contact Warmflow or your installer.
10.2.5 Pressure Relief Valve
Any pressure relief valve fitted to the boiler or system must be able to discharge externally
to a drain where the discharge can be seen but cannot cause any injury or damage. No
other valves should be positioned between the relief valve and discharge termination. The
pressure relief valve should be manually activated periodically in order to asses valve
opening, normally as part of servicing.
10.2.6 Low Pressure Switch
Where there is a catastrophic loss of water from the system the boiler thermostats may fail
to operate which would result in serious damage to the appliance. To prevent this it is
recommended that a low pressure cut out switch set at 0.3 bar is fitted to the system and
wired in series with the boiler limit thermostat. Combi models are factory-fitted with a
pressure switch as standard.
10.3 Combi Domestic Hot Water
10.3.1 Mains Water Pressure
To protect the appliance and to prevent excessive flow rates, a pressure reducing valve
must be fitted to limit the maximum supply pressure to 3 bar.
To Next Page
Loading...
