Commissioning Of The Boiler - Keston C36 Combi User, Installation And Servicing Instructions

WD388/0/2004

5. COMMISSIONING OF THE BOILER

Important: This condensing combination boiler contains components which could be damaged or
blocked by grease, dirt, solder etc., from the water system. The following
commissioning procedures must be followed precisely.
It is essential that combustion is checked at high and low rate , as per Section 5.7, using a
calibrated flue gas analyser set for the relevant gas type.
5.1 INITIAL FLUSHING
All waterways within the Keston C36 Combi and C36P Combi are either copper or high
alloy stainless steel. As a result water treatment chemicals for central heating boilers such
as Fernox MB1, Sentinel X100 or equivalent, are suitable. In any event reference must be
made to BS 7593 : Treatment Of Water In Hot Water Central Heating Systems.
a. Disconnect the boiler from the system at the flow and return connections and
temporarily link the flow and return pipes on the system.
b. Flush the entire system until clean water is discharged, free from dirt, flux, solder
etc. The use of a flushing chemical is recommended, e.g. Fernox Supafloc, or
equivalent.
Sludge and scale must be removed from an existing system. Boiler failure due to
system debris or sludge shall invalidate the guarantee.
c. Connect the system to the boiler and fill in accordance with Section 3.7 - CH &
DHW Water Systems. At this stage fill to a pressure of about 2.5 bar.
d. Check the complete system for water soundness. If leaks need to be rectified
using flux and solder, the system must be flushed cold again before proceeding.
e. Reduce the pressure to the Initial System Design Pressure. Vent the system
5.2 GAS SUPPLY
The complete gas installation up to the boiler service cock must be checked for
soundness. BS 6891.
5.3 ELECTRICAL INSTALLATION
Carry out preliminary electrical safety checks, i.e. Earth continuity, Polarity, Resistance to
Earth, Short Circuit using a suitable test meter.
5.4 LP GAS
The Keston C36 Combi and C36P Combi are supplied preset for the gas designated on
the boiler packing. No field conversion is possible. LPG installations must use C36P
Combi models only.
5.5 INITIAL FIRING
Important
Checking the gas pressure to the pre-mix burner requires a special procedure, outlined
below, which must be carried out.
a. Purge the gas supply in accordance with BS 6891.
b. Vent the water system.
Important:
The heat exchanger consists of corrugated tubes which can trap an air pocket.
Great care must be taken to ensure that water flow has been established through
the heat exchanger and thus ensuring no air pockets remain in the heat
exchanger and pipe work. Firing the boiler while an air pocket exists in the heat
exchanger could damage it.
c. Turn the gas service cock to ON.
d. Turn on the electrical supply, setting any external controls to call for heat.
e. Using the "+" button on the left hand side of the control panel, set the CH
temperature to 80C. After a few seconds the display will revert to show the actual
flow temperature of the boiler. Also press the "Summer" button until the green
light above this button is extinguished. Once a heating demand is received the fan
will start and the boiler will enter the pre-purge phase. During this phase the boiler
pump will also start to run. After 5 Seconds the boiler will start to spark and will
energise the gas valve. When ignition is achieved a dot will appear in the lower
right corner of the digital display to show the boiler is alight.
If an air lock or other blockage is present the unit may go to overheat or water
pressure lockout. This will be indicated by the display flashing error code "E03" or
Installation & Servicing Instructions
Chapter 5 : Commissioning The Keston C36 Combi & C36P Combi Boilers
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