Exchanging A Boiler; Electrical Installation; Initial Firing; Combustion Testing - Keston Celsius 25 Installation And Servicing Instructions

WD209/1/2000
Ensure connection is made such that if the cable slips in its anchorage the current
carrying conductors become taut before the earthing conductor.
3.9

EXCHANGING A BOILER

Before removing an existing boiler add Fernox Supafloc , or equivalent cleaning agent, in
accordance with the manufacturers instructions. Open all radiator valves and fire the
boiler. When the system is fully heated, shut off the gas supply and drain down the central
heating system.
Important
The Celsius 25 condensing boiler contains components which could be damaged or
blocked by grease, dirt or solder etc. It is essential that sludge or scale is removed from
an existing system.
The guarantee provided with the Keston Celsius 25 does not cover damage caused by
system debris or sludge.
Connect the new boiler as instructed in this manual and fit in accordance with Sections
3.1 to 3.8
For sealed systems, fill to a pressure of about 2.7 bar. Check the complete system for
water soundness. If leaks need to be rectified using flux or solder the system must be
flushed cold again before proceeding.
Reduce the pressure to the Initial System Design Pressure for sealed systems, if
applicable. Vent the system.
Gas Supply
The complete gas installation up to the boiler service cock must be checked for
soundness. BS 6891.

Electrical Installation

Carry out preliminary electrical safety checks, i.e. Earth continuity, Polarity, Resistance to
Earth, Short Circuit using a suitable test meter.

Initial Firing

The gas pressure setting is factory adjusted to within the required range and does
not need re-adjustment. If the reading is incorrect then check such factors as soundness
of the air and flue pipe joints, pressure sensible joints and the gas inlet pressure
(minimum 18 mbar required for Natural Gas and 31 mbar required for LP gas). If all joints
are sound and the gas inlet pressure is satisfactory set the gas pressure and check the
gas input. Full details of this procedure are given in Section 4.8 Timing The Gas Meter.

Combustion Testing

It is advisable on all installations that the combustion quality is checked by measuring the
carbon dioxide (CO
Combustion Testing. Badly tuned combustion will lead to reduce the life of the boiler and
invalidate the warranty.
Installation & Servicing Instructions
Chapter 3 : Installation
N - Blue wire (Neutral) for 3A permanent and 2A switched
supplies
PL - Brown wire (Live) 3A permanent supply
- Yellow/Green Wire (Earth)
SL - Brown wire (Live) 2A switched supply.
OR
SL & SL(LINK) -Link connection via volt free external controls
LO - To external 230V remote lockout monitoring (optional)
RUN - To external 230V remote run monitoring (optional)
), or oxygen (O
2
) level. This procedure is detailed in Section 4.9
2
The Keston Celsius 25 & 25P
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