The method of connection to the mains electricity supply must facilitate complete
electrical isolation of the boiler, preferably by the use of a fused, unswitched three
pin plug and a shuttered socket-outlet, both complying with the requirements of
BS 1363. There must be only one common method of isolation for the boiler and
its control system.
The appliance must be connected to the 3A supply via a fused double-pole switch
having at least 3 mm (1/8 inch) contact separation in both poles, serving only the
boiler and the system controls.
The connection point to the mains supply should be readily accessible and
adjacent to the boiler, except for rooms containing a bath or a shower. Refer to
section 3.3 Position.
3.4.2
External Wiring & Controls
1.
The boiler is designed so that all control wiring is external to the boiler.
2.
Heating control signal inputs must the 230VAC "switched live" type unless
using a Keston Room Controller (see below)
3.4.2.1 Enhanced Control Options
Room Compensation (Opentherm)
A Keston Room Controller may be used to provide room compensated
control to ensure the boiler output is matched to the rooms requirements
at optimum boiler efficiency. This is only recommended for heating only
applications.
Weather Compensation
A Keston outside temperature sensor may be connected as an option.
The boiler will automatically detect this connection and will operate on a
"weather compensation" basis when receiving a heating demand signal
from the SL1 terminal or from a Keston Room Controller. Screened cable
(80% density) must be used to connect the outside temperature sensor.
3.5
BOILER SIZE SELECTION
The Q37 will automatically adjust heat output and pump speed to match the system
requirements at any given time. Efficiency and combustion levels are maintained at
optimum levels throughout the possible output range. The Q37 is therefore suitable for all
systems with a total heat load within the maximum range of the boiler.
3.6
GAS SUPPLY
A gas meter should be connected to the service pipe by the local gas region or their
contractor. An existing meter should be checked preferably by the gas region to ensure
that the meter is adequate to deal with the rate of gas supply required. Installation pipes
should be fitted in accordance with BS 6891.
Minimum/Maximum Gas Pressure:
Natural gas pressure before the gas valve must be maintained at between 18 mbar (7.2 in
WG) and 22 mbar (8.8 in) while the boiler is running.
WD500
Chapter 3 - Boiler Location
The Keston Q37 & Q37P Boilers
Installation & Servicing Instructions
Page : 12
Live
Neutral
Earth
Mains Supply
230V
Fused @ 3A
Room Thermostat
T6360B1028
1
2
3
KESTON
Qudos 37
L
N
E
SL1
Alarm
SL2
3.4.2 Wiring Example
OTC
OTC
To Keston
Ext. Sensor
[Optional]
OT
OT
To Keston
Room Controller
[Optional - instead of room thermostat]
