Potterton Derwent Compact Plus Installation, Operation & Maintenance Manual page 20

SECTION 5
PAGE 18
Fig. 21A – Honeywell VR4601Q Gas Valve
Adjustment screw for
Cap
High Fire
Ionisation Current Check
Switch the boiler off at its on/off switch and at the
main isolator. Connect a micro ammeter into the
ionisation cable in between the electrode and cable.
Switch on the main isolator and the burner on/off
switch and after 15 seconds the ignition spark should
be heard followed by lighting of the pilot burner. The
micro ammeter should read approximately 3 - 4µA.
Switch off the main isolator and the on/off switch and
remove the micro ammeter connections.
Ventilation Checks
For boiler houses with natural ventilation, the area of
the grilles should be checked against the notes given
on Ventilation in Section 3.
For boiler houses with mechanical ventilation, the
suitability of the ventilation and extract system should
be checked against the notes given on Mechanical
Ventilation in Section 3.
In addition, the installer must check that it is not
possible for the boiler to operate if either the
ventilation or extract fans are not running.
THE BOILER SHOULD
WITHOUT ADEQUATE VENTILATION.
Operation Of Ancillary Controls
After lighting the boiler the operation of the above
mentioned controls, eg. clock and thermostats, should
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
Valve Adjustment under
Cap
NOT BE OPERATED
POTTERTON COMMERCIAL PRODUCTS DIVISION
DERWENT COMPACT PLUS - CONDENSING
be checked.
To Shut Down Boiler
1. Temporarily - Switch the on/off switch to "OFF".
Switch off the electrical supply.
2. Long Periods - As above but in addition turn off
the service cock at the gas meter.
Boiler Maintenance
It is essential for efficient and trouble free operation
that the boiler plant is regularly maintained. This must
be carried out by qualified and experienced engineers
and in the case of gas fired appliances attention is
drawn to the mandatory requirement of CORGI
(Confederation
registration of personnel undertaking work on these
appliances. This facility is available from Potterton
Commercial Division, details are available from
Regional Offices listed on the back page back of this
manual.
Boilers should be serviced and re-commissioned as a
minimum on an annual basis but frequency may
depend on usage and application of the boiler.
It is strongly advised that a maintenance contract be
entered into with Potterton Commercial Division to
ensure that the boiler/burner unit is correctly and
properly maintained.
WARNING Isolate the electrical and fuel supplies
before attempting any maintenance work.
Following completion of maintenance on the boiler the
boiler should be re-commissioned.
Boiler Cleaning
At every service visit the boiler should be cleaned as
detailed below and the soundness of the gas control
assembly must be checked. The boiler should be fully
re-commissioned as described below with attention
also paid to -
1 The effectiveness of natural and mechanical
ventilation and in particular the safe operation of
an air flow switch on a mechanical ventilation
system.
2 That the
adequately
combustion and that there is no spillage of flue
products.
3 That the burner gas pressure is correct and that
the boiler is still on rate.
4 That the low pressure switch on a booster
of Registered Gas
chimney system is
evacuating the products
Installers)
sound and
of