User Instructions - Jet 120i Installation & Servicing Instructions Manual

User Instructions

Warnings
I F W A T E R D I S C H A R G E S F R O M T H E
TEMPERATURE/PRESSURE RELIEF VALVE ON
CYLINDER SHUT DOWN THE BOILER. DO NOT
TURN OFF ANY WATER SUPPLY. CONTACT
A COMPETENT INSTALLER FOR UNVENTED
WATER HEATERS TO CHECK THE SYSTEM.
DO NOT TAMPER WITH ANY OF THE SAFETY
VALVES FITTED TO THE SYSTEM. IF A FAULT IS
SUSPECTED CONTACT A COMPETENT INSTALLER.
Benchmark
The cylinder is covered by the Benchmark Scheme
which aims to improve the standards of installation
and commissioning of domestic heating and
hot water systems in the UK and to encourage
regular servicing to optimise safety, efficiency and
performance.
Benchmark is managed and promoted by the
Heating and Hotwater Industry Council. For more
information visit www.centralheating.co.uk.
Please ensure that the installer has fully completed
the Benchmark Checklist (pages 20 & 21) of this
manual and that you have signed it to say that
you have received a full and clear explanation of its
operation. The installer is legally required to complete
a commissioning checklist as a means of complying
with the appropriate Building Regulations (England
& Wales).
All installations must be notified to Local Area
Building Control either directly or through a
Competent Persons Scheme. A Building Regulations
Compliance Certificate will then be issued to the
customer who should, on receipt, write the
Notification Number on the Benchmark Checklist.
This product should be serviced regularly to optimise
its safety, efficiency and performance. The service
engineer should complete the relevant Service
Record on the Benchmark Checklist after each
service.
The Benchmark Checklist may be required in the
event of any warranty work.
Flow Performance
When initially opening hot outlets a small surge in
flow may be noticed as pressures stabilise. This is
quite normal with unvented systems. In some areas
cloudiness may be noticed in the hot water. This is
due to aeration of the water, is quite normal and will
quickly clear.
16
Temperature Controls - Indirect Units
The cylinder units are fitted with an indirect thermostat
and thermal cut-out. These controls must be wired in
series with the 2 port motorised zone valve supplied
to interrupt the flow of primary water around the
heat exchanger coil when the control temperature
has been reached. The controls are located within
the lower terminal housing along with the immersion
heater thermostat. The thermostat is factory set to
give a water storage temperature of approx. 55°C
to 60°C. Access to the thermostat can be made by
opening the terminal housing cover - DISCONNECT
THE ELECTRICAL SUPPLY BEFORE OPENING
THE COVER. Temperature adjustment is made by
inserting a flat bladed screwdriver in the adjustment
knob and rotating. The minimum thermostat setting
is 12°C. The adjustment represents a temperature
range of 12°C to 72°C (Fig. 07, page 11). If in any
doubt contact a competent electrician.
An immersion heater is also provided for use should
the indirect heat source be shut down for any purpose.
The immersion heater control temperature is set
using the immersion heater thermostat.
DO NOT bypass the thermal cut-out(s) in any
circumstances.
Operational Faults
Operational faults and their possible causes are
detailed in the Fault Finding section of this book. It
is recommended that faults should be checked by
a competent installer.
The air volume within the cylinder will periodically
require recharging to ensure any expanded water is
accommodated within the unit. A discharge of water
INTERMITTENTLY from the pressure relief valve will
indicate the air volume has reduced to a point where
it can no longer accommodate the expansion. To
recharge the air volume:-
i) Turn off the heat source to the cylinder via
programmers / immersion isolation switch(es).
ii) Turn off the water supply to the cylinder by turning
off the isolating valve at the cylinder, if fitted or the
main incoming supply to the house.
iii) Open the lowest hot tap supplied by the cylinder.
iv) Hold open the temperature and pressure relief
valve until water ceases to run from the tap and
gurgling noise at the valve stops.
v) Close the temperature and pressure relief valve.
vi) Turn on the water supply to the cylinder
vii) The air volume will be automatically recharged
as the unit refills. If after following the above actions
water still discharges from the pressure relief valve,
further advice should be sought from a competent
installer or Technical Support