HAMWORTHY HEATING LTD
WESSEX-HE 200 BOILER
500001008/K
14
caused the flame to “lift off” the combustion head and
hence allow the flame probe to lose contact with the
flame.
8. Burner starts, runs but subsequently goes to
lockout.
Coloured programme indicator stopped at
end of green and start of white sector.
a) Check for interruption in gas supply.
b) Check for failure of combustion air supply.
c) Check flame probe position for proper contact with
flame.
d) Check flame probe insulator for soundness.
e) If necessary, change control box.
12.3 Causes of Lockout
1.
No Ignition.
2.
Ignition not in correct place, check electrode
settings and ceramic insulator for cracks or damage.
3.
No gas supply.
4.
Gas valve(s) not opening.
5.
Failure of combustion air supply.
6.
Incorrectly positioned flame probe, poor earth
contact with flame, interference to flame signal from
ignition spark.
7.
Faulty control box.
13.0 SERVICING INSTRUCTIONS
13.1 General
Regular periodic servicing is recommended,
preferably by a Hamworthy appointed person.
WARNING: ISOLATE THE ELECTRICAL
SUPPLIES TO THE BOILER BEFORE SERVICING
OR COMPONENT EXCHANGE PROCEDURE AND
TURN OFF THE MANUAL GAS VALVE TO THE
MODULE BEING SERVICED. VOLT FREE
CONTACT ELECTRICAL SUPPLIES MUST ALSO
BE ISOLATED IF FITTED.
13.2 Annual Service
NOTE:
A competent plant maintenance engineer
should check and ensure that the flue, its support and
terminal, the ventilation to the boiler house, safety
valve, drain, water filter if fitted, pressure gauge, etc.
are in a serviceable and working condition and still
comply with the relevant and aforementioned
standards and Codes of Practice.
13.2.1
Remove controls cover by unscrewing the
central 'Pozidrive' screw and releasing the top of the
cover which hooks behind the closing plate around
the top water connection (Wessex-HE 200 only). The
cover is then drawn forward and removed.
The Wessex-HE County cover is removed in a similar
way however the closing plates fitted around the
water connections must first be removed.
At this stage in any servicing of the boiler, it may be
advantageous, with regard to increasing the working
space and preventing possible damage, to remove
the boiler fascia plate. This can be achieved by
locating and removing the 2 counter-sunk socket
headed M4 screws situated below the fascia label.
The fascia remains connected via the cables to the
fuse, switch and neons, which are all removable
spade connections. Note position and colours of
cables before removal to facilitate reconnection.
NOTE:
If the fascia is left loose but connected, care
should be exercised to protect the cables rubbing on
the controls bracket.
13.2.2
Remove fan/mixing chamber and controller
assembly as described below: -
a) Disconnect
mains supply by pulling apart the
interlocking terminal block, see Figure No. 4,
releasing the cable clamps and disconnecting
the differential pressure switch earth cable at
the earth post. (If volt free contacts are fitted,
locate the relays mounted on the side of the
controls bracket and pull the white tabs
beneath the relay bases downwards to
disengage from the mounting rail).
