Worcester C1, Installation And Servicing Instructions

Remove  the  clip-on  facia  bottom  cover  and  the  controls
connections cover. Refer to Fig 29.
Slide down the access panel to display the mode switch and the
adjusting tool. Refer to Fig 37.

12.6

Checking the Burner Pressure

Check that all the radiator valves are open.
Check  that  the  system  is  pressurised  and  set  to  the  required
pressure as indicated on the gauge.
Set the temperature control knobs to maximum and the 
clock/programmer to operate continuously.
Turn on the gas and electricity supplies.
Set the mode switch to MAX using the mode adjuster tool. 
Refer to Fig 37 and 38. 

NOTE: Two red lights will flash rapidly

on the facia.

A  continuous  spark  will  occur  until  the  burner  is  alight  and
sensed  by  the  control  circuit.  The  burner  will  remain  at  its
maximum domestic hot water pressure for one minute. Refer to
Table 1.
It should not be necessary for the gas valve to be adjusted.
Note:  The  burner  pressure  is  factory  set  and  if,  after  checking
that  the  dynamic  (working)  supply  pressure  is  sufficient  i.e.
18.0mb  approx,  at  the  gas  valve  inlet  pressure  test  point,  the
correct  pressure  cannot  be  obtained  then  Worcester  Heat
Systems Service Department should be contacted.
If  the  appliance  does  not  light  then  check  that  it  is  not  in  the
‘lock-out’ state by pressing the reset button. Refer to Fig 39.
Set the mode switch to Normal.
The  burner  pressure  will  drop  to  the  minimum  setting  and  will
ramp  up  to  the  maximum  central  heating  pressure  appropriate
to the appliance and the gas . Refer to Table 1. It should not be

necessary for the central heating potentiometer to be adjusted to
change  the  burner  pressure.  If  adjustment  is  required  then  the
adjusting  tool  is  used  to  alter  the  setting  of  the  potentiometer.
Refer to Fig 38.
Set  the  mode  switch  to  MIN. 

NOTE:  Two  red  lights  will  flash

rapidly on the facia.

The  burner  pressure  will  drop  to  the  minimum  pressure
appropriate  to  the  appliance  and  the  gas  for  both  the  central
heating  and  domestic  hot  water  modes.  Refer  to  Table  1.  It
should not be necessary for the central heating potentiometer to
be adjusted.
Test  for  gas  soundness  at  the  joint  between  the  burner  and  the
gas valve with leak detection fluid.
Set the mode switch back to Normal.
Turn the electricity supply off and then back on to reset the controls.
Replace the facia cover panels.

12.7

Domestic Hot Water

Turn  the  central  heating  temperature  control  knob  fully  anti-
clockwise. Refer to Fig. 39.
Open a hot tap near the appliance. The burner will light and go
to  the  maximum  burner  pressure  appropriate  to  the  appliance
and the gas . Refer to Table 1.
Gradually close the tap and check that the burner pressure falls.
Fully open the tap and check that the pressure rises.
Close the tap and check that the burner goes out.
The fan may continue running until the appliance has cooled to a
pre-set temperature.

12.8

Central Heating

Check that all the radiator valves are open.
Check  that  the  system  is  pressurised  and  set  to  the  required
pressure as indicated on the gauge.
Check that the clock/programmer is set to operate continuously.
Set  the  room  thermostat  and  the  central  heating  temperature
control to maximum.
The burner will light and the appliance will modulate its output
from minimum to maximum over a period of about two minutes.
Check that all the radiators are heating up evenly.
Shut  down  all  but  one  of  the  radiators  and  observe  the  burner
pressure  fall.  Open  all  the  radiators  and  check  that  the  burner
pressure rises.

12.9

Balance  the  system  to  give  a  temperature  differential  of

11°C. A non-adjustable by-pass is fitted to the appliance.

12.10

Set the room thermostat to minimum and check that the

burner  goes  out.  Reset  the  room  thermostat  to  maximum  and
the  burner  will  re-light  and  follow  the  normal  operating
procedure.
Turn off the gas service cock. The burner will go out but sparking
from  the  electrode  will  continue  for  10  seconds  when  the
appliance will ‘lock-out’. After 60 seconds carefully open the gas
service  cock,  press  the  reset  button  and  observe  the  burner  re-
light and follow the normal sequence of operation. Refer to Fig 6
and 39.
Turn  off  the  gas  service  cock  and  the  electricity  supply  to  the
appliance.
Drain the system while the appliance is hot.
Refill, vent and re-pressurise the system as described in Section
12.1  preceding,  adding,  if  necessary,  a  suitable  proprietary
inhibitor.  Further  information  is  available  from  Betz  Dearborn
0151 420 9563 or Fernox 01799 550811.

12.11

Domestic Hot Water and Central Heating

Set all controls to maximum.
Turn on the electricity supply to the appliance and open the gas
service cock at the appliance.
The burner will light and heat will pass into the system. Turn on
a hot tap and check that hot water is soon discharged from the
tap. Close the tap.
The  appliance  will  then  return  to  the  central  heating  mode  and
automatically balance with the system requirements.
Turn off the appliance.

12.12

Completion of Commissioning

Disconnect the pressure gauge and tighten the test point screw.
Restart  the  appliance  and  check  for  gas  soundness  around  the
test point screw.

19

Fig.37. Mode control cover

Fig.38. Mode adjustment

Facia

Mode adjuster

Mode adjustment cover

Max/Min switch

Central heating limit
potentiometer 

Not operational