28
INSTALLATION
isar -
Installation and Servicing
38 GENERAL CHECKS
CENTRAL HEATING (CH) & DOMESTIC HOT WATER (DHW)
MODE.
1. Ensure that the CH external controls are calling for heat.
The display should read:
after first satisfying DHW preheat if necessary. (
)
2. Fully open a DHW tap and check that hot water is
delivered.
The display should read:
3. Gas Rate
Check the boiler gas rate when the boiler is at full DHW
output.
Check at the gas meter, with no other appliance in use.
Refer to Table 3 for gas rates.
4. Close the DHW tap. The burner should go off and the
pump continue to run.
The display should read:
flashing
then
flashing
After 15 seconds the burner should relight, to supply central
heating.
The display should read:
37
INITIAL LIGHTING - continued
15. DOMESTIC HOT WATER
With the boiler firing, set the DHW thermostat knob (Y) to
maximum and fully open a DHW tap.
The boiler should continue to run and the LED display should
show status .
16. Ensure that with the boiler operating the dynamic gas pressure is
able to obtain maximum output. Refer to Table 2.
N.B. The principle of the 1:1 gas valve ensures that the isar
m30100 is able to deliver its full output at inlet pressures well
below those required by BS. 6891.
IMPORTANT
The gas input to the burner is regulated by the gas valve
according to the air flow produced by the fan. It is NOT user-
adjustable. Any interference to sealed settings on the gas valve
will adversely affect operation and render our warranty void.
17. Turn off the DHW tap.
18. Set the boiler on/off switch (A) to OFF.
19. Swing the control box into the servicing position.
Refer to Frame 44.
20. Remove the pressure gauge and tube. Tighten the
sealing screw in the pressure test point. Ensure a
gas tight seal is made.
21. Swing the control box back into its working
position and secure. Reconnect the ignition lead.
22. Refit the user control.
23. Refit the boiler front and bottom panels.
24. Switch the boiler on again.
DOMESTIC HOT WATER (DHW) MODE
1. With no call for CH or DHW the boiler should fire for a short
period to preheat the DHW plate heat exchanger.
The display should read
returning to
when the burner switches off.
Notes.
a.
If no DHW is drawn off, the boiler will fire periodically
for a short time, to maintain the plate heat exchanger
temperature.
b.
The DHW preheat operates 24 hours a day .
2. Fully open all DHW taps in turn and ensure that water flows
freely from them.
The display should read:
flashing
then
when the burner lights.
3. Close all taps except the furthest one from the boiler and check
that the boiler is firing at maximum rate.
This is factory set to give a DHW temperature rise of
approximately 35
o
C at the flow rate: 12.0 l/min (2.6 gpm)
4. Reduce the DHW draw-off rate to about 3 l/min (0.7 gpm)
and check that the boiler modulates to deliver DHW at
approximately 65
o
C.
5. Close the DHW tap and check that the main burner
extinguishes. The pump should overrun for a few seconds
and the display sequence should read:
When the pump stops the display sequence should read:
Note.
On systems in excess of 2 bar inlet pressure a water
pressure governor may be required to prevent water noise.
Make the following checks for correct operation in:
INST
ALLA
TION
Содержание isar m30100
Страница 1: ......
