IDEAL LOGIC + Combi 24 Installation And Servicing page 37

40 gENERAL ChECKs
Make the following checks for correct operation in:
DOMEsTIC hOT WATER (DhW) MODE
1. Fully open all DHW taps in turn and ensure that water flows
freely and that the mode knob is either in summer or winter
position. The boiler will display
"hot water" - "temperature XX
Efficiency"
where the temperature shown is the current Domestic Hot
Water temperature.
When the burner is lit the light above the display will be on.
2. 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 C at the flow rate stated on page 6 under
o
"operation".
3. Reduce the DHW draw-off rate to about 3 l/min (0.7gpm)
and check that the boiler modulates to deliver DHW at
approximately 64 C (with the DHW temperature control
o
knob set to maximum).
4. Close the DHW tap and check that the main burner
extinguishes. The pump should overrun for 60 seconds
during which the boiler will display "Pump overrun". The
fan will then continue to run for a further 3 minutes during
which the boiler will display "Fan Post Purge" after which
the boiler will display one of the following "standby mode"
- "summer mode" - "winter mode" depending on the
position of the mode knob.
Note. On systems in excess of 2 bar inlet pressure a water
pressure governor may be required to prevent water noise.
WATER CIRCULATION sysTEM
1. With the system COLD, check that the initial pressure
is correct to the system design requirements.
For pre-pressurised systems, this should be 1.0 bar.
2. With the system HOT, examine all water connections
for soundness. The system pressure will increase
with temperature rise but should not exceed 2.5 bar.
3. With the system still hot, turn off the gas, water and
electricity supplies to the boiler and drain down to
complete the flushing process.
Note: A flushing solution should be used during the
flushing procedure. Flushing solutions: Fernox
Superfloc, Sentinel X300 (new systems) or X400
(existing systems). Refer to Frame 5.
4. Refill and vent the system, add inhibitor (see Frame
5), clear all air locks and again check for water
soundness.
5. Reset the system initial pressure to the design
requirement.
6. Balance the system. Refer to Frame 4.
7. Check the condensate drain for leaks and check that
it is discharging correctly.
+
Ideal Logic Combi -
INsTALLATION
c" - "high
o
Installation and Servicing
Ch & DhW MODE
1. Ensure the CH controls are calling for heat and that the
boiler mode knob is in the winter position and the CH flow
temperature control knob is in the maximum position. The
Boiler will display
"central heating" - "radiator temp XXc"
where the temperature shown is the current flow temperature.
When the burner is lit the light above the display will be on.
2. Fully open the DHW tap and check that hot water is delivered.
The boiler will display "hot water" - temperature XX
- high Efficiency"
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 Tables 2 and 3 for gas rates.
4. Close the DHW tap. The burner should remain on and the
boiler will display "central heating" - "radiator temp
XXc".
5. Set the central heating external controls to off. The burner
will go off and the fan and pump continue to run for 4 minutes.
The boiler will display "Pump overrun" after which the
boiler will display one of the following: "standby mode"
- "summer mode" - "winter mode" depending on the
position of the mode knob.
6. Check the correct operation of the timer (if fitted) and all other
system controls. Operate each control separately and check
that the main burner responds.
Note. The temperature displayed "XXºC" is that
measured at that moment, not the set temperature.
8. Finally, set the controls to the User's requirements.
Notes.
1. If the pump has not operated in the last 24 hours it will run
briefly to prevent seizure
2. If the diverter valve has not operated in the last 24 hours
it will be operated briefly to prevent seizure. These two
operations will not occur at the same time.
WATER TEMpERATUREs
Temperatures can be selected using the CH and DHW thermostats.
Knob setting Ch Flow Temp
Max
Min
DhW Outlet Temp
o o o o
C ( F) C ( F)
80 (176) 64 (147)
45 (113) 40 (104)
c"
o
37