88
NO DHW BUT CH OK
Ensure that the Timer and Cylinder Stat/Thermistor
are calling for heat (if a DHW Thermistor is used
see Frame 38 for setting DHW Temp.)
yes
Is there 230Vac at (C)?
There is no voltage from the
Timer/Cylinder Stat. This
is not a boiler fault. Ensure
voltage is supplied to the boiler
by correcting external wiring.
Rectify wiring
from boiler to
OpenTherm
device
no
yes
Does the system have a DHW Pump or Power Open
Diverter Valve?
Is the system correctly set for a Power
Closed Diverter Valve?
no
no
Set boiler correctly (See page 45)
yes
Is there 230Vac at (D)?
Check wiring from PCB to (D)
no
yes
yes
Does wiring to external DHW Pump have continuity and
is to the correct connections?
Rectify wiring to external DHW pump/valve
no
yes
Is the DHW Pump/Valve stuck
Replace the DHW pump/valve
no
(D)
(C)
yes
Is the boiler set for DHW priority (default setting)?
Set boiler for DHW priority (see Frame 41)
no
Is the boiler correctly set for a DHW Pump or Power
Open Diverter Valve?
no
yes
Is an OpenTherm device connected to the
boiler (note that the ideal programmable Room
Stat is an OpenTherm device)?
no
Does the wiring from the boiler to the
OpenTherm device have continuity?
yes
yes
no
Are the Timer and Cylinder Thermostat/
Thermistor calling for Heat?
no
Free the pump/valve
yes
To Next Page
Loading...
Need help?
General