No Dhw But Ch Ok - Keston HEAT 2 45 Installation & Servicing

5.15 NO DHW BUT CH OK

Is there a 230V on SL2 input
If a tank thermistor is configured and
fitted in place of a cylinder thermostat,
check the connection continuity and
thermistor
R(25ºC) = 10,000 Ω
Is the resistance correct?
Is an OpenTherm device connected
to the boiler (note that the Ideal
programmable room stat is an
OpenTherm device)?
Is the DHW circuit set for day or in
a timed (on) period, or if it has an
OpenTherm device connected adn
configured for DHW check that it is
calling for DHW.
Does the system hav a DHW pump or
diverter valve?
Is the boiler correctly set for a DHW
pump or diverter valve?
Check the control signal for the pump
depending on the configuraiton.
1. 230V supply from isolate or boiler MFR
2. Volts free enable from MFR
3. 0-10V signal from boiler 0-10V output
(Rectify fault as required)
Installation & Servicing
SECTION 5 - FAULT FINDING
There is no voltage from the timer/cylinder stat. This
no
is not a boiler fault. Ensure voltage is supplied to the
yes
Check thermister and external wiring and replace as
no
yes
yes
no
no
yes
no
yes
no
yes
boiler by correcting external wiring.
necessary.
Does the wiring from the
boiler to the OpenTherm
device have continuity?
yes
Set the DHW system to call for heat
Check system for water circulation
Set boiler correctly
Rectify wiring from
no
boiler to OpenTherm
device.
73