Filling And Draining - Rinnai Demand Duo Installation Manual

Filling and draining

Do not turn on the pump or system until the cylinder is completely full of
water. Damage to the system as a result of not following this instruction
will void any warranty.
IMPORTANT
Filling
1. Flush the cold water inlet pipe to remove any debris before final connection to the cold
water inlet of the Demand Duo cylinder.
2. Ease the TPR valve open to expel air while the cylinder is filling with cold water.
3. Slowly open cold water expansion valve on the cold water supply pipe.
4. Allow cylinder to fill.
5. Check all connections for water leaks and tighten as required.
6. Prime circulating pump before start up.
7. The thermostat on the Demand Duo cylinder is set to 65 °C and the Rinnai INFINITY is set
to 75 °C. If the cylinder thermostat does not appear to be set correctly the thermostat may
need to be reprogrammed—refer programming sheet available within the technical section
of the Demand Duo product on the Rinnai website or contact Rinnai for assistance.
If hotter water is required the cylinder and the Rinnai INFINITY dip switches will need to be
adjusted.
8. Plug 3-core flex into suitably earthed general power outlet (GPO). Turn on power supply. The
thermostat will display the current water temperature in the cylinder, the pump should start
and the Rinnai INFINITY units should ignite.
9. The Rinnai INFINITY units will continue to operate until the thermostat reaches 65 °C. Once
the set temperature has been reached the thermostat will turn off the primary circulating
pump.
Draining
1. Isolate power supply to the Demand Duo system.
2. Close the cold water isolation valve.
3. Ease the TPR valve open to expel air.
4. Remove cap on the cold water drain valve if no drain line is fitted.
5. Connect a hose or similar to allow water to drain to a safe location.
6. Open cold water drain valve and allow water to drain from the system.
14 | Demand Duo CFHW with storage backup installation guide: 12583-B