Connections - Rinnai Demand Duo Installation Manual

Connections

Expansion control valve (ECV)
The Demand Duo cylinder comes with an Expansion Control Valve (HT575) set to 700 kPa. This
valve allows for expansion of the water in the flow and return during the initial heat-up period.
This should be fitted to the cold water supply line.
TPR valves
Two 850 kPa TPR valves are supplied and fitted to a 20 mm fitting near the top of the cylinder.
Relief valve drain lines
Connect an independent 20 mm copper tube relief valve drain line to the TPR valve outlets.
Drain should be installed with a continuous fall toward a visible discharge point over a drain or
gully in accordance with AS/NZS 3500.4 sections 5.8 and 5.9.
• Drain line should not exceed 9 m in length
• Valves or other restrictions should not be installed with the relief vent line
• TPR valve drain line should not be joined to other drain lines
Return pump
A secondary or building return pump may be installed in conjunction with the Demand Duo hot
water system. Return line from the building loop is connected to the 32 mm return connection.
This is located just above the cold water inlet connection on the left hand side of the Demand
Duo cylinder.
If the secondary pump is not used a 32 mm brass plug should be fitted to the 32 mm return
connection, located just above the cold water inlet connection.
Install an effective filter to the circulating loop return line.
Gas connection
Check gas type of the Rinnai INFINITY matches the gas supply available on site.
Ensure gas pipe sizing is adequate to deliver the required volume/pressure. The pipe size used
on the inlet fitting is no indication of the pipe size required. Refer to appropriate pipe sizing
chart in AS/NZS 5601.1.
Gas meter or LPG cylinders and regulator should also be of a suitable size to ensure sufficient gas
supply to the gas installation.
Purge gas line and ensure removal of debris prior to final connection. Check for gas leaks using
suitable methods as listed in AS/NZS 5601.1
Demand Duo Demand Duo CFHW with storage backup installation guide: 12583-B | 9