Rinnai RUR98i - Connect Water Heater to Water Supply; Checklist for Plumbing

40 KBP Series Manual
Water drain plug
Condensate trap drain plug
Condensate drain line
Gas connecon
Cold water inlet
with lter
Hot water outlet with
bypass plug (or
bypass lter)
Pump drain plug
Check valve drain plug

Connect Water Heater to Water Supply
Water connecons to the tankless water heater
should follow all state and local plumbing codes.
If this is a standard installaon, refer to the “Piping
Diagram for Basic Installaon” in this manual.
1. Plumb water supply to the tankless water heater
on the 3/4” MNPT connecon at the boom of
the unit marked “Water Inlet”, which is the cold
water supply.
2. Plumb the building hot water supply to the 3/4”
MSPT connecon marked “Water Outlet”, which
is the hot water supply.
If a pipe cover will be installed, make sure water lines
to the water heater t properly.
Installaon of a potable water thermal expansion tank
is required.

□ Purge the water line of all debris and air by closing
the hot isolaon valve and opening the cold
isolaon valve and its drain. 
 Use a bucket or hose if
necessary.
□ Ensure that hot and cold water lines are not
crossed to the unit and are leak free.
□ Ensure that a pressure relief valve is installed with
a rang that exceeds the BTU input of the water
heater model. Refer to the rang plate on the
side of the water heater for BTU input.
□ Clean the water lter(s) by closing the cold and
hot water inlet isolaon (shut-o) valves. Put a
bucket under the lter(s) at the boom of the
water heater to catch any water that is contained
inside the unit. Unscrew the water lter(s). Rinse
the lter(s) to remove any debris. Install the
lter(s) and open the isolaon valves.
□ Check for proper water pressure to the water
heater. Minimum water pressure is 50 psi. Rinnai
recommends 60-80 psi for maximum
performance.
□ Ensure thermal expansion tank is properly
installed per local codes.