Rinnai E50C Installation & Servicing Instructions Manual page 17

Boiler system fl ushing
- Boiler system fl ushing (Not Boiler heat exchanger)
When replacing an existing boiler the heating system should be fl ushed with
the old boiler in place before the new boiler is added to the system. If the old
boiler has already been removed a bypass must be piped in when the new boiler
is installed in order to facilitate the fl ushing of the system.
The boiler must be valved off from the system, while the system is fl ushed. No
system cleaner should ever enter the boiler heat exchanger due to its caustic
nature which could damage the heat exchanger.
1. Close the shutoff valves on both the supply and return connections on the plumbing
kit (V1 and V2).
2. Open the bypass valve (V4).
3. Connect pump outlet hose (H1) to the purge station (BD1) and connect H2 to the
inlet of the pump and place the other end in the pail.
4. Connect drain hose (H3) to the return side purge station (BD2).
5. Pour the system cleaner into a pail and follow the system cleaner instructions on
circulation time and volume to be added to the system.
6. Close the valve (V3)
7. Operate the pump (P1) and circulate the cleaner through the system for required
time as established by the cleaner manufacturer.
8. Once the time required by the system cleaner manufacturer has been met place
the hose (H3) in a drain.
9. Close the purge station (BD1)
10. Open the auto feed on the system (F1) and allow water to rinse the system for
whichever is greater; 10 minutes or the required rinse time by the system cleaner
manufacturer.
P
T
V1 V2
V4
BD1 BD2
V3
P
F1
H1
CP
H3
H2
System cleaner
fi g. 7
17