Dhw Expansion Tank; Installing A Thermostatic Mixing Valve - Rinnai E75CRN Installation & Servicing Instructions Manual

6.5.3
6.5.4
DHW piping with thermostatic mixing valve
24

DHW Expansion Tank

A domestic water expansion tank could be required by local code. Check local code
to determine if it is required.
If a combi boiler is installed in a closed water supply system, such as one having a
backflow preventer in the cold water supply line, means shall be provided to control
thermal expansion. Contact the water supplier or local plumbing inspector on how to
control thermal expansion.

Installing a Thermostatic Mixing Valve

A thermostatic mixing valve shall be installed on all E combi boilers on the domestic
hot water side to prevent scalding. This valve will regulate the water temperature
leaving the brazed plate heat exchanger. See the figure 11 for the suggested piping.
DANGER
Hot water can be dangerous, especially for infants or children, the elderly,
or infirm. There is hot water scald potential if the thermostat is set too high.
Water temperatures over 125º F (51º C) can cause severe burns or
scalding resulting in death.
Hot water can cause first degree burns with exposure for as little as:
3 seconds at 140º F (60º C)
20 seconds at 130º F (54º C)
8 minutes at 120º F (48º C)
Test the temperature of the water before placing a child in the bath or
shower.
Do not leave a child or an infirm person in the bath unsupervised.
fig. 11