Rheem 864 Series Owner's Manual And Installation Instructions page 47

FROST PROTECTION
The water heater has a frost protection system. The frost protection system will protect the water heater from
damage, by preventing ice forming in the waterways of the water heater, in the event of freezing conditions
occurring.
The frost protection system will be rendered inoperable if electrical power is not available at the water heater.
Damage to the water heater caused by freezing of the pipe work to or from the water heater is not covered
under the Rheem warranty. Refer to AS/NZS 3500.4 for precautions to be taken for installations in frost prone
areas. The water heater is not suitable for installation in areas where the ambient temperature falls below -
20°C (including wind chill factor).
The cold water line to the water heater must be insulated with suitable thickness insulation if freezing conditions
are likely to occur. The insulation must be fitted to the underside of the water heater and be weatherproof and
UV resistant if exposed.
MAINS WATER SUPPLY
Where the mains water supply pressure exceeds that shown in the table below, an approved pressure limiting
valve that does not have non-return valve characteristics (such as an RMC PSL series valve) is required and
should be fitted as shown in the installation diagram
Model
Relief valve setting
Max. mains supply pressure
Min. mains supply pressure *
* minimum water supply pressure required to achieve the
rated flow and performance
Notes:

It is not recommended to install this water heater with a low pressure water supply.

A minimum water supply pressure of 140 kPa is required to achieve the rated flow and performance of
the water heater.

If this water heater is installed as an in-series gas booster for a solar water heater, the maximum water
supply pressure to the solar water heater, without an expansion control valve (ECV), is generally 800 kPa,
however it may be less than this for some models. Refer to the Owner's Guide and Installation Instructions
supplied with the solar water heater for maximum mains supply pressure details.

If sludge or foreign matter is present in the water supply, it is recommended a suitable filter be incorporated
in the cold water line to the water heater.

This water heater is not suitable for connection to bore water or spring water unless a water treatment
device is fitted.
 "Water Supplies"
Refer to
(refer to page
27
1750 kPa
1000 kPa
140 kPa
on page 41 for further information on water chemistry.
47
INSTALLATION – WATER HEATER
57).