LAARS Rheos+ RHHV - Install and Operating Manual - Manual (Page 16)

Rheos+ Boiler and Water Heater Page 15
medium is piped in parallel with the boiler with
appropriate valves to prevent the chilled medium from
entering the boiler.
The boiler piping system of a hot water heating
boiler connected to heating coils located in air
handling appliances where they may be exposed to
refrigerated air circulation must be equipped with flow
control valves or other automatic means to prevent
gravity circulation of the boiler water during the
cooling cycle.
A boiler installed above radiation level, or as
required by the authority having jurisdiction, must be
provided with a low water cutoff device either as a part
of the boiler or at the time of boiler installation.
4A.3 Freeze Protection – Boiler
Rheos+ units are not designed to be placed
outdoors, due to the potential for condensate to freeze
in the unit.
Proper precautions for freeze protection are
recommended for boiler installations in areas where
the danger of freezing exists.
Power outage, interruption of gas supply, failure
of system components, activation of safety devices,
etc., may prevent a boiler from firing. Any time a
boiler is subjected to freezing conditions, and the
boiler is not able to fire, and/or the water is not able
to circulate, there is a risk of freezing in the boiler
or in the pipes in the system. When water freezes,
it expands. This can result in bursting of pipes in the
system, or damage to the boiler, which could result in
leaking or flooding conditions.
Do not use automotive anti-freeze. Maintaining
a mixture of minimum 50% water and maximum
50% properly inhibited HVAC glycol, which contains
an antifoamant, is the preferred method of freeze
protection for Rheos+ boilers. The percentage of
glycol used in the Rheos+ boiler must not exceed
50%. Typically, this mixture will serve as burst
protection for temperatures down to approximately
–35°F (-30°C).
IMPORTANT NOTES : Different glycol products
may provide varying degrees of protection. Glycol
products must be maintained properly in a heating
system, or they may become ineffective. Consult
the glycol specifications, or the glycol manufacturer,
for information about specific products, maintenance
of solutions, and set up according to your particular
conditions.
For installations where temperatures are
expected to fall below 15°F inside the boiler cabinet,
the actuating gas valve must be equipped with a gas
valve heater, LAARS part number R2010100. Note
that some gas trains such as the IRI option may have
double actuators, and may require 2 gas valve heaters.
Section 4B
WATER CONNECTIONS —
RHEOS+ WATER HEATER
4B.1 Water System Piping —
Water Heater
Hot water piping should be supported by
suitable hangers or floor stands. Do not support piping
with this appliance. Due to expansion and contraction
of copper pipe, consideration should be given to the
type of hangers used. Rigid hangers may transmit
noise through the system resulting from the piping
sliding in the hangers. It is recommended that padding
be used when rigid hangers are installed.
The Rheos+ can be used with several different
types of readily available storage tanks. A pump
draws water from the storage tank and pumps the
water through the heater and back into the tank.
Pump-mounted units have a circulating pump built
into the water heater.
Pipe the outlet from the heater’s relief valve
such that any discharge from the relief valve will be
conducted to a suitable place for disposal when relief
occurs. Do not reduce line size or install any valves in
this line. The line must be installed to allow complete
drainage of both the valve and the line.
Suggested piping diagrams are shown in Figures
8, 9, 10, and 11. These diagrams are meant only as a
guide. Components required by local codes must be
properly installed.
The minimum inlet water temperature for the
Rheos+ is 50°F (10°C) to avoid condensing on the
copper coils.
4B.2 Hot Water Supply Piping —
Water Heater
Follow the tank manufacturer’s guidelines for
completion of the hot water system connections.
NOTE: A listed temperature and pressure relief
valve listed as complying with the Standard for
Relief Valves and Automatic Gas Shutoff Devices
for Hot Water Supply Systems, 1). ANSI Z21.22
latest edition, or 2). CSA 4.4, of suitable discharge
capacity must be installed in the separate storage
tank system.
If the Rheos+ water heater is installed in a
closed water supply system, such as one having a
backflow preventer in the cold water supply line, the
relief valve may discharge periodically, due to thermal
expansion. Means (such as a properly-sized expansion
tank) shall be provided to control thermal expansion.
Contact the water supplier or local plumbing inspector
on how to control this situation.