LAARS Rheos RHCV - Install and Operating Manual - Manual (Page 18)

LAARS Heating Systems Page 18
NOTE: This appliance must be installed in a closed
pressure system with a minimum of 12 psi (82.7kPa)
static pressure at the boiler.
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. Maintain 1" (2.5cm)
clearance to combustibles for hot water pipes.
Pipe the discharge of the relief valve (full size)
to a drain or in a manner to prevent injury in the event
of pressure relief. Install an air purger, an air vent,
a diaphragm-type expansion tank, and a hydronic
flow check in the system supply loop. Minimum fill
pressure must be 12psig (82.7kPa). Install shutoff
valves where required by code.
Suggested piping diagrams are shown in Figures
4, 5, 6, 7 and 8. These diagrams are meant only as a
guide. Components required by local codes must be
properly installed.
4A.2 Cold Water Make-Up — Boiler
1. Connect the cold water supply to the inlet
connection of an automatic fill valve.
2. Install a suitable back flow preventer between the
automatic fill valve and the cold water supply.
3. Install shut off valves where required.
NOTE: The boiler, when used in connection with a refrigeration
system, must be installed so the chilled 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 Water Flow Requirements — Boiler
A hydronic heating (closed loop) application
recirculates the same fluid in the piping system. As a
result, no new minerals or oxygen is introduced into
the system. To ensure a proper operating temperature
leading to long boiler life, a flow rate has been
established based on the fluid temperature rise for this
specific size boiler.
Pump-mounted boilers can be ordered for use in
primary secondary piping systems. The pumps used
are sized for the headloss through the heater, plus 30
4. Run gas supply line in accordance with all
applicable codes.
Note: If you have a boiler/water heater with a
normally open vent valve, install a vent line from
the vent valve to an outside location as required
by your installation code or IRI requirement. Do
not remove 3/4 inch pipe plug from the vent
valve if venting from the normally open vent
valve is not required by your installation code.
5. Locate and install manual shutoff valves in
accordance with state and local requirements.
6. A sediment trap must be provided upstream of
the gas controls.
7. All threaded joints should be coated with
piping compound resistant to action of liquefied
petroleum gas.
8. The appliance and its individual shutoff valve
must be disconnected from the gas supply piping
during any pressure testing of that system at test
pressures in excess of 1/2 PSIG (3.45kpa).
9. The unit must be isolated from the gas supply
system by closing its individual manual shutoff
valve during any pressure testing of the gas
supply piping system at test pressures equal to or
less than 1/2 PSIG (3.45kpa).
10. The appliance and its gas connection must be
leak tested before placing it in operation.
11. Purge all air from gas lines.
WARNING:
Open flame can cause gas to ignite and result in
property damage, severe injury, or loss of life.
NOTE: The Rheos appliance and all other gas
appliances sharing the gas supply line must be firing
at maximum capacity to properly measure the inlet
supply pressure. The pressure can be measured at
the supply pressure port on the gas valve. Low gas
pressure could be an indication of an undersized
gas meter, undersized gas supply lines and/or an
obstructed gas supply line. A bleed line from the
diaphragm-type automatic valve shall be vented per
local code requirements. Rheos units are equipped
with low and high gas pressure switches that are
integrally vent limited. These types of devices do not
require venting to atmosphere.
SECTION 4A.
Water Connections — Rheos Boiler
4A.1 Heating System Piping:
Hot Supply Connections — Boiler