6
probe is not supplied with the GB models. A tank probe can be
used as an option to control loop temperature and unit staging.
Additionally, the Inlet Temperature Probe can be used as the loop
thermostat in some heating (GB) applications. These types of
controls connect to designated wires in the junction box at the rear
of the boiler.
Do not operate this boiler using the internal high
limits only, you must use an operating thermostat as mentioned
above.
Note: Additional 24V devices or Tank Probe must be identified
using Dip Switches on Central Control Board before they are
recognized as a part of the heating system. See table 5 and refer to
"Multi-Stage Firing and Control System" on previous page for more
information about dip switch settings.
CIRCULATING PUMP
The pump flow rate should not exceed the maximum
recommended flow rate, see table 4.
FOR HOT WATER SUPPLY SYSTEMS (GW models)
, ordered with
the circulator as an integral part of the boiler; the pump has been
lubricated at the factory, and future lubrication should be in
accordance with the motor manufacturer's instructions provided
as supplement to this manual.
FOR HOT WATER HEATING SYSTEMS (GB models or GW models
ordered without circulator)
, the circulator is NOT provided and
must be field-installed.
LOW WATER CUTOFF (Not Supplied)
If low water protection is required by the authorities having
jurisdiction, a low water cutoff switch should be installed
next to the boiler in the outlet water line as shown in
"HYDRONIC INSTALLATION" section. The switch should receive
periodic (every six months) inspection to assure proper operation.
A low water cutoff device of the float type should be flushed every six
months.
DRAIN VALVE (Not Supplied)
Additional drain valves must be obtained and installed on each
boiler and tank for draining purposes.
SAFETY RELIEF VALVES
Your local code authority may have other specific relief valve
requirements not covered below.
WARNING
THE PURPOSE OF A SAFETY RELIEF VALVE IS TO AVOID
EXCESSIVE PRESSURE WHICH MAY CAUSE TANK EXPLOSION,
SYSTEM OR BOILER DAMAGE.
TO AVOID WATER DAMAGE A DRAIN LINE MUST BE CONNECTED
TO A SAFETY RELIEF VALVE TO DIRECT DISCHARGE TO A SAFE
LOCATION. A DRAIN LINE MUST NOT BE REDUCED FROM THE
SIZE OF THE VALVE OUTLET AND IT MUST NOT CONTAIN ANY
VALVES BETWEEN THE BOILER AND THE RELIEF VALVE OR THE
RELIEF VALVE AND THE DRAIN EXIT. IN ADDITION, THERE
SHOULD NOT BE ANY RESTRICTIONS IN A DRAIN LINE NOR
SHOULD IT BE ROUTED THROUGH AREAS WHERE FREEZING
CONDITIONS MIGHT OCCUR. DO NOT THREAD OR CAP THE
DRAIN LINE EXIT. RESTRICTING OR BLOCKING A DRAIN LINE
WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE AND MAY
CREATE AN UNSAFE CONDITION. INSTALL A DRAIN LINE WITH
A DOWNWARD SLOPE SUCH THAT IT NATURALLY DRAINS
ITSELF.
If any safety relief valve is replaced, the replacement valve must
comply with the latest version of the ASME Boiler and Pressure
Vessel Code, Section IV (HEATING BOILERS). Select a relief valve
with a discharge rating NOT less than the boiler input, and a set
pressure NOT exceeding the working pressure of any component
in the system.
The storage tank temperature and pressure relief valve must
comply with the applicable construction provisions of the Standard
for Relief Valves and Automatic Gas Shut-off Devices for Hot Water
Supply Systems, ANSI Z21.22 or CSA-4.4 (and latest addendums).
The valve must be of the automatic reset type and not embody a
single-use type fusible plug, cartridge or linkage.
FOR HOT WATER HEATING SYSTEMS, the boilers are shipped
with a 50 psi pressure relief valve. This relief valve is factory
installed in the water outlet header of the boiler, see figure 1.
FOR HOT WATER SUPPLY SYSTEMS, the boilers are shipped
with a 125 psi pressure relief valve. This relief valve is factory
installed in the water outlet header of the boiler, see figure 1.
This ASME-rated valve has a discharge capacity that exceeds the
maximum boiler input rating and a pressure rating that does not
exceed the maximum working pressure shown on the boiler rating
plate.
In addition, an A.G.A. design-certified and ASME-rated temperature
and pressure (T & P) relief valve must be installed on each and
every water storage tank in the hot water supply system, see
figures 11 and 13.
The T & P relief valve should have a temperature rating of 210°F
(99°C), a pressure rating NOT exceeding the lowest rated working
pressure of any system component, and a discharge capacity
exceeding the total input of the water boilers supplying water to the
storage tank.
Locate the T & P relief valve (a) in the top of the tank, or (b) in the
side of the tank on a center line within the upper six (6) inches
(15 cm) of the top of the tank. The tapping shall be threaded in
accordance with the latest edition of the Standard for Pipe Threads,
General Purpose (inch), ANSI/ASME B1.20.1. The location of, or
intended location for, the T & P relief valve shall be readily
accessible for servicing or replacement.
INSTALLATION INSTRUCTIONS
REQUIRED ABILITY
INSTALLATION OR SERVICE OF THIS BOILER REQUIRES ABILITY
EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE
FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS
SUPPLY AND ELECTRICAL WORK ARE REQUIRED.
LOCATION
When installing the boiler, consideration must be given to proper
location. Location selected should be as close to the stack or
chimney as practical with adequate air supply and as centralized
with the piping system as possible. This location should also be
such that the gas ignition system components are protected from
water (dripping, spraying, etc.) during appliance operation and
service (circulator replacement, control replacement, etc.)
