27
Part 1 - General Safety Information
Cap this fitting
when not in use
NOTE:
In piping applications utilizing a single zone, it is recommended that the installer use flow / check valves with weighted seats at or near the
appliance to prevent gravity circulation.
NOTES:
1. This drawing is meant to show system piping concept only.
Installer is responsible for all equipment and detailing required by
local codes.
2. The minimum pipe size of DHW piping should be ¾” diameter and
CH piping should be 1” in diameter.
3. Circulators are shown with isolation flanges. The alternative is
standard flanges with full port ball valves. Purge valves can be used
with circulator flanges as an alternative.
4. Install a minimum of 12 diameters of straight pipe upstream of all
circulators.
5.
VERY IMPORTANT
– Minimum flow rates outlined in this manual
(2 gpm) must be maintained through the heat exchanger to
minimize short cycling.
6. In a valve-based system, each heating zone has a zone valve which
opens when that zone calls for heat. Each zone thermostat is
wired to its corresponding zone valve. Contacts in the zone valves
provide a signal to the boiler to operate when there is a call for
heat.
7.
Unit is equipped with built-in primary pump for the heating
loop.
This pump is sized to ensure proper flow rate through the
boiler heat exchanger and related piping.
8. IWH Applications - a mixing valve is recommended if the DHW
temperature is set above 119
o
F.
9. For direct (not primary / secondary) piping applications, it is
required to install the expansion vessel on the return side of the
boiler as illustrated.
The piping will not support the weight of the circulators. Refer to
the circulator manufacturer’s instructions to properly support the
circulator. Failure to comply with these instructions could result in
property damage, severe personal injury, or death.
Figure illustrates the basic plumbing requirements for a TRX150
/ TRX199 boiler installation without an external Central Heating
circulator; the boiler’s internal circulator delivers flow to the heating
system. Application is limited to zone valve (or non-circulator)
distribution systems with small flow requirements (e.g. systems
requiring no more than 9 gpm at 9 ft. of head pressure).
WARNING
NOTICE
Figure 14 - Boiler without Central Heating Circulator
Part 4 - Water Piping
On TRX150 / TRX199 Models Only.
If the boiler is to be used only in Heating Mode (not connected to
an indirect water heater), cap the fitting as indicated in the figure
above. A cap is included with the boiler. The electrical connection of
the 3-way valve motor MUST BE DISCONNECTED while the boiler is
operating in central heating mode. This will lock the valve motor in
central heating mode and ensure freeze protection operates properly.
Failure to disconnect the valve may disable boiler freeze protection
and result in property damage.
CAUTION
For direct (not primary / secondary) piping applications, the expansion vessel must be
placed on the return side of the boiler as illustrated. Placement of flow resticting devices,
such as check valves, is prohibited between the boiler return and the expansion vessel.
Failure to place the expansion vessel as instructed, may result in the release of the
pressure relief valve, property damage, severe personal injury, or death.
WARNING
Summary of Contents for TRX150
Page 98: ...98 Maintenance Notes...
