LP-719 Rev. 000 Rel. 000 Date 6.25.20
23
Cap this fitting
when not in use
Primary/Secondary Piping Shown - See
Note 2
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.
Figure 14 - Boiler with Single Central Heating Circulator
NOTICE
Figure illustrates the basic plumbing requirements for a boiler installation utilizing Primary/Secondary piping when the boiler circulator will
not provide adequate flow for the system. Primary / Secondary is required to provide adequate flow for the secondary circuits.
WARNING
!
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.
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. Primary / Secondary Loop: All closely spaced tees shall be within 4 pipe diameters center to center spacing.
3. A minimum of 6 pipe diameters of straight pipe shall be installed upstream and downstream of all closely spaced tees.
4. The minimum pipe size of DHW piping should be ¾” diameter and CH piping should be 1” in diameter.
5. 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.
6. Piping shown is Primary/Secondary.
7. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
8.
VERY IMPORTANT
– Minimum flow rates outlined in this manual (2 gpm) must be maintained through the heat exchanger to minimize short
cycling.
9. 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.
10.
Unit is equipped with built-in primary pump.
This pump is sized to ensure proper flow rate through the boiler heat exchanger and related
piping.
11. IWH Applications - a mixing valve is recommended if the DHW temperature is set above 119
o
F.
150 / 199 Boiler Model Heating Only Installation
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
