LP-719 Rev. 000 Rel. 000 Date 6.25.20
28
In mixed temperature applications, a mixing valve is required for the protection of low temperature loops.
Figure 19 - ELUWCN with Multiple Central Heating Circulators
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.
NOTICE
Figure illustrates the basic plumbing requirements for a combi 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. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
7.
VERY IMPORTANT
– Minimum flow rates outlined in this manual (2 gpm) must be maintained through the heat exchanger to minimize
short cycling.
8. 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.
9.
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.
Primary/Secondary Piping Shown - See
Note 2
