Bmk5000 - 6000 Supply And Return Piping; Dual Inlet Return Piping - Watts AERCO Benchmark BMK750 Installation And Start-Up Manual

Benchmark Platinum-Edge [ii]: Installation Manual
SECTION 2 – INSTALLATION
2.6.3 BMK5000 – 6000 Supply and Return Piping
Benchmark 5000 and 6000 Platinum boilers utilizes 6" (15.24 cm) flanged fittings for the water
system supply and return piping connections. The physical location of the supply and return
piping connections are shown in Figure 2-4c.
1-1/2" PROPANE GAS INLET
(DUEL FUEL & PROPANE
ONLY)
Figure 2-4c: BMK5000 & 6000 Supply and Return Locations (DF Model Shown)

2.6.4 Dual Inlet Return Piping

The standard dual inlet connections allow Benchmark Platinum units to be configured with a
separate cooler return temperature zone, rather than blending high and low return temperature
zones. Utilizing the dual return capability, these boilers can take further advantage of the
condensing capabilities. When configured with a lower return temperature zone or AERCO
SmartPlate, thermal efficiency can improve by up to 6% (based on an 80 °F (26.7 °C) minimum
return water temperature at full fire). Lower return temperatures are possible, which would yield
even greater efficiency gains. The maximum temperature differential across the boiler heat
exchanger is 100 °F (37.8 °C).
To use the secondary inlet, pipe the warmer return water to the secondary (upper) inlet and
the cooler return water to the primary (lower) inlet. If the flow through both the primary and the
secondary return is constant, then the combined minimum flows must equal the specified
minimum flow of the boiler. If the flow through either of the inlet returns is intermittent, then the
minimum flow through one of the return connections must always equal the specified minimum
flow of the boiler. Contact your AERCO representative for additional information.
• GF-210 •
OMM-136_G
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
8/20/2020
6" HOT WATER
OUTLET
(15.24 cm)
AIR INLET
14" (35.6 cm)
6" (15.24 cm)
SECONDARY
WATER INLET
6" (15.24 cm)
PRIMARY
WATER INLET
2" NATURAL
GAS INLET
CONDENSATE
DRAIN
Page 25 of 62