LAARS Rheos+ RHHV - Install and Operating Manual - Manual (Page 18)

Rheos+ Boiler and Water Heater Page 17
If the water at the inlet of the copper heat
exchanger is less than 140°F (60°C), water from the
outlet of the copper heat exchanger will be directed
back to the inlet of the copper heat exchanger, and will
mix to bring the inlet water up to 140°F (60°C). Once
through the copper heat exchanger, the water picks up
another 20-25°F (11-14°C) (when at high fire), and
it leaves the boiler at 160-165°F (71-74°C). This hot
water is then sent to the system.
If the water at the inlet of the copper heat
exchanger is 140°F (60°C), or higher, the water will be
allowed to flow through the copper heat exchanger and
directly to the outlet of the Rheos+, and there will be a
20-25°F (11-14°C) temperature rise between the inlet
and outlet of the unit, when the unit is at high fire.
The pump in the heater is sized for the heater’s
heat exchangers, the internal mixing system, and 30
feet of full-sized piping, with a normal number of
fittings taken into consideration.
The minimum inlet water temperature for the
Rheos+ is 50°F (10°C) to avoid condensing on the
copper coils.
Figure 5 - Hydronic Piping — Multiple Boilers (Alternate)
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