Low Loss Header (Llh) Utilization; To Utilize The Llh - Bosch KBR16-3 Installation And Service Instructions Manual

6.5

Low Loss Header (LLH) utilization

A Low Loss Header is primarily used on systems that require higher flow
rate (gpm) requirements that exceed the flow rate (gpm) of the low mass
heat exchanger. Typically systems that require additional zone pumps
that are external to the appliance or exceed the single zone limitation of
4.5 gpm would require the low loss header.
A Low Loss Header is used to achieve hydraulic separation between the
appliance and system piping.
If the heating system is a single zone and has no additional circulators
other than its integrated pump, no modification of the LLH manifold is
required.
If the heating system has additional circulators (for example multiple
zones of panel radiator or baseboard heat) then the LLH plunger must be
removed to allow the hydraulic separation of the appliance from the
system.
This allows the appliance to continue satisfying the demands of the
heating system when high system flow rates are expected.
2
1
Fig. 19
[1] Central heating supply
[2] Central heating return
[3] Domestic hot water outlet
[4] Domestic cold water inlet
[5] Low Loss Header
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6.5.1

To utilize the LLH

▶ Switch off and isolate the boiler
▶ Drain the boiler
▶ Remove front panel
▶ Locate the LLH at the left-hand side of the lower section of the boiler
1. Unscrew the cap [a] from the body of the LLH [c]
– This will break the label across the cap and body indicating that
the LLH has been employed
2. Withdraw the cap [a] and plunger assembly [b]
3. Unscrew the plunger assembly [b] from the cap [a],
4. Set the plunger assembly [b] aside
5. Re-fit the cap [a] without the plunger assembly [b]
6. Tighten the cap [a] and ensure it is secure.
a
b
2.
3.
4.
6.
1.
5.
Fig. 20 Utilizing the LLH
Installation | 33
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