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6.3 Selection of control mode
Systems with specified control mode:
If the control mode (proportional or constant pres-
sure) and the pump head have been specified for the
system in which the pump is to be installed, the
pump should be set as specified. See section
7. Setting the pump. If problems should arise, see
section 8. Fault finding chart.
Systems with no specified control mode:
If the control mode and the pump head have not
been specified for the system, (for instance, an
uncontrolled standard pump is replaced by the
UPED pump), it is advisable to use the settings in
the following table and in section 6.3.1 Setting in
connection with pump replacement.
In systems
with ...
for instance ...
select this con-
trol mode ...
relatively great
head losses in
the boiler circuit
and the distribu-
tion pipes
1. Two-pipe
heating sys-
tems with
thermostatic
valves and
with:
• a dimensioned pump head higher than 4 metres,
Proportional
pressure
• very long distribution pipes,
• strongly throttled pipe balancing valves,
• differential pressure regulators,
• great head losses in those parts of the system
through with the total quantity of water flows (e.g.
boiler, heat exchanger and distribution pipe up to
the first branching) or
• low differential temperature.
2. Underfloor heating systems and one-pipe heating systems with
thermostatic valves and great head losses in the boiler circuit.
3. Primary circuit pumps in systems with great head losses in
the primary circuit.
relatively small
head losses in
the boiler circuit
and the distribu-
tion pipes
1. Two-pipe
heating sys-
tems with
thermostatic
valves and:
• with a dimensioned pump head lower than
2metres,
Constant
pressure
• dimensioned for natural circulation,
• with small head losses in those parts of the system
through with the total quantity of water flows
(e.g. boiler, heat exchanger and distribution pipe up
to the first branching) or
• modified to a high differential temperature
(e.g. district heating).
2. Underfloor heating systems with thermostatic valves.
3. One-pipe heating systems with thermostatic valves or pipe balanc-
ing valves.
4. Primary circuit pumps in systems with small head losses in the pri-
mary circuit.
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