Underfloor Heating System - Wolf CGB-11 Installation Instructions Manual

Underfloor heating system

When using pipes which are impermeable to oxygen, the un-
derfloor heating system can be directly connected to a heating
system with a rated output of up to 13 kW, subject to system
pressure drop.
Generally install a thermostat for underfloor heating systems,
to protect the pipes from overheating.
When connecting underfloor heating systems with a demand
higher than approx. 13 kW, an additional three-way mixer plus
an additional pump will be required.
Install a regulating valve in the return, which can reduce the
excessive head of the additional pump, if required.
Regulating valves must not be able to be adjusted
NB
by the system user.
Provide system separation by means of a heat
exchanger, when using pipes which are not imper-
meable to oxygen. Inhibitors are not permissible.
If an additional heating circuit is operated in parallel to the
underfloor heating system, match that circuit hydraulically to
that of the underfloor heating system.
When you operate a gas fired boiler together with
NB
an underfloor heating system, we recommend
you size the available volume of the diaphragm
expansion vessel 20 % greater than recommended
by the relevant standard. A diaphragm expansion
vessel which is too small will result in an ingress of
oxygen into the heating system and therefore lead
to corrosion damage.
68
Design information
Fig.: Underfloor heating system
Operation of the gas fired condensing centre with a DHW
circulation line:
We recommend proper insulation of the pipework where the
gas fired condensing centre is connected to a DHW circulation
line. In addition, equip the DHW circulation line with a time
switch. This is commonly started for DHW operation during
times of demand. We recommend the following procedure for
the optimum, energy-efficient adjustment of the time switch:
Never set the time switch permanently ON during times of
demand, but ON and OFF in 15 minute intervals. The slight
cooling down of the heated water inside the DHW circulation
line will not result in any loss of convenience.
Your DHW circulation pump will then be adjusted so that
energy consumption is minimised yet DHW convenience is
maximised. This enables the DHW circulation pump ON-time
to be reduced by 50 %.
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