Technical information

This temperature sensor must be an NTC
with a resistance of 12 k
Ω
at 25 °C (see
also the list of accessories).
Strip approximately 5 mm of the insulation
from the connecting wires for the sensor.
Insert the stripped ends of the connecting
wires in the connections (3) and (4) of the
terminal block (Fig. 18). Ensure that the
wires do not cause a short circuit.
Tighten the screws firmly in the terminal
block.
20.3 Cylinder Thermostat
Temperature sensor for hot water cylinder
(if applicable)
DHW sensor (optional) available from
eco hometec.
This temperature sensor must be an NTC
with a resistance of 10 or 12 k
Ω
at 25 °C.
Alternatively a standard cylinder thermostat
may be used.
Strip approximately 5 mm of the insulation
from the connecting wires for the sensor.
Insert the stripped ends of the connecting
wires in the connections (5) and (6) of the
terminal block (Fig. 18). Ensure that the
wires do not cause a short circuit.
Tighten the screws firmly in the terminal
block.
20.4 Terminal block
When the connections have been made,
insert the terminal block (1) in the connector
(2) ( Fig. 19).
20.5 Laptop Serial Connection
For an extended diagnosis and display of
functions, a PC or laptop computer can be
connected to connector (3) (Fig. 19). The
required connecting cable and software is
available from eco hometec as an option.
21. Commissioning and Testing
21.1 Electrical Checks
A “Preliminary Electrical System Check”
should be carried out to ensure earth
continuity, short circuit, polarity and
resistance to earth using a suitable multi
meter.
21.2 Gas Supply
Check the gas installation and purge the
supply in accordance with current Gas
Safety Regulations.
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The gas valve fitted to the boiler is
not designed to withstand pressures in
excess of 60 mbar. When carrying out the
pressure test on the service pipe-work it is
essential that the gas cock fitted to the
boiler is in the closed position, failure to do
so will result in serious damage to the
boiler.
If using LPG, care should be taken to
ensure that the storage tank has been
correctly vented.
21.3 Connection to Pipe-work
The boiler is a low water content unit. When
connecting to an existing installation it is
important that old system deposits are
removed and are not allowed to
contaminate the appliance.
21.4 Water Treatment
In order to protect and prolong the working
life of the appliance, it is important the
general condition of older systems is
carefully considered.
The removal of debris, flux residue, grease,
metal swarf etc. from new systems and any
rust, black magnetic iron oxide sludge and
lime-scale from old systems is essential.
Consider high pressure flushing to remove
all debris in badly contaminated systems.

Fit in-line filters for full protection. All
installations should be treated and
maintained with Fernox MB1 at a
concentration of 4%.
21.5 Flushing System Pipe-work
Before the final flow and return connections
are made to the boiler, the system must be
thoroughly flushed.
Ensure that all radiator valves are open.
EC 25 Compact Installation/User Manual page
33