Eco Hometec EC 25 COMPACT Technical Manual - page 7
digital controller that automatically adjusts
the boilers output depending on system
load requirements.
This feature, Variable Controlled Output
(V.C.O.), is the very latest from eco
hometec in condensing technology and
ensures the boiler maintains optimum
efficiencies even when operating at part
load.
A key component of VCO is the ECONOX
premixing, radiant, gas burner.
A unique feature of the ECONOX burner is
its radiation cylinder that has been specially
designed to suit the geometry of the
combustion chamber. It is composed of a
perforated sheet of stainless steel. On the
surface of this burner, accurate quantities of
premixed gas and air are burnt almost
without a visible flame
The eco hometec on-board computerised
VCO system with integral fault diagnostic
facility ensures that optimum efficiency is
maintained when operating in both heating
and domestic hot water modes.
According to the required flow temperature,
the premixing burner modulates constantly.
To save electricity, a 310Volt DC, high
efficiency fan is used with a variable speed
and power capacity; if the heat demand
decreases, the fan will turn at a lower
speed, which results in a lower power
consumption.
The air fan is programmed to supply given
amounts of air for specific burner outputs.
This air pressure then controls the gas
valve, which in turn matches the gas
pressure to the required gas to air ratio
(1:1).
The combustion gases are then passed
through the stainless steel heat exchanger
to the atmosphere. During their passage
these hot gases are used to preheat both
the return water to the boiler and the
incoming combustion air thus ensuring that
all of the available energy is used as
efficiently as possible.
3.2
Approvals
The unit has been approved according to
the European standards (CE).
3.3
Modulating pump
A modulating integral circulating pump is
supplied, which operates at to different
speeds and results in lower power
consumption.
This feature is to help maintain a
temperature difference of 20
O
C between the
flow and return temperatures on systems
using radiators.
IMPORTANT. Without VCO (Variable
Controlled Output) or an alternative control
over the temperature of the return water, the
performance of a condensing boiler will be
impaired and significantly lower.
A modulating pump is essential in all
condensing systems if system
differentials are to be maintained.
3.4
Frost Protection
If the flow temperature falls below 8
0
C, in
order to provide frost protection, the pump
will run even though there may be no
demand for heat. If the temperature
continues to fall, at 5
0
C, the burner will also
ignite. At 10
0
C the appliance will return to
standby mode.
3.5
Year Long Protection
During summer months, the pump and
mixer valve (if fitted) are exercised daily.
This prevents seizure of internal
components thus reducing maintenance
costs.
3.6
P.P.S Plastic Flue System.
Due to the extremely low temperature flue
gases, the boiler may be flued using the
lightweight and corrosion resistant eco
hometec P.P.S. plastic flue system. The
boiler can be flued over distances
previously impossible (up to 100 metres
depending on output and flue design) from
conventional boilers.
EC 25 Compact Technical Manual page
7