The Boiler Components - REMEHA Avanta Range 24c Installation & Service Manual

1
2
3
4
5
6
7
8
9
fi g. 66 Components of the Remeha Avanta Plus
combi
112952.LT.GB.W7H.202
8.2

The boiler components

1. Automatic air vent
2. Flue / Air inlet connection
3. Flue gas measuring point
4. Heat exchanger
5. Front plate heat exchanger
6. Air inlet tube
7. Gas combination block
8. Two channel time clock (optional)
14
9. Control panel
10. Pressure gauge
11. Circulation pump
12. Expansion vessel
13
13. Ignition/ionization electrode
14. Stand off frame (optional)
12
8.3 Working principle
The Remeha Avanta Plus casing serves as a sealed air box,
with air drawn in by the fan. On the outlet side of the fan is
a venturi, into which a measured quantity of gas is injected
11
based on the volume of air available. The fan speed con-
trol is dependent on the settings of the external control, the
advanced boiler controller 'abc
10
tures (measured by the temperature sensors).
This method of gas/air ratio control ensures that the gas
quantity is precisely adjusted to the air quantity. Thus creating
optimum combustion over the whole heat input range. The gas
and air is mixed in the venturi and then passes into the spe-
cially designed pre-mix burner. After combustion, the hot flue
gas is directed through a specially designed, high efficiency
helicoil stainless steel heat exchanger with a large surface
area, and transfers it's heat to the system water circulating
around the coils. In the condensing part of the exchanger the
water vapour in the flue gas condenses within it and the heat
released during this process (the so-called latent or condens-
ing heat) is also transferred to the system water. The conden-
sate water so formed is discharged from the heat exchanger
via a siphon.

In normal operation, the boiler's flue gas discharge will pro-
duce a visible white condensing "plume" and therefore care
should be taken when choosing a location for the terminal.
Combi boiler operation
The Remeha Avanta Plus 24c, 28c, 35c and 39c are combi-
nation boilers with an integral plate heat exchanger provid-
ing instant domestic hot water. On opening a hot water tap,
detected by a flow sensor, which is located on the cold water
inlet side of the heat exchanger detects the demand. This
sensor then activates the motorised three-way valve to divert
primary flow to the plate heat exchanger which raises the
temperature of the cold water supply by a minimum of 35°C
to provide domestic hot water. Once the demand for hot water
stops the motorised valve automatically returns to the DHW
63
' and the prevailing tempera-
®