Bailey Approach Advance - Heat Transfer Fluid

the open position until the next time the hot
water cylinder is used.
NB: Check that the red breather valve (Fig.1
[N]) is allowing air to enter the hot water
cylinder, when it is being drained, and that the
clear plastic hose is not obstructed.
ClosedOpen
N
Fig.1
Heat Transfer Fluid
The central heating system is lled with
heat transfer uid (HTF), a solution of 50%
ethylene glycol antifreeze and 50% water.
!
The boiler must not be switched on if
there is no HTF in the system.
The antifreeze manufacturer will
have a maximum water hardness
recommendation. Read the product
label or contact the product
manufacturer for details.
using the Alde service pump. Any containers
used for handling or storing the HTF should
be checked rst, and must be visibly clean
to avoid introducing contaminants or foreign
objects into the system.
Alde recommends using the Alde 1900-811
or 839 twin-motor service pump to ll the
system.
To ll the system by hand, unscrew the
expansion tank cap (Fig.2 [R]), and lift the
circulation pump (Fig.2 [S]) out of the tank (if
applicable). Carefully pour the HTF into the
tank, and repeat until the uid level is about 1
cm above the MIN mark when cold.
Alde recommends antifreeze meeting VAG
G12++ or G13 specication, and deionised
water (0 ppm).
50:50 ethylene glycol antifreeze and water
will protect against frost down to -35 to 37°C.
A refractometer and/or hydrometer can be
used to measure the strength of the antifreeze
solution.
Corrosion protection will vary depending on
the lifespan of the antifreeze. Read the product
label or contact the product manufacturer for
details.
!
Always replace the HTF in accordance
with the antifreeze product’s lifespan.
If in any doubt, replace the HTF after
2 years.
The corrosion inhibitors found in ethylene
glycol antifreeze may not be cross-compatible.
When topping up or replacing the HTF, ensure
the new antifreeze is compatible with the
current antifreeze product. Read the product
label or contact the product manufacturer for
details.
i
As a rough guideline, blue and red
antifreeze products are not
compatible with each other, but VAG
G12++ and G13 spec antifreeze (purple/
magenta) is compatible with both.
Failure to ll with suitable HTF may
result in severe damage to your Alde system,
which is not covered under warranty.
Filling
The central heating system is lled with HTF
through the expansion tank, either by hand, or
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FITTED EQUIPMENT- The Alde Heating System
FITTED EQUIPMENT- The Alde Heating System