Service manual

4
Check the heating system’s uid level regularly in the
expansion vessel. The level should be approximately 10
mm above the ”min” mark when the system is cold. The
heating system should be lled with a mixture of water
and glycol. For preference, use high quality pre-mixed
glycol (with inhibitor) intended for use in aluminium heating
systems. If using concentrated glycol, the mixture should
consist of 60% water and 40% glycol. If the heating system
will be exposed to temperatures below –25°C, the glycol
content must be increased, but not to more than 50%.
Any vessels used in handling the liquid must be spotlessly
clean, and the pipes in the heating system must be free of
contamination. This will prevent the growth of bacteria in
the system. The glycol mixture should be changed every
second year, since its ability to protect against corrosion,
for example, will deteriorate.
The glycol content should be checked before topping up
with new liquid. This will ensure that the concentration of
glycol in the mixture is not too high.
If the uid level in the expansion tank falls for reasons other
than evaporation, check all joints, drain cocks and bleeder
screws to ensure that they are not leaking. If the glycol-
water mixture leaks out, rinse with water and wipe up.
Never allow the heating system to stand empty of glycol
uid.
Adding liquid:
Ensure that the vehicle is standing level, and check that
the bleeder screws and drain cocks are closed. Release
the plastic nut on the circulation pump, located on the
expansion vessel, and lift out the pump. Pour the glycol
mixture slowly into the expansion vessel, using a watering
can. When the system is being lled, air-pockets may form,
depending on how the pipe-system has been installed.
A good indication that there is air in the system is when
the heat only travels a few metres along the pipe from
the boiler, despite the fact that the circulation pump is
operating.
To make relling and bleeding easier, we recommend using
the Alde lling pump which quickly both lls and bleeds the
system automatically.
Bleeding a caravan heating system (manually):
The LPG boiler must be switched on and the circulation
pump switched off. Start by opening the bleeder screws
(please refer to the vehicle instruction book for their
location). Leave them open until liquid escapes through the
spout at the air screw. Switch on the circulation pump and
let it run for a while. Check whether the pipes and radiators
all around the caravan are warm.
If air still remains in the system, try the following:
The LPG must be switched on and the circulation pump
switched off. Lower the front of the caravan as far as
possible using the jockey wheel. Leave it in this position for
several minutes, to allow any air to rise to the highest point
in the system. Open the bleeder screw at the highest point
and keep it open until all the air has escaped. Raise the
front of the caravan as high as possible using the jockey
wheel, and repeat the process. Return the caravan to a
horizontal position and start the circulation pump. Check
that the heat is circulating all around the caravan.
When bleeding a bogey wagon or a motor caravan, it is
easier to park on a steep slope, or raise the vehicle using a
jack.
Filling pump
Art. no. 1900 811
1:1 MAINTAINING THE HEATING SYSTEM