Alde Compact 3030 Gebrauchsanweisung Seite 47

8.4 Bleeding of the heating system
When filling glycol mixture into the system, air pockets may form, depending on how the piping system
is installed. A sign of air in the system is that only the first few metres of the pipes extending from the
boiler heat up, even though the circulation pump is running.
In the case of a newly filled heating system, small air bubbles may form in the expansion vessel resulting
in rippling noise. If the circulation pump is stopped for a few seconds, the bubbles usually disappear.
If the problem persists, bleed the heating system.
WARNING Scalding hazard
Remember: the glycol mixture can be very hot.
NOTICE
Never open the air screws while the pump is running, as this would draw air into the system.
Vent as follows
1. Boiler must be switched off.
2. If the boiler is equipped with a vent screw on the output pipe: open the screw and leave it open until
fluid comes out. Proceed to item 4.
3. If the boiler is fitted with automatic vents, venting will be performed automatically. Start the boiler
and let the fluid circulate in the system until it is vented. Top up with fluid if necessary in accordance
with item 5. If this does not help, turn off the boiler and go to item 4.
4. Open the other bleed screws in the system one by one. Leave them open until glycol mixture comes
out of them, then close them.
5. Check the fluid level in the expansion vessel. Top up if the level has dropped after ventilation. The fluid
level in the expansion tank must lie 1 cm above the min. line (Fig. 19) when the system is cold.
6. Start the boiler and allow to run for a while. Feel whether the pipes and convectors around the vehi-
cle are getting warm. If they are hot, venting is complete, otherwise proceed to point 7.
7. Put the pump (pumps in a dual-zone system), in speed position 5. Turn off electricity and gas.
Set the heat to 30 °C and let the boiler run for 5 minutes. Next ,begin again at item 1.
Measures for residual air bubbles, single axle caravan
NOTICE
Overheating
• Check that the system is properly ventilated.
• Never use full electricity or gas capacity until the system is properly ventilated.
1. Stop the circulation pump.
2. Lower the front of the caravan as far as possible. Let it stand for a few minutes, so that the air can
move upwards in the heating system.
3. Open the air screw at the highest point. Leave it open until glycol mixture runs out.
4. Raise the front of the caravan as far as possible and repeat steps 3.
5. Place the caravan in a horizontal position and start the circulation pump.
6. Check that the pipes and convectors around the vehicle are heating up.
Measures for residual air bubbles, bogie trailers and motorhomes
It is easiest to air the heating system with the vehicle on a sloping surface, or with one end of the
vehicle suspended by a jack. Air the heating system on a slope as described for the single-axle
caravan above. Alternatively, the heating system can be aerated with a filling pump at a workshop;
contact Alde Service Partner.
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