Commissioning; Header Tank Installations; Pressurised Expansion Vessel Installations; Priming The Fuel System - Webasto thermotop C Installation Instructions Manual

COMMISSIONING

Upon completion of the installation, check the
integrity of all joints. Fill the heating system with
75/25 water/antifreeze mixture through the fill point.
Bleed as much air as possible from the system and
the radiators before commencing the start up proce-
dure.

Header Tank Installations

Check all electrical connections. Turn the isolation
switch to the 'ON' position.
Switch the heater on at the operating switch. The
heater will commence it's start up procedure.
Several start attempts may be required in order to
bleed enough fuel through to the heater to enable
start up. Satisfactory operation will only be
achieved once all air bubbles have cleared from the
fuel lines.
Once the heater is running, air will bleed out of the
water system, and the header tank will require
constant refilling to the max mark It may be
necessary to bleed the radiators. Bring the heater
up to full temperature and check that all air locks
are bled from the heating system. Switch off the
heater and allow to cool (overnight if possible), and
check the water level and top-up as required.
Pressurised Expansion Vessel
Installations
Pre fill the heating water system as detailed above
but with 75% water / 25% antifreeze. With this sys-
tem it may be necessary to fill the radiators with a
filling tool or make up a pipe and inject the coolant
through a radiator bleed vent. Because this system
needs to be pressurised the remainder of filling will
need to be done with the filling loop. Open both ball
valves on the filling loop and commence filling until
the pressure gauge reads 1bar (14.5psi).
It will be necessary to fill the system up and bleed
all the radiators and recharge again. This process
will have to be repeated a number of times.
Check all electrical connections. Turn the isolation
switch to the 'ON' position.
Switch the heater on at the operating switch. The
heater will commence it's start up procedure.
Several start attempts may be required in order to
bleed enough fuel through to the heater to enable
start up. Satisfactory operation will only be
achieved once all air bubbles have cleared from the
fuel lines.
Webasto Part Number : 4110310A
Issue No: 02 : 10th November 2010
Matthew Millard
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In the interests of continued development, we reserve the right to change
specifications without prior notice
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Switch on the heater, make sure the pressure gauge
does not drop below approximately 0.5 bar / 7psi.
After a few minutes of running vent the radiators again
and recharge the system with the filling loop to 1bar /
14.5psi.
Be aware that the pressure may drop during this period
due to the AAV's (Auto Air Vents) if fitted. When all the
air is out of the system and the pressure is at 1bar /
14.5psi turn off both of the ball valves on the filling loop.
Switch off the heater and allow to cool.
When cold, check the 'cold water pressure' and
recharge to 1bar / 14.5psi if required.
Turn off the ball valves on the filling loop.
If the system is over charged by mistake the excess
pressure can be removed by either bleeding the
radiators or turning the knob on the pressure relief
valve.
Note when the system is operating the pressure will
increase by approximately 25% of the cold pressure.

Priming the fuel system

To prime a dry fuel system the heater needs to be
switched ON and the heater will go through its start up
procedure. During this time the air fan & the water
pump will start. The fuel pump will begin dosing after a
few moments. Fuel pump operation is characterised by
a 'ticking' sound from the fuel pump. You will find that
this can be a lengthy process and the heater will go
through a number of start and shut down cycles until
the fuel finally gets to the heater. For information the
fuel dosing pump dispenses 0.063ml of fuel every 'tick'.
Depending on the pipe lengths & the number of start
attempts you may find the heater 'locks-out', to recover
from a 'lock-out' situation remove the main fuse from
the wiring harness and replace it after 30 seconds and
the heater will be reset.
Tip: When priming the system remove the fuel pipe from the heater
fuel inlet stub during priming. Be sure to catch the fuel in a suitable
container. When a steady fuel flow occurs from the pipe, refit the pipe
back to the heater inlet.
If the Webasto fuel filter kit is fitted, (4110766A) make
sure the fuel tap is fully open, (fully anti-clockwise).
Marine Comfort
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