Buderus 500 - 28/C Servicing Manual page 62

7 Actions
box 207
3 3
1 2
A
Remove all pipes beneath the boiler.
CAUTION!
Note that water will squirt out when the internal 3-way
valve is removed. Have a bucket and a supply of dry
cloths to hand.
Loosen the gas pipe at the gas valve.
Remove the two screws (item 1).
Remove the complete hydraulic assembly.
Remove the four M8 nuts (item 2).
Remove the five screws (item 3).
Remove the plastic block (H3).
box 208
1
2
Loosen the screw in the plastic block (item 2).
Remove the pressure relief valve (item 1), see box 276
or 277.
Remove the drive mechanism on the internal 3-way valve,
A
see box 200.
CAUTION!
Note that water will squirt out when the internal 3-way
valve is removed. Have a bucket and a supply of dry
cloths to hand.
We reserve the right to make technical modifications
62
H3 3
2 2
Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006
box 209
1
Replace the housing of the 3-way valve.
box 210
Refit all components, following the above procedure in
reverse order.
Fill the heating system, vent it of air and place the boiler
into operation, see box 52 to 58.
box 211 Check the Buderus 24V AC external
3-way valve – movement of the servomotor
Put the boiler into operation, see box 54 and 55.
Adjust the hot water in the "Settings" menu on the DBA
control panel of the boiler to 60 °C, see box 61.
Open a hot water tap.
Check to see if the servomotor of the Buderus
24V AC external 3-way valve, during the operating
code C [0c] rotates from the setting for heating mode
(position "1") to the position for hot water mode
(position "2").
Close the hot water tap.
Check to see if the servomotor runs back again.
Adjust the hot water in the "Settings" menu on the DBA
control panel of the boiler, see box 61.
Buderus Ltd. • http://www.buderus-domestic.co.uk