Buderus 500 - 24/C, Servicing Manual

Page: 25 / 80

Diagnosis 6
We reserve the right to make technical modifications Buderus Ltd. • http://www.buderus-domestic.co.uk
Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006 25
step 2
Check to ensure that the preset room temperature or heating configuration of the Buderus controls or ON/
OFF controller has been adjusted to a high enough setting (see operating instructions).
step 3
Is the preset room temperature or heating configuration of the Buderus controls or ON/OFF controller
adjusted to a high enough setting? Yes:
→
step
5
No:
→
step
4
step 4
Adjust the preset room temperature controller or heating configuration of the Buderus controls or
ON/OFF controller to a higher setting (see operating instructions).
→
box
42
step 5
Check to see if the “heating requirement” (
K
) indicator lights up on the display, see box 11.
step 6
Does the “heating requirement” (
K
) indicator light up? Yes:
→
step
11
No:
→
step
7
step 7
Check the Buderus controls or ON/OFF controller as per box 177.
step 8
Is the Buderus controls or ON/OFF controller working correctly? Yes:
→
step
9
No:
→
step
10
step 9
Replace the thermostat cable.
→
box
42
step 10
Replace the Buderus controls or ON/OFF controller.
→
box
42
step 11
Check to ensure that the CH flow temperature at the DBA control panel or on the Buderus controls or ON/
OFF controller is adjusted to a high enough setting as per box 14 and box 61 .
step 12
Is the CH flow temperature adjusted to a high enough setting? Yes:
→
step
13
No:
→
step
15
step 13
Are enough thermostatic valves open on the radiators, convectors, etc? Yes:
→
step
16
No:
→
step
14
step 14
Open more thermostatic valves on the radiators, convectors, etc.
→
box
42
step 15
Adjust the CH flow temperature as per box 14 and box 61. Ensure that the Buderus controls or
ON/OFF controller are calling for a heating demand.
→
box
42
step 16
Check to ensure that the CH flow temperature is correctly adjusted, see box 14.
step 17
Is the CH flow temperature adjusted to a high enough setting? Yes:
→
step
19
No:
→
step
18
step 18
Adjust the CH flow temperature to a higher setting, see box 14.
→
box
42
step 19
Is the CH flow temperature of the boiler sufficient to heat the building? Yes:
→
step
21
No:
→
step
20
step 20
Install a larger boiler.
→
box
42
step 21
Is there a hot water supply? Yes:
→
step
22
No:
→
box
41
step 22
Is an
internal
3-way valve fitted? Yes:
→
step
23
No:
→
step
34
step 23
Check the movement of the servomotor of the
internal
3-way valve, see box 181.
step 24
Does the servomotor of the
internal
3-way valve move correctly? Yes:
→
step
25
No:
→
step
28
step 25
Check the drive mechanism of the
internal
3-way valve, see box 195.
step 26
Is the drive mechanism working correctly? Yes:
→
box
42
No:
→
step
27
step 27
Replace the drive mechanism of the
internal
3-way valve, see box 198.
→
box
42
step 28
Check the actuation of the servomotor of the
internal
3-way valve, see box 185.
step 29
Does the servomotor of the
internal
3-way valve start up correctly? Yes:
→
step
30
No:
→
step
31
box 23