Supplied By www.heating spares.co Tel. 0161 620 6677
19
221481C
11 Fault Finding
Remedy
11.3 Thermostat Will Not Cut Out
Thermostat phial not fitted in pocket.
Faulty thermostat.
11.2 Main Burner Will Not Light
External, remote controls not “On.”
Boiler thermostat not on.
Check that any remote controls are calling for heat.
Check boiler thermostat is in an “On” position, see
also Section 11.9.
Fit phial in pocket.
Replace thermostat.
11.1 Pilot Goes Out after a Period of
Remaining Alight
Front cover not correctly fitted.
Flue parts not fitted or sealed properly.
Electrical supply failure causing over heat cutoff to
operate.
Operating cut-off operating.
Pump incorrectly wired.
Fault and Cause
11.6 Appliance Noisy in Operation*
Overgassed.
Complete lack of water.
Air in system.
Water flow rate.
Check burner pressure against data label and adjust
only if more than 10% away from stated required
figure.
Check system controls for correct installation or
correct type of controls.
Remove air from system. When system is first
commissioned the air dissolved may take some time
to boil out, therefore attempts should be made to
vent air during the first weeks of the installation.
Check venting of system, as air bubbles can remain
suspended in the water if system is not well vented.
Check that flow rate is correct. Check that pump is
correct size and is correctly adjusted. Bypass not
fitted or set correctly.
Fit parts correctly.
Seal cavity or fit flue parts correctly as described in
installation instructions.
Relight pilot.
Refer to Section11.3.
Connect pump in accordance with diagram 7.2.
11.4 Overheat Cutoff Cuts Out Prematurely
Air in heating body.
Water circulation low or stopped.
Overheat cutoff operates before boiler cycles on
maximum boiler thermostat setting.
The correctly set overheat cutoff operates
prematurely. There is no air in the heating body
and water circulation satisfactory.
Vent system. Alter system layout if necessary.
Pump not functioning correctly. Check pump is wire
directly to the boiler. Alter system if necessary.
Change faulty overheat cutoff.
Change faulty heating body.
Increase setting.
Increase gas pressure.
Check burner pressure against data label. Reset only
if more than 10% away from required figure.
* There remains on most boilers a residual noise more noticeable at high temperatures. Normal operation of
the boiler over a period should remove most noise.
11.5 Insufficient Heat
Thermostat set too low.
Inlet gas pressure inadequate.
Governor setting incorrect.
(ensure thermostat is on maximum setting).