Potterton Derwent Compact Plus Installation, Operation & Maintenance Manual page 22

SECTION 5
PAGE 20
Access to the main heat exchanger by removing the
perforated plate
Loosing the nuts for 2nd heat exchanger removal
Disconnect the water supply and return connection to
the secondary heat-exchanger.
Disconnect the fan, damper and duct by loosening the
nuts on the rear flange
Remove the whole assembly
With the flue brushes provided clean the flueways of
the cast iron heat exchanger if necessary.
Following completion remove the debris from the
bottom of the boiler.
Following completion of the above the boiler should
be reassembled. The integrity of the gaskets and
insulation should be checked and replaced if
necessary during re-assembly.
Clean the burner bars and ensure that the holes/slots
are clear. If necessary blow the slots and internals
clear with compressed air or soft brush and vacuum.
POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION AND MAINTENANCE MANUAL
DERWENT COMPACT PLUS - CONDENSING
On no account should the burners be wire brushed.
After re-assembly test for gas soundness as detailed
under Commissioning and check the burner manifold
union and pilot burner union for gas leaks.
Access to fan, pressure switches, dampers and
venturi.
Air Pressure Switches
Rear part of the secondary heat exchanger
Differential pressure connections connected to the air
pressure switches.