Potterton LPG 50e Installation And Servicing Manual page 19

COMMISSIONING - Page 19
FIG. 26
Shut down the boiler remove the pressure gauge and refit
the screw in the test nipple ensuring that a tight seal is
made.
Refit the controls cover.
Relight the boiler and heat the system to maximum. Check
for water leaks, turn the boiler off, drain the system whilst
hot.
Refill the system and on sealed systems adjust to the
correct cold fill pressure. Set the pressure gauge pointer to
the system design pressure.
If a by-pass circuit is fitted the by-pass valve should be
adjusted with the boiler operating under minimum load
conditions to maintain sufficient water flow through the
boiler to ensure that the overheat thermostat does not
operate under normal operating conditions.
Pilot Burner
The pilot is pre-set and no adjustment is required. The pilot
flame envelope should cover the electrode tip, see FIG. 30.
If the pilot flame is not as illustrated, remove and clean the
pilot as described in the Servicing Instructions Section 3,
PILOT BURNER, Page 22.
Boiler Thermostat
At its minimum and maximum settings, the thermostat
should control the water flow temperature at approximately
0 0 0
55 C—82 C (1 30 F— 1 80
The thermostat has been calibrated by the makers and no
attempt should be made to re-calibrate it on site. Turn the
thermostat to the '0' position and check that the main burner
shuts down.
Gravity Hot Water/Pump Over-Run Thermostat
The function of this thermostat is determined by the position
in which the GRAVITY/FULLY PUMPED SYSTEM selection
switch is set. The thermostat is pre-set and no adjustment is
possible.
0
F).
On the FULLY PUMPED switch position it will operate as a
pump over-run thermostat and will keep the pump running
after the boiler has shut down, as long as the water
temperature within the boiler is above approximately 80
On the GRAVITY switch position it will operate in series with
the boiler thermostat when only the gravity domestic hot
water circuit is in operation.
It will over-ride the boiler thermostat when the water
temperature within the boiler is above 80
Overheat Thermostat
The overheat thermostat is pre-set and no adjustment is
possible. It will require manually resetting if an overheat
condition occurs. Access to the reset button is through a hole
in the underside of the controls cover, see
FIG. 2.
Other Boiler Controls
All boiler mounted controls are designed so that if any fault
should occur they will fail safe. No further setting or checking
is necessary.
External Controls
Check that any other external control connected in the
system, such as clocks and thermostats, control the boiler as
required.
User's Instructions
A User's Instructions leaflet is provided with this boiler but
the householder must have the operation of the boiler and
system explained by the Installer. The householder must
also be advised of the importance of annual servicing and of
the precautions necessary to prevent damage to the system
and building, in the event of the system remaining out of
commission in frost conditions.
0
C.
0
C.