Atmos Energy HE26 - Manual (Page 49)

9.2.5 Burner/ spark ignition probe
Remove the front cover of the heat exchanger as described in § 9.1.2.
Unscrew the 4 screws shown on the photo to allow the stainless steel
burner mesh to be removed. These screws are Torx 20 (RVS A2 4,2x25”)
or Allen bolt M4x20 (units before 2006). The burner gasket should be
checked and replaced if damaged. Replace the burner mesh assembly
and refit the screws.
The spark ignition probe is shown in the photo in § 9.1.2 and also the
diagram in § 8.2. To replace the probe, pull off the ignition cable and
unscrew the 2 screws (Allen bolt M4x8). The seal should be checked and
replaced if damaged. Replace the probe and refit the seal and the screws.
Check the spark gap and replace the front cover, as described in § 9.1.2.
9.2.6 Flow/ return temperature sensors
The supply temp. sensor is located above the return temp. sensor. The
latter is shown in the photo. Disconnect the two pin connector and release
the spring clip. Pull out the sensor and replace.
Note: The replacement of the components below this box
requires the appliance to be drained:-
CH side – Drain the appliance using the drain tap and drain the
system at the lowest point.
After replacement, refill the appliance as given in § 6.1.
9.2.7 Pressure relief valve
Remove the plastic pipe from the safety discharge. Undo the pressure
sensor capillary and undo the union at the connection with the CH flow
pipe. Remove the pressure relief valve and inlet pipe. Remove the plastic
fitting from the discharge and undo the pipe connection to allow removal
of the valve. Fit replacement valve in reverse order using a sealant
suitable for potable water.
9.2.8 Pressure gauge sensor
Undo the pressure sensor capillary and unscrew the two posidrive screws
to release the cable clamp. Remove the gauge and capillary, and replace.
9.2.9 Pump head
Disconnect the pump wires from the controller (see note in § 9.2.1). Undo
two Allen bolts on the Wilo pump head (alternative pump Grundfos has 4
Allen bolts) to remove the pump head from the body. Fit replacement
pump head in reverse order. The pump must be vented via its vent plug
after refilling the appliance.
9.2.10 Expansion vessel
Unscrew the flexible hose connection, making sure that the sealing ring is
not damaged. Unclip the bracket holding the vessel and fit replacement
including the sealing ring. Using the Schroeder valve on the expansion
vessel, and pump if required, check the pressure is 1 bar.
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