Commissioning - Buderus 500-24S Installation And Maintenance Instructions Manual

2

Commissioning

2 Commissioning
When a boiler starts up there are a couple of things that
happen. Below is a short process description:
When there is a heat demand:
The fan starts up and the glow ignitor turns on.
When there is a DHW request then the three-way-valve
switches from CH operation to DHW operation.
The pump starts up as soon as the three-way-valve is in
the right position.
Once all the requirements are met (glow ignitor is hot
enough, fan is operating at the correct speed and the
pump is on) then the gas valve will open.
A flame may or may not develop, but regardless of that
fact, the glow ignitor extinguishes. The operating controls
are released once a flame is sensed. After a possible
check, the boiler will deliver the requested output.
Should the flow check fail, the boiler will shut down for a
short while and then try to start up again.
If no flame develops then the gas valve closes and the fan
continues to run for a while to purge the appliance. The
boiler will try to start up three times. If no flame develops
after three attempts the boiler will lock-out.
When the heat demand stops:
The gas valve closes.
The fan will run for a short time to purge the appliance.
The pump will continue to run for a short time to disperse
any remaining heat energy from the boiler into the heating
system.
If there has been a heat request, then the three-way-valve
will switch back to the central heating setting.
Follow the steps described in this chapter to properly
commission the boiler and fill out the commissioning log
book.
NOTE
If a fault occurs, then refer to the servicing
manual or contact Buderus.
32 Buderus 500-24S - Subject to modifications resulting from technical improvements