Mike the Boilerman 

Your independent Potterton 

Netaheat specialist covering Berkshire, Wiltshire & surrounding counties

For more information or to book your breakdown repair, call or text me on 

07866 766364 

Ignition sequences:

I’m getting a steady trickle of questions about the ignition sequence of the various versions of Netaheat, from people investgsting why their own boiler is not working. I’ve written these out in a bit of a hurry so there may be details slightly wrong but the broad picture is correct.

Netaheat MkI (Netaheat Original):

230Vac call for heat arrives on SwL terminal

Control thermostat calls for heat

Fan starts

APS detects fan running

230Vac sent to ignition module

Ignition module delivers stream of sparks to pilot burner

230Vac opens solenoid gas valve

Pilot flame ignites

Ignition module detects pilot flame and stops spark

Mercury vapour gas valve sensor warms up

Mercury vapour gas valve opens

Gas sent to main burner

Main burner ignites

Boiler runs until thermostat is satisfied

Netaheat MkII and MkIIF:

230Vac call for heat arrives on SwL terminal

Control thermostat calls for heat

Fan starts

APS detects fan running

230Vac sent to ignition module

Ignition module delivers stream of sparks to pilot burner

230Vac opens gas valve pilot solenoid

Pilot flame ignites

Ignition module detects pilot flame and stops spark

Mercury vapour switch sensor warms up

Mercury vapour switch operates and energises gas valve main burner solenoid with 230Vac

Main burner ignites

Boiler runs until thermostat is satisfied

Netaheat Electronic:

230Vac call for heat arrives on SwL terminal

Control thermostat calls for heat

PCB checks no pilot flame is present

Fan starts

APS detects fan running

PCB delivers stream of sparks to pilot burner

PCB opens gas valve pilot solenoid with 230Vac

Pilot flame ignites

PCB detects pilot flame and stops spark

PCB energises gas valve main solenoid with 230Vac

Main burner ignites

Boiler runs until thermostat is satisfied

Netaheat Profile (and Potterton Profile):

230Vac call for heat arrives on SwL terminal

Control thermostat calls for heat

PCB checks overheat thermostat is not tripped

PCB checks no pilot flame is present

Fan starts

APS detects fan running

PCB opens gas valve pilot solenoid with 230Vac

Pilot flame ignites

PCB detects pilot flame and stops spark

PCB energises gas valve main solenoid with 230Vac

Main burner ignites

Boiler runs until thermostat is satisfied