Old Brivis Central Heater not working (Buffalo Series)

[darkage]

Greetings all,

I have an Old Brivis Central Heating unit from the 80's. It looks like a Buffalo Series style.

Pilot light is still on and strong but when turning it on from the Thermostat I do hear a faint clicking as if a relay is activated on the outdoor unit but no flame.

On the theromostat normally it arcs a very small amount when switching on which its not happening this time around.

Confirmed power is going to unit and manual fan can switch on the blower. Just when turning it on at the thermostat dont get main burner.

Any ideas on approach for repair ? Have taken off indoor thermostat cover and cleaned the contact points that didnt work.