|Primus 2490 Unofficial Repair Guide v1.pdf||Primus 2490 Unofficial Repair Guide
This is an unofficial picture based guide covering my own experience with repairing the Primus 2490 Central Heating System. The PCB Overlay picture (see the bookmarks) should give you a fair chance of repairing other parts of the circuit that are not mentioned here. The circuits are simple designs realised with the bare minimum of components necessary. They are fully serviceable by the average DIYer. The control unit for the boiler should not be powered up without some kind of spark plug connected. Doing this could damage the ionic flame sensing circuit. The ignition is a dual spark type, with the second spark occurring across a gap in the PCB inside the box.
The unit must be sealed tight to prevent gas from entering the box.
Please see the official manuals for general system wiring and system checking.
The Control Panel is mentioned later in this guide.
The lid is fastened by hooks and a sealant. It can be carefully pried off using a flat screwdr|