Baxi system 35/60 timer swap for DHW pcb?

[elsral]

Hi,
I have a baxi system 35/60 which currently operates on a timer inbuilt in the boiler.
I have then two twin valve circuits, 1 for radiators circuit and 1 for Hot Water cylinder circuit.

I wanted to change the system so that the thermostat associated with each of the circuits would start the boiler automatically as per each of the thermostat settings.
I connected the switched live from Radiators circuit to terminal 2 in boiler for control system and set the timer to always on, this setup works fine. However, if I connect the switched live of the Hot water circuit to terminal 2 aswell, they interfere with each other (if hw circuit fires up boiler, the radiators valve is open aswell and heats up radiators when not required and viceversa)

If no other solution possible with current setup, I was thinking of replacing the inbuilt timer with the DHW PCB (which as per the installation/servicing manual occupies the same area in boiler) (my boiler has not DHW PCB).

Would this be as simple as ordering the part and replace the timer with the DHW pcb and then connect the DHW feed to it? Current timer connects into 4 pins on main PCB (with two black cables and 2 brown cables).

Thanks,
Elsral

 

[baxpoti]

Replacing the timer for the DHW PCB will resolve your problem.
DHW Relay PCB Part No. 248620
Refer to installation manual, wiring diagram, scheme 2 for correct set up of 'S plan'
The wires to the timer will need the two blacks linked and the line and neutral wires made safe.