M
mikedavies
potterton suprima 80l 12 years old original pcb fully pumped system. Boiler temp setting just over half way. Seemingly random intermittent lockout , also random intermittent “knocking”. When working “normally” light sequence is as follows. Programmer on and heat called boiler fires solid green. Boiler temp satisfied stops firing solid red with slow flashing green until fires again red goes out and solid green. Demand satisfied or turned off green stops solid red on. Pump overrun seems correct and pump operation seems correct. Solid red stays on until next call. Very much appreciate if anyone can comment on whether sequence is normal and if not does it indicate either boiler themostat problem or pcb problem (am aware of the Suprima pcb issues). Thank you. Mike
