solder cracked on pcb potterton profile 60e?

Intermittent clicking noise and occasional sparking. Having seen the solder joints clearly with a magnifying glass the cracks were obvious on the sparking connector. Turned power off and resoldered then checked with circuit tester to ensure joints were sound.
When I reconnected all leads and powered on, only the pump could be heard at switch on. Tried the reset button just in case, but still no action.

Any ideas?