The unit does not heat up but the relay clicking sound can be heard. So I check the heater filament and the relay. It shows filament is fine but the continuity of the relay output is open even during ON.
The board is not available online so I just search for the relay at Element14 website.
I managed for find a relay having the same specs.
After replacing the relay, everything works fine.
(Something wrong with the site, I can't attach photos even with <3MB file size)