Hi i just install water heater today but during usage of heater, i heard my main mcb has buzzing sound. When turn off heater, the buzzing went off. Is it normal? Thanks

Ok sure, will do. Thanks for advise ☺

Hi need advise here. Last year my newly installed water heater caused my mcb to make loud buzzing sound when turn on. As suggested by ozak, i ask electrician to change mcb and the sound stop. And today, after 1year, i just noticed that the buzzing sound coming back but it was less noise compare to previous. So was it normal or is there any other issue causing mcb to keep getting spoilt?

Ok, will request my eletrician to change & secure properly. Is there any other possibilites that might causing this? Btw, the water heater adapter was split out from the fridge adapter. Would this be root cause?