The pump is ard 0.5kW only, if you do not turn on the water, the pump will b in standby mode and would not consume much electricity. Your water heater is 3.6kW while a Grundfos water pump consumes 7times less electricity compared to your instant heater.

Some houses cant hear anything at all while some will have bombing noise. What i can tell u is Grundfos pumps have low noise operation, whether u can hear it or not is depending on how your plumber install it and the structure of your house. If you wan to know more, u can speak to my dad, can learn a lot from him.

hahaha, we will have raya promotion from 23-27 August. One of the promotion item is Grundfos + Water Filter package. Grundfos will send their demo truck to our showroom during those few days, u can come and have a look.

Here is the pump that i m using but this model has been discontinued. Grundfos CH-PC model is slightly noisier than this.