Grundfos CM3-5PM would b sufficient

Wanna ask are these water-pump waterproof ? I recently bought some unknown brand water-pump for 1.9k and found out its not waterproof ....and the only place i assemble it is out beside my water-tank

Coz i bought the gas heather then the sales person ask me how many floor is my house, how many bathroom, how many kitchen bla bla then keep insist and promote the pump then i cincai say ok ......

Who know come my house install already only tell me not waterproof then i just take a pail and cover....kena chop vege head already

pump has to be installed before water filter.

1) THen u will have strong pressure to backwash the filter
2) If after filter, the filter will reduce incoming pressure further, hence less water for the pump to boost

Centralized pump flow will be too strong for instance water heater, you won't get hot water especially during rainy season.

Some instant water heater also state the max pressure it can handle in the instruction manual.