The plumber who was fixing my water pump a couple of days ago said the water should go straight from the street to the house, and the tank should be a backup (the tank is on the second floor). The guy from Home Pro, who installed the pump, said the water should go from the street to the tank and then into the house, otherwise why have a tank. Is there any reason to prefer one way over the other? Can the water sit in the tank indefinitely?

Is the pump you have for increasing the water pressure? If so and your system is set up with the street water feeding the tank and the pump to increase the water pressure to the house you are fine. You should have a separate valve to bypass the pump for when then power goes out so you can just rely on gravity feed from the tank

2 hours ago, kiteman9 said:

Is the pump you have for increasing the water pressure? If so and your system is set up with the street water feeding the tank and the pump to increase the water pressure to the house you are fine. You should have a separate valve to bypass the pump for when then power goes out so you can just rely on gravity feed from the tank

Thanks for replying.

The pump is for increasing the water pressure, but the system bypasses the tank. The street water comes straight into the pump, gets boosted, then into the house. The Home Pro guy set it up as you described, the plumber switched it around. Should I have it switched back? Does it matter one way or the other? Each guy acted like the other was a numbskull, that's why I wonder.

I would switch it back for 3 reasons. You need to keep the water in the tank circulating. For having water when the village water supply is not functioning and to be able to use gravity feed water from your tank when there's no electric. By putting a valve that switches the flow of water straight from your tank to the house that bypasses the pump. Find another plumber 

It is not a good idea (illegal) to pump direct from the mains.

 

If the mains pressure is low your pump will create a negative pressure in the supply pipe meaning that any "leak" will instread draw water into the pipe, maybe your neighbour has a hose in his duck pond, duck poo in your coffee anyone?

 

Do it like this:-

 

Thanks folks for the answers. Gotta change plumbers ????

 @Crossy 's diagram is the way to go !

 

At our house in Ubon the mains pressure is never sufficient to fill a tank placed anywhere except at ground level, so just check your tank will fill OK on a higher floor.

 

For our commercial premises we have to transfer from the ground level tanks to those in the roof space so that water is available by gravity when the upstairs pump is off due to power outages, even then there is insufficient pressure for a hot shower to run but at least the renters can flush their toilets.