Vent the garden pump

Garden pumps are paid little attention as long as they serve. But if it comes to a defect and the water pump has to be replaced, this also means a bleeding the garden pump. Here's how to vent your garden pump.

Distinguish the pump types of garden pumps

Of course, it can happen that an installed garden pump suddenly and apparently quit their service. Also in this case, bleeding the garden pump can often cause the pump to work correctly again. For this purpose, it is initially important to differentiate the water pump used as a garden pump according to their mode of operation:

  • displacement pumps
  • suction pumps

Displacement pumps are most commonly used

Displacement pumps set the pumped liquid (in the case of the garden pump water) in motion and promote it. A typical displacement pump is the centrifugal pump. Since it can not suck in water and air practically can not be displaced deliberately, such a pump must be vented. Therefore, these pumps are usually immersed in the medium to be pumped, which is why they are again referred to as submersible pumps.

The seemingly self-sucking centrifugal pump

This pump must therefore be exchanged necessarily in the medium to be pumped. But now there are actually centrifugal pumps, which are offered as self-sucking pumps. This is only partially correct. Even these pumps can not attract water when in between a piece of pipe must be overcome with air. The direct intake of these pumps must also protrude directly into the fluid to be pumped. Alternatively, the suction line must be adapted to the characteristics of this supposed suction pump:

  • They vent the suction line before each use
  • They install a foot valve on the lower pipe end immersed in the pumped medium

The foot valve on the intake manifold

The foot valve acts like a check valve. Water that is in the suction line can not flow back out into the tank or well out of the suction line. So if you want to install a pump, make sure that this foot valve is present or functioning, and also that the line is completely filled with water.

Bleeding the garden pump

Bleeding the garden pump itself is then easy with such a type of pump. The pump has a cap (like some motorized oil filler cap on some mopeds) that you can unscrew. Then fill the pump with water until it runs out. For some pumps, you must also add water during operation. Therefore, you should always read the operating instructions for the garden pump you are using.

Non-sucking pumps - bleeding does not help here

The second type of pump are then self-priming pumps. However, these are not centrifugal pumps (please do not confuse them with the supposedly self-sucking centrifugal pump!), But mostly around so-called piston pumps. These pumps are actually self-priming. However, you must absolutely take into account the specified delivery height of the pump. In addition, the suction line must also be in relation to the pump capacity.

Tips & Tricks

The head of a pump does not refer to the geodetic head (geodetic means a normal height difference such as on a hill), but to the possible height of the water column in meters, which can promote the pump, so in the case of a suction line to this length, the The water column in meters indicates the negative pressure that a pump can suck. Between our atmospheric pressure and a pressure of 0 one speaks of negative pressure, under zero on the other hand begins the vacuum, which pumps, if at all, can pull only in a completely closed system.

When venting a centrifugal pump must be really completely deaerated. Even high-quality pumps can no longer deliver air with a share of more than 8 percent. However, if the suction line is leaking, air is sucked in and cavitation occurs. Under "Garden pump does not suck" you will learn what can be responsible if you can not vent the pump as it should.

Video Board: Why Your Sump Pump Needs a Vent Hole