Why do front loaders have drain pumps?

N

NinByChoice

Skilled
While top loaders have just a drain valve. This means extra initial cost and possibly costlier maintenance. Im pretty sure the pump uses more electricity than valves.

Are there any front loaders with drain valves?
 
Must be due to the way they are designed. The centrifugal forces push the water out - but there is no gravity to pull it out - so I guess a drain pump provides the suction needed.
 
NinByChoice said:
While top loaders have just a drain valve. This means extra initial cost and possibly costlier maintenance. Im pretty sure the pump uses more electricity than valves.

Are there any front loaders with drain valves?
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Where did you get the notion that top loaders do not have a drain pump ? How are they supposed to drain themselves otherwise. Though the idea of a valve instead of a pump is interesting and more durable, in theory why should a pump be required if a valve will do the job.

My old top loader has a drain pump, in fact it gave out recently and had to get it replaced. To my surprise they found one locally and fit it. The model is over two decades old and bought from abroad.
 
Only the outdated semi automatic ones don't have a drain Pump.

The front loaders have a pump because it can drain the water against gravity to a sink.
 
^^ Draining to a sink makes sense. But I don't think thats the case for most installations (?).

My assumption was because the fully automatic BPL and Sharp top loaders at home doesn't have a drain pump. The valve is connected to the lowest point of the drum and the water drains due to gravity. This made a lot of sense to me. Didn't know other top loaders have a drain pump.

vivek.krishnan said:
Must be due to the way they are designed. The centrifugal forces push the water out - but there is no gravity to pull it out - so I guess a drain pump provides the suction needed.
Click to expand...

I didn't understand this. The drain pump needs to be connected at the lowest point of the water drum anyway. A valve seems like a simpler/cheaper design choice.

Some of the front loaders also require that the drain pipe be looped above the water level (sometimes this loop is internal, before the drain pipe exits the frame, so might not be visible outside). Is this because the pump cannot stop the flow of water (when not turned on), causing all the water to drain out? Is this the case with top loaders that have drain pumps?
 
In my front loader the manual specifically states that the minimum height at which the drain pipe should be looped at which is well above the water level and yes this is because to stop the water from flowing out since the pump is located below the water level.
Its is cheaper to put a solenoid valve then to put a pump ,but the sole reason for the pump is to drain the water against gravity,but some machines may have both a valve and a pump(for places where the drain pipe end is below the water level).
 
NinByChoice said:
I didn't understand this. The drain pump needs to be connected at the lowest point of the water drum anyway. A valve seems like a simpler/cheaper design choice.

Some of the front loaders also require that the drain pipe be looped above the water level (sometimes this loop is internal, before the drain pipe exits the frame, so might not be visible outside). Is this because the pump cannot stop the flow of water (when not turned on), causing all the water to drain out? Is this the case with top loaders that have drain pumps?
Click to expand...

I dont know if my answer is correct - just a thought.

Since the drum is kept horizontally - water will collect at the bottom of the outer drum and a pump will provide a suction to draw the water out.
 
Auto front loaders need the exit pipe to be at a height above the entry water level at the back of the machine. So without a pump they can't expel the drainage water. Also these have a filter or trap at the bottom, this may have a role as well in the design.
 
vivek.krishnan said:
I dont know if my answer is correct - just a thought.

Since the drum is kept horizontally - water will collect at the bottom of the outer drum and a pump will provide a suction to draw the water out.
Click to expand...

There is no need for suction the water simply flows with just gravity.The Pump is there only to pump water against gravity.
 
Can somebody draw a simple diagram so I can understand?
If water drains through gravity shouldn't the drain exit be at lower level than input?
Why would a pump be required in this case?
Is the pump for throwing water over clothes from top of drum during wash cycle?
 
Yes water drains through gravity up until the PUMP/FILTER assembely from there there is pipe internally that goes up again.The pump is there only to pump out the drain.
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Well the reason for the drain pump is:
Front Loaders do not fill the drum completely with water
The amount of water is decided by the type of wash cycle chosen - Cottons/mixed/wollens etc.
To decide how much water is filled in the drum, there is a U-shaped drain outlet atatched to the drum.
when the water starts filling, the machine will fill some water, start rollig the drum, so that clothes can absorb the water, then stop, check with the sensors in the U-shaped water out pipe for the level of water...it will repeat ths cycle till the water level is in accordance with the wash cycle chosen.
Since the level of U-Shaped water out pipe is always higher than the maximum amount of water that will be filled in the drum, a drain pump is a must in Front Loaders.

If you got a FL, you can try one small experiment:
When the machine has finished filling water in the drum, and started with the normal wash cycle, open the detergent box and start filling it with water with a jug/mug. After some time, the machine will sense that the water level is above the set limits, and will automatically start draining out the water!
 
But even then there is no requirement for a PUMP.The water can still flow out the drain due to gravity with just a solenoid valve to control the output.

So as said earlier its there only to pump it against the gravity
 
The primary goal of drain pump is to give you the flexibility to install the machine at a lower level than the drain hole of your house. It's common to find drain pump in front loaders and nowadays, some top loaders are carrying it too. Drain pumps make installation of hidden hoses very convenient.
 
^ Looks like that is the correct reason. Thanks everyone!

I dont see many such installations in India though. I wonder if any manufacturer will make a cheaper front loader by not using a pump. But I hear that most manufacturers are just assembling kits from OEMs like Bosch.
 
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