Foot pump faucet drips when electric pump runs

[LifesBetterWhenYoureBeating]

Hi there,

I've just installed a fresh water foot pump on my galley, and it's connected via a T fitting to the same hose that feeds the electric water pump (like in the picture)

It's all working fine but every time the electric pump runs, a bit of water comes out of the faucet connected to the foot pump. I suppose it happens because the electric pump running causes a pressure buildup in that hose and that pushes some water in the direction of the foot pump? I'd love if someone could explain this to me, and specially if there's a way to avoid it

Thanks in advance

[ItDepends]

It's actually what is called "water hammer." When the pump is running, it is sucking water out of the tank and that water is flowing through the pipes. when that water flow is suddenly shut off, the water's velocity is converted to pressure, which pushes through the foot pump and out the faucet.

If you only use the foot pump as a backup the simplest solution would be to install a shutoff valve. Or a three way valve at the junction.

If you do NOT have an accumulator in the pressure side of the system that can fix it also, although its effectiveness will depend on exactly what kind of electric water pump you have.

[Jammer]

Use a longer suction hose between the T and the electric pump, ideally made out of soft rubber. Just make a couple of loops of hose or something. That will absorb much of the vibration and your problem will go away or at least be minimized.

[LifesBetterWhenYoureBeating]

Originally Posted by ItDepends

It's actually what is called "water hammer." When the pump is running, it is sucking water out of the tank and that water is flowing through the pipes. when that water flow is suddenly shut off, the water's velocity is converted to pressure, which pushes through the foot pump and out the faucet.

If you only use the foot pump as a backup the simplest solution would be to install a shutoff valve. Or a three way valve at the junction.

If you do NOT have an accumulator in the pressure side of the system that can fix it also, although its effectiveness will depend on exactly what kind of electric water pump you have.

Thanks for the explanation! I think I'll install a shut off valve close to the pump as the T is not as easily accessible

[LifesBetterWhenYoureBeating]

Originally Posted by Jammer

Use a longer suction hose between the T and the electric pump, ideally made out of soft rubber. Just make a couple of loops of hose or something. That will absorb much of the vibration and your problem will go away or at least be minimized.

Great to know that's a possibility but in my case the T is right next to the pump and it'd be annoying to have all that coiled hose there