No bypass from tank but pressure from tank

Can’t figure this one out…

Getting pressure drawing from buffer tank, so, it’s drawing water, but no flow through bypass hose when off trigger.
When garden hose is connected directly to inlet, I get bypass flow.

5.5gpm belt drive
55 gal buffer
3/4" feed to PW inlet
Have tried multiple ports on unloader for bypass
3/8" bypass hose

New build this year.

thx in advance chaps.

Garden hose direct to inlet

Got video coming…

I guess I’ll try another unloader.

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Take a good picture of unloader so we can see how it’s plumbed up

Does the link work to the video? It shows it there.

Yes it works….

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Aside from the bypass situation, I’m not feeling the two 90 degree bends.

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First you need to fix the restriction on the inlet before going on to the unloader
You have Two inlet filters. Filter 1 is off your tank
But somehow you also have another filter,filter link
This second inlet filter is designed for a garden hose inlet not for a suction fed pump.
Remove second filter and plump directly. Then see how it performs before spending $ replacing the unloader


At 0:21 of the video, it shows the pressure switch for the unloader. What exactly is its purpose? I’ve searched high and low here and on YT and I can’t find the answer.

Since, making this vid, I replaced the unloader with a ZK1. But I’m not getting pressure now. Pump is GP and brand new.

While troubleshooting, I took off either unloader and just left the OUT port on the pump open. When I started it, there was no increase in pressure, just the flow from the garden hose, which was hooked directly to the pump.

I’ve changed an unloader before with no issues. I’m at a dead end right now.

Would disconnecting the wires from the pressure switch of the original unloader have any bearing on getting no pressure?

Btw, I did remove this. It didn’t make a difference but I appreciated the suggestion.

No, that pressure switch is for burner control. Are you turning the adjustment bolt CCW to increase pressure? If so you may want to replumb and eliminate the unloader from the mix to see if it’s the pump causing the issue.

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Thank you bro.

Yes, and there’s no increase in pressure.

Yeah, I’m starting to think that it’s the pump. :triumph:

Pump, jumper hose then a gun with a trigger that’s been cable tied open. Fire it up and get an answer quick


Yasss, gonna do that right now

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For anyone reading this, The answer was that the pump had a clutch. The black pressure switch on the unloader was for that, not for a heater.

So, in bypass, the clutch turns the pump off, thus no water.


Yes….that pump should hold up longer than most having that clutch.