Air lock at pressure regulator

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Mat-O-Matic
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#1: Post by Mat-O-Matic »

I recently installed a pressure regulating valve and experienced a problem with air lock. Is there is a process I should follow to avoid air lock? What should I look for elsewhere in the system to troubleshoot?

A diagram of my plumb setup is attached. Overly exhaustive contextual info below.

1998 Elektra Sixties A3 La Deliziosa
3/8" John Guest fittings from supply through the regulator, then a T fitting and adapter to connect 3/8" braided hose, one outlet to hose for purging/drawing in descale, etc., the other is braided hose to the Elektra's input. (Flexible hose for drain has a vent built on to prevent slow drain if slope is compromised.) Regulator is from Clive Coffee.



Old house has a 1/2" copper main and low pressure overall. It fluctuates between 40 and 60 psi. The Elektra would prefer ~25psi.

I installed the regulator and set it to its lowest setting, and the dial read 35psi. Inlet gauge on the A3 read a little above 2 bar. Good enough, Yay!

I flushed the machine with a blind to set the pump pressure to ~8.5 bar. Access to the valve is challenging because I was too lazy to take the sides off, and it took a few tries with tool drops, mild burns, cussing, etc., to get the pump set.

Foolishly, I started a load of laundry. The regulator gauge dropped to 20 psi. After the laundry stopped, the regulator still read 20 psi (I did not note the inlet pressure on the A3). I fiddled with the adjustment on the regulator, but the gauge did not change significantly from 20 psi. I decided to go back and see what was happening with the pump pressure in the A3.

The last few times I was running the pump, it made clacking sounds as if it was running dry, but that resolved as I adjusted the pressure. As I increased the pressure to about 3 or 4 bars it sounded ok, then got really loud and clack and the pump needle shook violently, and then it calmed down again as I neared 8 bars and then my target.

When I next looked at the pressure regulator's gauge it had dropped to zero, and did not respond to valve adjustments. With some effort I removed the valve which had substantial pressure built up ahead of it and there was a fair amount of fast discharge. I reset my plumbing to its previous configuration which is the same as the illustration attached, but without the pressure regulator.
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HB
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#2: Post by HB »

With water pressure dropping to 20 PSI and the resistance of the water filters, the flow to the pressure regulator would be a trickle. The noise you heard was the rotary pump cavitating (think sucking on a very thin straw). Adding a check valve then an accumulator after the water filter would smooth out the momentary pressure drop when a toilet flushes or the washing machine starts.
Dan Kehn

Mat-O-Matic (original poster)
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#3: Post by Mat-O-Matic (original poster) »

I appreciate the reply and bought a check valve and accumulator but haven't yet had time to install them with the regulator. Running the A3 on mains pressure and am excited to see consistency improve but am very happy with my shots regardless.
Clive Coffee responded that it is possible I shut the regulator valve down to zero, and indicated a way to use the shutoff valve to read the pressure on the regulator with greater reliability. I'll do that when I install everything.
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truemagellen
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#4: Post by truemagellen »

I would recommend a backflow preventer on front end, then regulator, then filter, then Y going to a filter flush valve on one side of the Y and the machine the other side. Your machine might have a backflow preventer built in too.

I used to have a similar problem to you due to the location in my prior residence and location of filter where it would start to drain out a bit out of the filter and create an air pocket. I could overcome with an initial long flush like priming a pump but who knows if I was causing pump damage. Eventually I found that making sure all the fittings were in very tight and no chance for it to release air the problem went away but I should have put a backflow/one way on it but I switched to a lever that had no pump and no longer was an issue.

Here is my setup, my plumber does commercial espresso/coffee machine installations so he is using commercial fittings but in a home John Guest is fine. Also I have a commercial backflow preventer that goes to drain but you dont need that, just a regular one way/backflow device.

Also ignore the hammer mechanism coming out of the wall, I have very high pressure starting and wanted to reduce the thunk sound.


Mat-O-Matic (original poster)
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#5: Post by Mat-O-Matic (original poster) »

Can someone chime in with instructions on setting the regulator? The behavior of the regulator doesn't really match the instructions I got, and I saw in a 2015 post that the group should be flowing while I adjust it?
I thought I should adjust the regulator to 1.7 bar (turn on water source with stop valve closed on opposite side of regulator valve, read gauge, turn off source and vent, adjust and repeat), then adjust the pump to 8 bar while running, then adjust the pump to ~9 bar while pulling a shot. This is what I've done. However, the regulator (which has not behaved entirely predictably) is showing 25psi as I set it, but the inlet pressure on the machine still shows over 4 bar. It's all very crazy making.
[I did get an accumulator, too, but gave up on installing that today as it felt like one more point of uncertainty in the system.)
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truemagellen
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#6: Post by truemagellen »

Yes I set it while it is flowing only as it will rest at a higher static pressure. This is the problem with pressure regulators that don't have a return.

Ideally I would have a setup with a gauge before to read line and a gauge after the filter before it enters the machine.

The filter and other fittings and hoses reduce pressure further before it enters the autofill solenoid of the machine.

Mat-O-Matic (original poster)
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#7: Post by Mat-O-Matic (original poster) »

& am I supposed to somehow disable the motor on the rotary pump?
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