Strange new flojet behavior with group boiler

[Madroaster]

Hi All,

Quick background on equipment: I'm running a V2 from a flojet on 15A. Water path is bottle->flojet->softener->carbon->T-junction for water tap->V2. The machine is 2 years old and spent its life plumbed in on 20A. It's only been on the flojet for 2 months for a temporary move. On to the problem...

The group boiler causes the flojet to pulse on and off throughout the shot. With each pulse the group pressure gauge drops to 7ish bar and then jumps back up to 9ish. This is annoying and noisy, and is probably impacting my shots. But the reason I'm writing is because this is new behaviour-- when I first installed the flojet, it didn't do this. The group boiler drew water as needed, but usually went an entire shot without drawing water.

Two weeks ago I replumbed the flojet system to include the water tap, and I reversed the filters (it was previously carbon->softener). After I did that, the new behaviour started.

I can recreate the flojet behaviour with the water tap by opening it just slightly. The low-volume flow from the tap causes the flojet to pulse just like it does with the group boiler.

I don't know what is wrong and I'm not sure where to begin looking to solve the problem. The steam boiler fills normally and doesn't cause the pulsing. The water tap doesn't cause the pulsing, except at the lowest flow rate. Running a blank shot through the group does cause the pulse, just as it does with a regular shot.

Anyone have any ideas?

Thanks,
--Derek

[chas]

It's a known issue when using a Flojet. You need to add an Accumulator tank at the output of the flojet. Then the output of the accumulator tank goes to the VII.

See this thread for additional information. viewtopic.php?f=13&t=147&p=1103&hilit=accumulator#p1103

You should also use the Search option to search on "accumulator". This solution has been discussed in a number of threads over the years.

[Madroaster]

Thanks. I have read about the accumulators actually, but forgot about them once everything was running correctly (after my initial flojet setup). I guess I'll have to order one.

[chas]

Everyone that lives in a house with a well also has a large accumulator for exactly the same reason.

[Madroaster]

Everyone that lives in a house with a well also has a large accumulator for exactly the same reason.

So if I'm understanding correctly, an accumulator is just a pressure tank?

[chas]

yes