Profitec Pro 800 - high boiler pressure, direct water connection

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#1: Post by DHMJE »

Dear all,

Yesterday I plumbed in my Profitec Pro 800. A direct water connection via BWT pressure regulator set to 2.8 bar, a Bestmax premium filter and the aquameter.

Everything seems to work okay except one strang behavior. The boiler pressure indicator goes rapidly to 2.5 instead of 1.25 bar.

When I turn on my machine the boiler fills to 0.3 bar. You hear a click and then the heating starts. Within 15 minutes the boiler pressure exceeds 2.0 bar. Desired water temperature (124 C) is by then still not reached.

Untill yesterday I used the water tank. The boiler pressure never exceeded 1.3 bar at a temperature of 124 degrees Celsius.

Noteworthy, when I shut down the machine the pressure declines rapidly to 1.25 bar. From there on it declines slowly. Likewise with my previous use with the water tank.

I don't dare to leave the machine on to use it for making coffee. First I must know if this behaviour is normal with a direct water connection or if something must be repaired.

Can you help me out?


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#2: Post by homeburrero »

I'll make a guess, since no one else has yet replied. Others with real experience on this machine will hopefully chime in.

My guess is that your anti-vac is stuck closed, or perhaps is prematurely closing while the boiler is still partially full of air, and that allows it to build a high pressure before it comes up to full temperature. If there is just water and water vapor in the boiler, then you can expect a very predictable relationship between the boiler temp and the boiler pressure. But if there is air in there it can reach a high pressure well before it's up to the setpoint temp. One key purpose of the anti-vac valve is to allow air in the boiler to be replaced by steam when the machine is initially heating up. The fact that yours is showing .3 bars before the heater kicks on indicates that your anti-vac is closed before it starts heating and producing steam.

To test this you can simply open the steam wand when you turn the machine on, then close it after it has blown off a few seconds of steam. It should then hit the expected ~ 1.3 bar when it reaches 124C.
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DHMJE (original poster)

#3: Post by DHMJE (original poster) »

Yes! That's it. It now works completely fine. Thanks a lot!