Have portafilter pressure gauge, check hot or cold?

[ristrettobrain]

I received my portafilter pressure gauge and installed it on one of my portafilters (rarely used since the arrival of my wonderous chopped portafilter!).

The machine was hot when I first assembled it so I immediately gave it a try and got about 11.5 bar. However, the glass on the gauge face fogged up quite a bit and stayed that way for over a day. This made me wonder if I made a mistake by testing with the machine hot. So I called the supplier and asked to talk to a technician. The technician said that the condensation was normal and that I should definitely measure with the machine (ECM Giotto Classic) hot.

Why would this be? I measured later with the machine cold and got about 11.5 bar again but unfortunately I did not note the pressure precisely when I meaured hot. Should there be a diffence in the OPV valve regulation or the pressure gauge reading between hot and cold. I would rather not get the condensation inside the gauge so I would prefer to measure the pressure with the machine cold. Is there a problem with doing it this way?

Thanks in advance,

Ristrettobrain

[Abe Carmeli]

Should there be a difference in the OPV valve regulation or the pressure gauge reading between hot and cold. I would rather not get the condensation inside the gauge so I would prefer to measure the pressure with the machine cold. Is there a problem with doing it this way?

.

There shouldn't be any difference between cold or hot. The OPV regulates water pressure when it is cold and before it enters the boiler anyway. You got it foggy probably because you did not flush your machine before you pulled the shot. The water was way too hot.

[ristrettobrain]

Thanks again Abe. I did not see why it would matter but you (or at least I) never know.

[DaveC]

I would imagine it's a good possiblity that the bourdon tube within the gauge may be cracked and it's fogged up because it leaks. It may not get worse, but chances are it will, so might be an idea to see if you can get another gauge. It may also affect the accuracy slightly and more if it gets worse.

I don't understand why the technician told you it is normal....in my own experience, it's not normal and my own gauge doesn't do that (hot or cold). If it was normal, we would all have fogged up pressure gauges on our machines?.