Emc2 It sounds like the machine has a blockage specifically in the water wand.
I asked the questions, because I didn’t want you to work on something that might not be the problem. It could have been.
- machine going into standby, drawing a little water is enough to cool the boiler enough that the vac breaker pin drops and it is depressurised, only a dribble coming out
- if the gauge pressure matches what should be the correct temp, then that indicates the gauge and temp sensor are not faulty
- if the steam comes out good and strong and is maintained pressure doesn’t suddenly drop away, then theres no sticking vac breaker.
So we’re left with the blockage.
- remove the perlator from the bottom of the wand, is it blocked, does water flow well without it? = no
- remove the wand from the valve, does the water flow well now = no
- then it might be blocked at the point it exits from the boiler, or in the valve body itself
- try descaling the service boiler, and try to run water out of the steam want a bit when descaling.
If the above doesn’t fix it, then you will have to start removing pipes…..which we can cover later.