Hello,

I haven't been able to pull a decent shot in a long time on my father's E61-based machine, a Fiorenzato Bricoletta Volante (which after being serviced multiple times is more Bezzera now than Fiorenzato by the way). The shots always end up underextracted, pale and rather lukewarm, which made me suspect a temperature problem. I tried descaling it for a few hours using Dezcal (as far as I know, the machine has never been properly descaled after several years of daily use -- yes, I know...) but that didn't help much. The water temperature right out of the group is 68°C, and the water coming directly out of the water wand is around 92°C, which would indicate it's not nearly hot enough in the boiler. Yet, surprisingly, the pressurestat shows 1.2 bars.

Since I'm no expert and had practically never opened a machine before I started trying to fix that thing, I would appreciate any pointers you could have.

There could be a slight leak going on - somewhere.

Pressure and temperature are directly related. If the steam boiler is 1.2 bar, you should have very good steam from the wand, ample, strong and dry steam. If it is weak, or it depletes quickly, the water level in your boiler may be too high. The water sensing probe could be scaled or misadjusted. The fill point is critical in that it has to completely cover the heating coil, but you need enough space above it to have a good steam area. If it is too low, then the heat exchange tube may not fully heat the brew water.

The hot water tap - after a few seconds, you should get sputtering and very hot water, quite near boiling. Remember, as soon as water hits atmospheric pressure, some will turn to steam phase and the liquid can be no hotter than just under boiling point. ( < 100c). If you are much above sea level, then the water liquid will be lower temperature as the boiling point reduces with increasing altitude.

There are two water circuits in your machine. The boiler, which creates the steam and hot water and the brew circuit, which circulates water through a closed tube that passes through the steam boiler. The two water flows are isolated by the solenoid valve that allows the pump to fill the steam boiler when it is low. Other than that, the loop between the e61 brewhead, the heat exchange tube and the water pump are a closed system.

So - the brew head, if the machine is idling and fully warmed up for say, an hour, is the metal surface of the brew head very hot? Are parts of it cooler to the touch than they should be? If so, then the water circuit for the brewhead is leaking somewhere, perhaps internally. Have you serviced the e61 valves itself? If they are not seating properly, that could the problem in that the water is not circulating properly and leading to low brewing temperature.

It is also possible that something is blocked and not allowing for good convective flow of water in the brew group while the system is idling.

Given that this is a problem that just showed up some time back, this suggestion below may not apply. If the machine does not have a vacuum relief valve, also called anti-siphon valve, it may suffer from what some call false pressure tripping the pressurestat. If you open the steam tap briefly to relief pressure and let it reestablish, that might help. You might also connect a hose and pressure gauge to the steam wand (clamp it well with hose clamp) and confirm the machine's gauge is accurate.

I offer this because it is simpler than diving into HX section and looking for blockages, etc. Also, if you have the means, measuring the boiler temp would be help.

nuketopia wrote:Pressure and temperature are directly related. If the steam boiler is 1.2 bar, you should have very good steam from the wand, ample, strong and dry steam. If it is weak, or it depletes quickly, the water level in your boiler may be too high. The water sensing probe could be scaled or misadjusted.

Since the descaling, I've used the steam only a handful of times. What I got was good steam, as far as I know, but not in a steady flow as there are some fits and starts. And at least once, the steam depleted after a few seconds.

The hot water tap - after a few seconds, you should get sputtering and very hot water, quite near boiling.

The two times I measured the temperature, I got 92-93°C.

So - the brew head, if the machine is idling and fully warmed up for say, an hour, is the metal surface of the brew head very hot? Are parts of it cooler to the touch than they should be? If so, then the water circuit for the brewhead is leaking somewhere, perhaps internally. Have you serviced the e61 valves itself? If they are not seating properly, that could the problem in that the water is not circulating properly and leading to low brewing temperature.

No, not as it used to a few years go. I remember not being able to even touch it, whereas now I can rest a finger on it for 2 seconds maybe. I could even leave my finger on the mushroom before I descaled it. Now it's noticeably hotter but still not enough it seems.
No idea about the valves, but if it were leaking, even internally, then shouldn't I be able to notice it? Wouldn't there be water in the machine or under it?

It is also possible that something is blocked and not allowing for good convective flow of water in the brew group while the system is idling.

How do I find that out? Is it not also possible that the pressurestat is faulty?

Thanks for your reply!

dsevier wrote:Given that this is a problem that just showed up some time back, this suggestion below may not apply. If the machine does not have a vacuum relief valve, also called anti-siphon valve, it may suffer from what some call false pressure tripping the pressurestat.

I'm not sure but if you're referring to the valve on the top of the boiler, then I think it does have one.

Also, if you have the means, measuring the boiler temp would be help.

I wouldn't know how to do that. But isn't measuring the water from the hot water tap a pretty good indication already?

To check the pressure stat =

Look at the boiler pressure gauge. Fully warmed up, open the steam for several seconds. Let the boiler come back up to temperature and the heating element turn off. (if you have a light that's nice, if not, just listen for it to stop boiling), should be around 1.3 bar, or just below.

If you open the steam valve briefly (like just open and rapidly close for a spurt of steam) you should see only a small drop in pressure. Normally, the boiler heater will not come on right away. Do this several more times until the pressure drops enough that the pressurestat turns the boiler heater on and note pressure on the gauge when it does.

The set point is where it turns off when it reaches the desired pressure. The dead-band is the pressure between the high point when it turns off and the low-point, when it turns on the heat. You'd want a deadband of about 0.2-0.3 bar. Probably no more than that.

nuketopia wrote:To check the pressure stat =

Look at the boiler pressure gauge. Fully warmed up, open the steam for several seconds. Let the boiler come back up to temperature and the heating element turn off. (if you have a light that's nice, if not, just listen for it to stop boiling), should be around 1.3 bar, or just below.

It settled at 1.2 after 10-15 seconds. But the steam was ejecting in spurts, as I said earlier, not in a steady fashion.

If you open the steam valve briefly (like just open and rapidly close for a spurt of steam) you should see only a small drop in pressure. Normally, the boiler heater will not come on right away. Do this several more times until the pressure drops enough that the pressurestat turns the boiler heater on and note pressure on the gauge when it does.

The set point is where it turns off when it reaches the desired pressure. The dead-band is the pressure between the high point when it turns off and the low-point, when it turns on the heat. You'd want a deadband of about 0.2-0.3 bar. Probably no more than that.

If I understood your instructions, low point-->1.2; set point-->1.4
So in the light of all that, it would seem it's not the pressurestat. Correct?

Water normally condenses in the steam wand when its idle and may take a couple of seconds to clear when first opened, but after that the steam should be steady and without any liquid water droplets or spray. If its 'wet' after the first couple of seconds its likely the boiler level is higher than it should be. Check the level probe is clean and inserted to the correct depth. The machine is plumbed right? If so then high boiler level can also be caused by fill solenoid leaking

No, I'm using the water tank. How do I know if the level probe hits the correct depth?

Any chance you are using RO or distilled water? The water level sensor needs some minerals to work properly.