My steam boiler is set to 125 C and coffee boiler is set to 94 C but when the hot water is turned on there seems to be a lot of spitting and steam along with some water coming out. I remember seeing a video somewhere talking about that. I'd prefer the water to be hot, of course, but come out in more of a stream. Could one of the temperatures be set a little too high?

I don't have this machine but for me it not a pb of too high temperature setting.

I am interested by this machine with it's paddle for pressure adjustment. But could someone explain me of the pump is really managed when the paddle is completely closed. Since these is no sensor on it, that means the rotative pump stay working. So how is made the internal design of this machine to protect the pump in a such case.

Lelit just indicate « when Paddle is closed, water circulates inside the pump (ie OPV does not waste water). »

Internal water circulation inside pump ? Interesting but I have you idea of how it is made

thusband wrote:My steam boiler is set to 125 C and coffee boiler is set to 94 C but when the hot water is turned on there seems to be a lot of spitting and steam along with some water coming out. I remember seeing a video somewhere talking about that. I'd prefer the water to be hot, of course, but come out in more of a stream. Could one of the temperatures be set a little too high?

2 boilers
Brew Boiler - for espresso production
Service Boiler - for Steam and hot water. Steam comes from above the waterline, hot water from below it. So it's under pressure at about 1.3 bar.

Marco_83 wrote:I don't have this machine but for me it not a pb of too high temperature setting.
I am interested by this machine with it's paddle for pressure adjustment. But could someone explain me of the pump is really managed when the paddle is completely closed. Since these is no sensor on it, that means the rotative pump stay working. So how is made the internal design of this machine to protect the pump in a such case.

Lelit just indicate « when Paddle is closed, water circulates inside the pump (ie OPV does not waste water). »

Internal water circulation inside pump ? Interesting but I have you idea of how it is made

Rotary pumps used in espresso machines have what's called a "balanced bypass system" sprung valve connecting outlet with input in the pump body. When the pressure builds above whatever the spring tension is set to, water from the output is transferred to the input. If this happens for too long the water heats up because of the energy imparted by the pump and will eventually cause damage. For the relatively short times of coffee profiling, this is not a problem.

DaveC wrote:2 boilers
Brew Boiler - for espresso production
Service Boiler - for Steam and hot water. Steam comes from above the waterline, hot water from below it. So it's under pressure at about 1.3 bar.

Thanks, I thought that was the case. Is 125 C too high for the service boiler? Shouldn't the water come out in more of a stream? Was that one of your videos where it talks about how water should come out?

Very nice job, by the way, on all your videos. They've been very helpful.

DaveC thanks for your reply. This balanced system is in fact a sort of OPV no ? What difference with classic OPV added on pump outlets ?

I seen some pictures of Bianca where I recognize habitual rotary pump. No enough detail to see this balanced system. Is it integrated as part of the whole pump or just added functionality ?

If I change for a rotary pump, can I found and install this deviation system in complement of pressure adjustment paddle (to be sure to protect pump when paddle is closed).

Thanks, I thought that was the case. Is 125 C too high for the service boiler? Shouldn't the water come out in more of a stream? Was that one of your videos where it talks about how water should come out?

Water from hot water wands of most espresso machines comes from the service boiler. Because the service boiler is under pressure, that water is heated to over 100-degrees C (i.e., it's above boiling). The higher the pressure the higher the temperature. When superheated water is released through the hot water wand, it encounters normal atmospheric pressure. When superheated water is exposed to normal pressure, it instantly turns to steam. Hot water wands on espresso machines have a large tip with a screen. The idea here is that when passing the steam through the wand and large head, it will condense. When you first open the valve, the wand and tip are relatively cool; so you get more water than steam. But if you continue to draw water, the metal heats up and is less able to condense the steam back into water. That's why the sputtering increases.

Yes, if you lower the pressure (or temperature on a PID machine...same thing), you'll get more water and less steam out of the hot water wand. However, this comes at the expense of less steam for foaming. A better solution is not to use the hot water wand for hot water. Instead, fill a foaming jug with the desired amount of water, pop a thermometer into it, and steam it until it reaches the desired temperature. This will allow you to set your service boiler at the maximum allowed temperature/pressure for good steaming. Assuming you put good water into the jug, it will also give you higher quality hot water. When service boilers are used for steaming, which is usually the case, the mineral content of the water gradually rises. This is why it is a good idea to periodically purge your service boiler and refill with good water.

Thanks much for the information and very clear explanation. That idea of using a second jug for hot water makes a lot of sense.

Marco_83 wrote:DaveC thanks for your reply. This balanced system is in fact a sort of OPV no ? What difference with classic OPV added on pump outlets ?

I seen some pictures of Bianca where I recognize habitual rotary pump. No enough detail to see this balanced system. Is it integrated as part of the whole pump or just added functionality ?

If I change for a rotary pump, can I found and install this deviation system in complement of pressure adjustment paddle (to be sure to protect pump when paddle is closed).

The Expansion Valve (what you call the OPV) is also present on a machine with a Rotary pump as it allows the exit of water because of expansion through heating to prevent rupture of pipework, fittings HX or boiler. It's usually set to about 12 bar for this purpose and the balanced bypass of the Rotary pump regulates brew pressure and is set to 9 bar. They work in completely different ways.

A vibration pump machine ideally has the expansion valve set to 9-10 bar so it performs the dual function of venting excess hydraulic pressure due to water expansion and regulating brew pressure. It usually sends excess flow back to the tank, although some systems send it to the pump inlet tube.

A few machines mix water from the reservoir with water from the service boiler before it exits the hot water wand. That's seems pretty nifty though personally I don't use mine enough that I'd pay extra for that.

Perfect it is more clear.

If I want to order a rotative pump now, how can I be sure the balanced valve is present or not ?

So Bianco work on this principle to :

- Set the pression for extraction at 9 bar,
- Protect the pump during profiling when you reduce water flow with the paddle.

Correct ?

Is there a risk for this machine and the pump if you make a mistake and you stay with the paddle in closed position (water circuit closed in the group head) ? Because paddle is not instrumented.