Lelit Bianca hissing - Bella barista warranty question

rivergo1d

My Bianca has suddenly developed a hissing. On my old cherub, this would often be a valve which needed a quick tap.

But my Bianca is still under warranty, and what I don’t know is if they would allow me to take the cover off to triage what is going on, rather than undertake an expensive and back breaking return to base.

I notice recommendations about periodic covers-offinspections for leaks anyway as good practice for nipping problems in the bud… is this on warranty-wise?

I can of course call BB on Monday, but I have all day tomorrow to investigate…

DavecUK

rivergo1d The top cover and case is designed to be removed, there are no security screws, would be hard to see what the problem was with removing it if it was just for observation and diagnosis? If it’s hissing, the only way to diagnose the problem is to open the top and look.

There is one key bit of information missing to locate which boiler/fittings has the problem and possible causes.

Does it hiss when the steam boiler is not enabled and under pressure?
What water do you use, how is it treated and if it’s tap water or treated tap water, how hard is the water in your area.

Penance

I had the cover off on second day of owning my Bianca. There no harm in looking.
There are no warranty seals on the cover.

rivergo1d

Thanks guys, I’m out and about today so will de-cover it tomorrow and take a look. I use Ashbeck water. The machine is v3, 8 months old and tends to be switched on for an average of 17 hours a week.

It seems to stop for a while after my final purge of the steam wand, but I’ll definitively narrow down which boiler it is tomorrow.

MediumRoastSteam

rivergo1d - do you see steam coming out into the drip tray via the outlet at the front?

If so, it will be one of the valves (rather than a leaky fitting).

MediumRoastSteam

rivergo1d Holding up a piece of paper between the vacuum breaker and the central fixing,

So the vacuum breaker valve routes to a connector which ultimately takes the water from the expansion valve (normal), vacuum breaker (normal), and Safety valve (not normal), and that is diverted to the drip tray. That’s why I wrote this:

MediumRoastSteam do you see steam coming out into the drip tray via the outlet at the front?

When the steam boiler reaches approx. 99C, the vacuum breaker will start hissing. Some steam, water and condensation will splutter and that will end up on the outlet at the front of the machine which then empties into the drip tray.

So, if it is the vacuum breaker that’s hissing, and this is when the machine warms up, and you see that on the outlet at the front, there’s nothing wrong with your machine.

If you see or hear the vacuum breaker hissing outside of that timeframe (i.e.: it should not happen if the boiler is fully up to temperature, as it will be closed by positive pressure), then it’s not working as intended. Regardless, you will not see condensation inside the machine, because it goes to the drip tray.

If there’s hissing on the vacuum breaker and it’s not ending on the drip tray… Then it’s either the fitting that’s not sealed properly against the boiler or it’s not the vacuum breaker. 😃

Ernie1

When I had the Bianca it started doing exactly the same around the same time of ownership, I also used bottled water and powered it on about 14h a week.

Mine was one of the valves on the steam boiler, but before I attempted to make any repairs it mysteriously just stopped and didn’t happen again.

rivergo1d

OK, so this is the culprit. The joint connecting the pipe from the steam boiler to the steam arm. I can see it spitting water. Nice and accessible, no can of worms to open.

So, am I best to tighten this nut with the machine cold or the machine hot? Do I need to take care to brace any other part of the machine while I do so?

DavecUK

rivergo1d Tighten when cold would be my recommendation. You need to try support the steam arm side at the front in case it tries to turn. I can’t think of an easy way of doing that as it’s all tightened from the nut on the back of the panel and you don’t want to damage the finish. It probably won’t move, but even some hand support can’t hurt for the method I’m going to propose. Unplug the machine:

Put an open ended spanner on that nut, and shock it tighter using a larger spanner (not a hammer). As we are looking at it, shock it in the clockwise direction (looking from the rear). Sharp taps, don’t try and torque it up. You will see it move a little and when you think its tight enough (remember it’s a compression fitting) not a fuck me that’s as hard as it can possibly go fitting.

Power the machine up with the lid off and turn on the service (steam) boiler, watch for any leaking…if it does. Unplug and while hot, tappy tappy as above until it stops.

rivergo1d

Thanks Dave, that joint is now sound after a few taps of the spanner.

There are no other water leaks, but I can hear hissing from the other end of that pipe where it joins the service boiler. I’m not sure if this is normal behaviour for a Bianca. I don’t see big drops in pressure.

Should I tighten that too or leave it as there is no sign of moisture? I don’t want to harm a boiler fixing, but equally I don’t want it to corrode there over time.

MediumRoastSteam

rivergo1d There are no other water leaks, but I can hear hissing from the other end of that pipe where it joins the service boiler

Observe condensation on a dental mirror to see if there’s a leak.

DavecUK

rivergo1d if it’s hissing after it’s warmed up, then it could be loose? Check as per @MediumRoastSteam said. Otherwise you could be confusing it with a normal sound. 2 loose connections is not that likely, although whoever fitted that pipe would have done both ends!

John_Yossarian

If hissing upon heating it could be the vacuum valve. It is normal before it closes fully.

rivergo1d

Thanks MediumRoastSteam, Dave and John.

I’ve finally had a chance to check it out with a small mirror, and I cannot say that I detect any misting or even moisture on it. I’ve also tried wrapping a tissue around the joint, and I cannot really detect any dampness after 15 seconds.

If I switch the machine off, the steam pressure drops only gradually with time (I’d be curious about what a normal pressure drop rate is).

Although it’s close to the vacuum breaker, I was sure it was the central fixing. I was wrong.

Holding up a piece of paper between the vacuum breaker and the central fixing, it’s now very clear to me the noise is coming from the vacuum breaker.

Thanks everyone for the tips, on this basis, I’m inclined to leave it well alone.

rivergo1d

Oh I see, this happens while the machine is stable and at temperature. I’ll take another look at the drip tray when I have it powered up again tomorrow.

The hissing is not very loud at all, and it’s possible I only noticed it because I’d been working on the steamer outlet but and had the covers off.

Is it ok to use washing up liquid smeared around a fitting to detect leaks via bubbles?

MediumRoastSteam

rivergo1d - If you can’t see condensation with a dental mirror, I doubt the washing up liquid trick would do any better. With regards to usage, I don’t know. I never used it myself (and potentially would not).

John_Yossarian

rivergo1d If the hissing can be heard after the machine has reached the pressure/temperature then it could be that something prevents the vacuum breaker to close fully. Cleaning it usually helps. If it were not the vacuum breaker it could be some compression that has not fully sealed and discovering this might be a challenge.
Can you figure out how quickly the heating element is switching on after the pressure/temperature was reached? I do remember timing this with my old HX machine and I was happy to see that I could get several minutes between each on/off periods. If yours is around 20-30 seconds this might indicate a leak as your boiler is very well insulated.
Good luck.

MediumRoastSteam

I used to have a La Pavoni professional where the nut which attached the steam assembly to the boiler of the machine was slightly loose. You couldn’t see any signs of steam with the naked eye, apart from the fact the pressure was clicking on/off far too frequently - at the time I didn’t know about the dental mirror trick! Eventually I bought some angled socket adaptors, gave it a little nip up and all was well again.

With the Bianca I would have no idea of the cycling frequency, nor how I could detect it, specially as it is controlled by a PID rather than an old school pressure stat.

Good luck and I hope you figure it out what’s going on (if anything at all) soon.

Keep us posted.

rivergo1d

Well after a Royal Mail induced coffee famine, I finally fired up Bianca again today. There doesn’t seem to be any detectable level of steam entering the drip tray once up to temperature, even with the dental mirror, and the mirror also failed to pick up steam around the vacuum breaker.

The hissing is really barely detectable - I only noticed it because the covers were off and I’d just dealt with a more major leak. The boiler is powered on perhaps every 10-20 seconds, but often only for a split second. The rate of pressure drop once off is quite slow, but I’ll have to benchmark it against another machine if I see one in the flesh.

If there is a problem, it’s extremely minor so I’m still inclined to leave it alone until I can compare with another machine, rather than risk overtightening something attached directly to the boiler.

Thanks everyone for your valuable help.