Steam boiler issue Mini Vivaldi II

[toughbean]

Hi all,

Recently I have had an issue with the steam boiler of my Mini V2 (water tank version)

When I turn on the steam boiler, I can hear a hising sound while it is heating and also when the boiler reaches its temperature (red led stop blinking)

After reading another topic; I checked 3 areas:

- on top of the boiler: vacuum break valve
- down the boiler:the drain plug
- behind the water tank: over pressure safety valve

It appears that when the boiler is heating, a drop of steam exits from the vacuum valve once or twice. There is a tiny metal piece that moves up and down when the boiler is cooled. This piece remains up when it is hot

Then, when the boiler is hot, there is a leak of both steam and water from the drain plug that falls inside the water tank. Also the plug is rusty.

Another thing is the steam boiler pressure gauge reads 0 bars

When I use the steam knob, it seems to work ok, and the hot water as well

With the information I gathered from here it seems the vacuum valve is working properly. Regarding the drain plug, Endo wrote in another topic that the nut was welded to the boiler. Maybe it explains why I cannot find the parts in the catalog. I tried to tighten it with a wrench but no success.

So what I would like to know is am I good to buy a new boiler ? What can I do with the pressure gauge ?

Thank you for your help

[chas]

There is a faulty spring inside the valve at the tank that is a known issue. CCS says that LaSpaziale refuses to acknowledge that the part is a problem so CCS is sourcing stainless steel replacements here in the US and putting this part in all new machines before shipment. Contact their tech support and describe the problem. I have little doubt that they will drop a new spring in the mail for you.

[bgosselin]

I have problem with my steam boiler also. To be honest I've been having problem for at least a year. I changed everything. Security steam valve, temp gage. Release valve on top.

My machine is program to start 35 minutes before I wake up. When I'm up the steam gage is at the limit of the red zone but not pass it.

Tonight I open the top and start the machine. My steam boiler pressure move up to 2.5 bar. Way pass red zone. I start the steam wand and got it down to 1 bar. After that it got back up were it is usually. 1.35 bar or so. Can someone explain to me why it doesn't stop heating when it's first turn on but work ok after?

Thanks!

[chas]

I assume you are still under the new machine 2-year warranty and all the parts you have replaced were provided free by Chris Coffee? Do their techs not have any idea what is going on either?

It seems like this has to be a consequence of one of three high level issues:

1) the steam boiler pressure gauge is giving a false high reading. However, you have replaced the meter and nothing changed, correct?
2) the steam boiler heater is not shutting off when it should causing the pressure to overshoot the correct target. The largest likelihood for this issue is a bad temperature sensor, but if so, then the issue should happen a lot more often.
3) the steam boiler heater is shutting off at the correct temperature, but this is causing a higher pressure than normal.The most likely cause for this is that the water level in the boiler is too high. Have you ensured that your water level sensor is pushed all the way down to the top of your boiler. When you have this over pressure situation and you open the steam wand, do you actually get good steam or is it mostly water?

One explanation of how a situation of too much water in the boiler could happen, but only when the S1 is first turned on, would be if the solenoid valve used to fill the boiler is not closing all the way. This might allow a tiny trickle of water to enter the boiler overnight so that it is only overfilled when first turned on.

The problem with this theory is 1) I have never heard of anyone having this problem before 2) If you have a Mini there is no water pressure in the machine when the pump isn't running so it can't happen. I think this issue would be limited to plumbed S1s only.

[mr.sly1]

Hi all thanks for all the info on this site - this is my first post. I share the steam boiler overheating issue. On my 2004 second hand vii the gauge is going way into the red. There is only one gauge on my model. I've just acquired it in the UK for a reasonable price and hoping I can get it going. So, based on the useful posts here I've been trying to work out if it's the temp sensor, the gauge or something else, eg triac. I put the temp sensor in hot water and compared the resistance with the group sensor, it seemed to behave the same, but I know little about electronics. The gauge reads zero when cold, and the steam boiler is turn off and on-able with the boiler switch. The boiler light stops flashing and stays on solid after warm up and then the gauge starts to rise. I haven't let it get to the point where then over pressure valve kicks in as I'm a bit nervous of the high pressure. The water probe seems clean enough and it is far enough down into the boiler. Any ideas as to what I can do next? Previously I only fixed my Gaggia classic which was somewhat simpler...should I just start taking it apart and cleaning everything, solenoids etc?

[chas]

Does the steam pressure eventually stabilize or does it just keep going up? If it stabilizes somewhere in the red, how high does it go?

[mr.sly1]

It got to half way through the red section and was still rising when I switched it off. Not knowing the state of the machine or the over pressure valve I was scared to leave it to go higher, however I guess the OP will leak eventually or an alarm will trigger? Maybe I need to give it a bit longer

[chas]

It sounds suspicious that the steam boiler triac is stuck on. The S1 will alarm when that happens. However, the steam boiler has to get up to 140C before that happens which would probably just about peg the meter in the red. It sounds like you've been shutting down before it gets that far.

There are two identical triac boards. If you pull out the drip tray and them remove that L-shaped chrome plate on the right side behind the tray (1 screw) you can see both boards just behind that chrome plate. The one nearest the front is for the steam boiler and the one behind it is for the group boiler. I would recommend that you swap them. If the board has gone bad now the steam boiler will work just fine but the group boiler will go past your set temp and keep on going. If that happens you have clearly identified the culprit and you can order a new triac board. Here they run about 40USD.

On the other hand, if the steam boiler still exhibits the same issue and the group boiler still works fine then both triac boards are OK and there is no need to swap them back. Should this be the case then that pretty much leaves the temperature probe as the culprit. Most V2 have identical temp probes for both boilers. Assuming yours does, you could try swapping them between boilers to see if that is the issue.

[mr.sly1]

Thanks chas I will try that. Presumably I swap the 2 brown mains leads and the smaller bi-coloured lead on each board?
Incidentally, when I tested it just now before having swapped, the over pressure started venting around 2 bar. In taking it off and fiddling with it I seem to have adjusted the point at which it vents. There is a brass collar which seems to change the height at which the central pin sits.

Also taking the triac boards out I notice one is dated 2004 and the other 2009, I guess one was replaced already.

Again, thanks for the advice

[chas]

Which one had the newer date, the front one or the back one?

[mr.sly1]

My mistake, they are both 2009. After swapping, the group boiler remained steadily at the 95 degree point and the steam boiler got to about 1 bar and then the overpressure valve starting leaking again. I must have done something to it when I removed it. But I suspect that since the group boiler didn't overheat (it was on for a good 10 mins), the triac is ok, which means we are back to the temperature probe. In which case I may go with your suggestion to swap them and see what happens. And I think I'll order a new over pressure valve since it seems to be inconsistent. Does all that sound sensible?

[mr.sly1]

ok latest update, I borrowed the pressure relief valve from my ecm giotto classic to resolve that issue.

After disconnecting the steam boiler temp probe and checking the connections and tweaking all the electrical joints the gauge now rises to 1.7 bar (half way through the red section) but now stabilises. The cycling of the steam boiler seems normal from that point, but now the pressure is constantly around 1.6-1.8.

Does this mean I should still order a new temp probe? I'd better also order a new pressure relief valve or the giotto will not be happy...

[chas]

When the Vacuum Breaker valve on steam boiler won't close all the way, it can often be rejuvenated by a long soak in hot vinegar. However, I have never heard of anyone rejuvenating an Over Pressure Valve this way so buying a new one sounds like a great idea.

Based on what you tried with the temp sensor via unplugging, cleaning, and replugging the sensor, a new sensor may or may not fix things for you. If it doesn't, it never hurts to have a spare. It takes very little extra resistance in the wiring path to change what the controller board perceives the boiler temperature to be. So it is possible that the remainder of your problem is still corrosion somewhere in the sensor's wiring connectors.

Worst case running with the pressure at 1.6-1.7 rather than 1.3ish won't really hurt anything. It's not high enough to pop the overpressure valve or trigger an alarm. You'll just have stronger steam pressure.

[goodboyr]

Chas. Wouldn't extra resistance cause the detector to read falsely high, thus making the controlled boiler pressure lower than normal?

[chas]

Bob, you caught me. They do make temperature sensors with negative thermal coefficients but this isn't one of them. It is possible that a small amount of moisture has gotten inside so replacement is th best option

[goodboyr]

No worries, Chas. As you know, unfortunately I've become quite an expert on temperature sensors......
All of the many failures I have experienced on my Dream(s) have been what would appear to be short circuits in the detectors and that failure mode would cause a high resulting controlled temperature and thus pressure. I know the Dream sensors are PT1000 RTD's. Not sure what the s1 mini's have but my suspicion is the same.

[chas]

Resistance vs Temp of S1 Temp Sensors

PT1000 RTD Temp Sensor Chart.jpg (133.56 KiB) Viewed 25512 times

[mr.sly1]

thanks for the info on the temp probe. The new one arrived today, I popped it in and also the new pressure relief valve. So imagine my disappointment when it once again climbed into the red, levelling out at about 1.7bar. When it gets to that pressure I hear a slight hissing (as if one of the connections on top of the boiler is loose) from the steam boiler, but once it drops back to around 1.5 the hissing stops). I'm going to check all the seals and add teflon tape if necessary.

But I am now determined to get to the bottom of the high pressure. What should I rule out? Probe, triac for sure. Could the gauge be giving a bad reading? It certainly goes back to zero when cold. It's not like the machine is unusable - as you say Chas - it's not like the gauge is pegged or anything.

[chas]

Are you sure that the Vacuum Breaker Valve (VBV) is sealing well when the boiler comes up to temp? This is the usual reason for hissing noises when the boiler comes up to temp. Sometimes you can press on the button on top of the valve momentarily, then let it pop back up, and it will reseal. Since a bit of high pressure steam will blast out when you do this, use some utensil to push it down so that all your body parts are a reasonable distance away. If it still doesn't seal, then remove it (from a cold machine) and soak it in hot vinegar for a few hours. And if that doesn't work, buy a new VBV.

Of course, it could also be that one of those new parts needs a wrap or two of teflon as you noted. The only other source I can think of is something that happened on my first S1 which no one else has ever reported. I tracked down hissing from the edge of the lid on top of the boiler and had to tighten all the lid screws ~1/8 - 1/4 of a turn.

[mr.sly1]

Thanks for the reply. I've just checked and it appeared to be the temp probe bolt hissing which has a small white plastic washer underneath which was not present on the new bolt, so I took the one off the old bolt. All seems fine apart from the slightly high pressure...

[chas]

The only failure mode I have seen on the pressure gauge is higher pressure caused by not going down to zero when cold, but you've already eliminated that possibility That usually happens when the machine has been jarred in shipment. I suppose that the gauge could also fail by not registering at all. Other than that I've never heard of one failing and doing what you are seeing.

The only other issue I can thing of is getting air in the capillary tube between the boiler and the gauge, but I am not sure what the impact of that would be on the reading.

[mr.sly1]

I'm still getting the high pressure in the steam boiler and now I've got restricted flow from the group head as well. Could they be related?

[chas]

The water flow path is only common between the two boilers until you get to the output of the pump. From that point on separate tubing paths and separate solenoid valves control the flow. Normally higher steam boiler pressure and low group flow are two different issues. If there is a problem with pulling enough water out of the reservoir to feed the group boiler I would think you'd probably have trouble pulling much hot water as well. If you can pull 8oz of hot water several times in a row (waiting for the pump to stop running after pull) and you have no issues and the pump doesn't seem to run excessively long in refilling the boiler, then it is probably not an issue common to both boilers.

Otherwise, for the group flow issue, the first thing to try is a good backflush with cafiza or equivalent product. If the first flush doesn't help, I'd try a second time before moving to the next step. The next most likely culprit which is pretty easy to check is the group solenoid valve. If you aren't sure where it is or what it looks like, check picture #4 on this page:http://www.s1cafe.com/s1v1/S1Photos.php the part labelled "A". You will need to unscrew the nut on the left side that is also part of the 3-way copper pipe. With that removed you can just slide the entire solenoid assembly left to remove it. Then you can access the inner part of the valve to check for mineral deposits and other obstructions,

[goodboyr]

I think the flowmeter could be restricted with debris or melted vanes as well.

[mr.sly1]

Just an update - just got my machine back after finally giving up on the steam overpressure issue and sending it to a coffee machine engineer in London. He tried all the things I'd tried (with this forum's help - thanks) and then concluded the 'motherboard' was at fault, which he reckoned was gonna cost around £200, plus a long wait to get the part, plus fitting, etc. That seemed a bit much since the machine was only £260 on ebay. So instead he suggested fitting a steam switch to regulate the steam pressure - with an adjustable screw on the top. He charged me £60 for this, plus another £60 for labour and various little components he had replaced (actually he'd done quite a thorough check - replaced the water probe which had a slight hissing leak, replaced a thermostat, replaced a couple of electrical components - not sure what they were). He's done a bit of plumbing and electrics to fit the steam switch (a tee on the side of the steam boiler with a copper pipe to accommodate it). I haven't worked out how to attach a picture to this post yet but will try shortly. Anyway, at the moment it's set to 1.1bar and it's still got plenty of oomph. The guy didn't speak much English (or me Italian) and he tried to explain that the boilers were only working independently, not at the same time, but when I got home I realised it was just set to ECON mode. So I've set it back to normal mode and it seems fine. No overpressure, the switch seems to have removed the problem. Not quite was I was expecting, but hey.

To summarise, the steam pressure is now normal (and adjustable with a screwdriver!). When I dispense water through the group I still get a strange water pressure noise (like air in central heating pipes or something) but once it hits coffee it goes quiet. I've read a few threads on this forum about this sound and tried a few things (eg taking apart flowmeter - seems fine). It's a sort of sucking whistling sort of noise - again if I learn how to upload a video I will post. But it works - I actually drank coffee from it this morning and it tasted good. It's progress. Now I will try to learn how to get decent microfoam with the 3 hole tip...

[chas]

The noise you're hearing when you start running the group is normal. I've had all three models and they all do it. If it really bothers you turn up the radio while pulling a shot.