Post By AlecinOz
Vibiemme Junior - intermittent pump/sensor issue
Apologies if the terms I use are not correct as I'm not very technical when it comes to coffee machines.
When I turn my VBM Jr HX (5 years old) on, I usually hear a click which I assume is some sort of sensor to detect how much water is in the boiler? Very shortly after I hear the loud sound of water being pumped into the boiler (again I'm assuming) to fill it. If it is full from the last use, for eg I extracted some water out of the hot water wand which then causes it to refill fully, then I know the next time I turn it on, the boiler is full so it won't have to go through that process. But that is a rare occurrence so 99% of the time, when I turn the machine on, it does pump some water into the boiler.
Every now and again, I would turn my machine on and I would hear the click but not the sound of the pump filling the boiler. I wait a few minutes but it still doesn't pump. I know in this case if I try to make a coffee and steam some milk, I will usually run out of water halfway through so I try to dispense some water out of the hot water wand to empty the boiler and trigger it to re-fill the boiler, but it doesn't happen. After a few minutes, it beeps which I see as a warning so I turn the machine off.
In most cases, I come back a few hours later, turn the machine on and it starts working again. ie I hear the loud sound of the pump filling the boiler and it works fine. But lately this issue has been sticking around for 48hrs or so, before it starts working again. Even when it does start working again, there is a long delay from the usual clicking sound, to the sound of the pump. It is usually fairly instant (perhaps one second delay) but now it's about 7-10 seconds between the click and the sound of the pump.
Has anyone had this issue before? Would anyone know what the problem is? As usual, this issue pops up when I need the machine most and is very intermittent so it's been frustrating. I appreciate any suggestions or workarounds until I can get my machine to a technician. Thanks.
Hi Pokerstar, I can't offer any technical advice, but do have the same machine. I beleive the pump activating at turn on is a 'self check' so completely normal, mine does it every time.
In an effort to pinpoint your problem, what happens when you lift the water reservoir? The low water light should come on and the machine should shut off to prevent the boiler running dry, another built in self preservation feature. If that functions properly, and there is enough water in the reservoir, it is probably a boiler/water level sensor giving you grief.
I think the pump activating at turn on is a result of the circuit that prevents nuisance switching: once the pump triggers it will stay on for a few seconds: similar to the way your windscreen wipers stay on for a full cycle even if you only run them on for a couple of seconds.
The click is probably the pump relay pulling in, the pump should start staight away.
I don't know what your fault is exactly but I've said before the autofill cicuit on these machines is poorly implemented: one of the wires sits right on top of the boiler and the insulation gets cooked.
hi coffee_mum, I will try this and get back to you with results.
Originally Posted by coffee_mum
Hi Lyrebird. Thanks for the suggestion. Is this something I can inspect myself? I've never opened the machine up before but if there are some instructions somewhere, I could probably give it a shot if it is not hard.
Originally Posted by Lyrebird
Have found over the years, that this is mainly due to an inadequate hysteresis adjustment in the controller, when it does occur.
If you're not au fait with electronics black boxes then you may have to find a Tech. who love his coffee, and can help you out for the cost of a few free superb coffees...
The relay clicking and then the pump not starting may indicate that the relay has had it but hopefully nothing more serious...
Bit of extra info. This morning I turned it on and tested it as usual. Same deal, except the alarm didn't go off and I could hear some water boiling which was unusual, then the steam gauge went to full. I was observing very closely because I thought if the element was heating up with no water in it, it might damage the machine but it seemed to be functioning normally. I lifted the water lever to see if any water would come through the grouphead but only a few cold drops came out. I then dispensed some water from the hot water wand and nearly a full large cup came out before the boiler was empty and then we were back at square one where it's not able to pump water into the boiler. I think this might be relevant because it means every time I test it, a small amount of water if actually making it to the boiler? After testing several times over 3-4 days, it has managed to fill the boiler to an acceptable level.
If it stays broken like this, it's a good thing for me because I can take it to a repairer and they can see the problem. When I took it for a service last year, I did mention this issue but they couldn't fix anything because it was working fine at the time. If it starts semi-working again, I may need a real technician. Does anyone know anyone in Perth who would have the skills and the knowledge to be able to fix something like this? There's not many places here, the bigger ones focus mainly on commercial machines.
I'm close to buying a HX machine, likely a new VBMJr, to replace my RSilvia V3. I see a lot of threads describing issues with much older VBMJrs, but how are the latest models holding up? I'm getting mixed messages on build quality, boiler issues etc. How would it compare to a new Diadema Junior Plus or other HX machines in this price bracket?
Seems PokerStar is having issues with one of the water level sensors. In not sure how the logic of these works. (Will search about them later)
After more research on home machines, and some feedback from Jetblack Espresso, I'm going with the Profitec Pro500 PID.
Just an update, I don't have it back yet but the cause was apparently the vibration pump going. These tend to last for 5-7 years, fairly simple replacement. So it's not a disaster, which is good.