All,
my first post here and a newbie. I've been a proud owner of a La Cimbali M20 2-group machine for a couple of years. I bought it in some dis-repair and spent some money with Espresso Plus in Boston to get it to spec. Anyway, I just discovered that the anti-siphon valve leaking. This is the valve above the water mark indicator. Obviously, the water level is full and it is coming out this valve. Espresso plus said "a couple of sensors could have failed". The machine builds pressure indicated by the bars, but the frother only dispenses hot water and not steam. Help - i would like to fix this myself.

RK

rkuppuraj wrote:All,
my first post here and a newbie. I've been a proud owner of a La Cimbali M20 2-group machine for a couple of years. I bought it in some dis-repair and spent some money with Espresso Plus in Boston to get it to spec. Anyway, I just discovered that the anti-siphon valve leaking. This is the valve above the water mark indicator. Obviously, the water level is full and it is coming out this valve. Espresso plus said "a couple of sensors could have failed". The machine builds pressure indicated by the bars, but the frother only dispenses hot water and not steam. Help - i would like to fix this myself.

RK

I am not familiar with your exact machine, and a picture would help enormously. I am assuming from what you posted that you have an older 2 group machine with autofill and a sight glass. If my assumptions are correct the most likely and easiest to deal with problem would be that you have not been treating your water (sufficiently) and as a result you have scaled up the autofill probe in the boiler so that it no longer senses that the water has reached the probe and continues to fill the boiler beyond a reasonable level. Another possibility is that the wire has come off the autofill probe outside of the boiler and that this is having the same result; reattaching the wire would fix this problem if this is what is going on.

If I am correct, then you should unplug your machine and drain the boiler a bit so that you can extract the autofill probe without getting a flow of water coming out that hole when you remove the probe. You will also need to turn off the incoming water before it enters your machine. You can then remove the probe and clean it off, either manually with some sort of abrasive or with descaler/citric acid, or both. You can then reinsert the probe and re-attach the wire to the probe so that the circuit is completed. This will only partially cure your problem because in this case you presumably have a scaled up boiler which you will need to descale, which is a whole other topic.

The vacuum breaker valve, to which I believe you refer, is not intended to stop water from coming out, rather it seals the boiler when the boiler heats up to prevent "false pressure" coming from steam. You won't know whether this valve is still functional until you stop the boiler from over filling and then try to see if it will seal when the boiler is heating up with a proper level of water and steam in it. If the vacuum breaker valve is toast it is a cheap and readily available disposable part you can replace in less than 5 minutes.

Good luck.

ken

Ken,
thanks a lot for the feedback. I am enclosing some pics. The first one is the brass valve that is leaking (it is dry in the pic). I also have a shot of the machine - you are right it is an older 2 group autofill. Is the water level probe the one pictured, above the boiler?

Ravi

rkuppuraj wrote:Ken,
thanks a lot for the feedback. I am enclosing some pics. The first one is the brass valve that is leaking (it is dry in the pic). I also have a shot of the machine - you are right it is an older 2 group autofill. Is the water level probe the one pictured, above the boiler?

Ravi

Hi,

That is the water level probe, and yes, you have taken a picture of the Vaccum Breaker, which is often (erroneously) referred to as the "false pressure valve."

If the probe is all scaled up, and if after cleaning it off the problem goes away, you will have your answer, but will still have to deal with scale in other areas (boiler, heat exchanger, brass tubing).

What kind of water are you using (as regards hardness) and how are you treating it? Even if you used a cation softener it is possible that you could get a fine white powder on the probe which could prevent proper operation of the autofill circuit. If that is the case, than cleaning off the powder might solve the problem entirely.

Good luck and happy new year.

ken

Thanks - leak has stopped! I took out the probe - its tip was brown/dirty. Also took out the vacuum breaker and put it back. Made good espresso. However I noticed that the frother put out more hot water than steam? Not sure if I did not leave it on long enough? Is there another temperature sensor I need to check?

Also, any tips on descaling/cleaning? I have some basic inline filters only now.