📹 Bezzera Matrix MN: Machine Leaking

Learn what to do when a Bezzera Matrix MN espresso machine is leaking.

Is coffee coming up and over the portafilter?

• Replace the group gasket by following the instructions listed in the document attached at the end of this article titled "Replacing The Group Gasket On Your E61 Machine."

Is the leak coming from the lever arm of the machine?

• There are 2 O-rings in the lever of the machine. One or both of them may have blown out. You can take apart the lever, and check to see if they are worn. If they seem to be OK, you can lubricate them and see if that resolves the leak. If they are destroyed, they are also easy to replace and very cheap.

Is it steaming from above the machine through the vents on top?

• The vacuum breaker is connected to a hose that goes into a plastic “T” connector that attaches to the front discharge of the machine. With age and being subjected to varying heat, this “T” connector can become brittle and break. If that happens, then you will be able to see steam coming out of the top of the machine, as the vacuum breaker is closing, or if it is stuck open. If this is the case, the “T” connector will need to be replaced. If the vacuum breaker will not seal, move to the next section.

• Take apart the vacuum breaker and inspect the components, clean all components and remove any buildup or small pieces of debris. Make sure the small O-ring is not broken or too dried out.

  • If cleaning it does not resolve the steam leak, replace the vacuum relief valve.

• Is steam pressure too high? The safety valve will vent when steam pressure exceeds a certain point. Try turning down the steam pressure using the PID controller to see if this prevents the safety valve from going off. If this continues there may be an issue with the relay, control board, or PID controller.

  • If the safety is still leaking, replace the safety valve. Do not take it apart and clean it. Safety valves contain a Teflon diaphragm. On older machines, debris and buildup can form here, this will allow steam to escape when steam pressure is built.

    • NOTE: Under no circumstance do we recommend you remove the copper plug and open the safety valve. This could result in incorrectly adjusting the safety, which will then prevent it from blowing off excess steam like it should. The safety should just be replaced.

How to Clean or Replace a Vacuum Relief Valve

Is the leak or drip coming from the large pipe that comes from behind the group head? (The E61)

• There is one valve above the group head, and two below the group head. One of the two valves may be clogged.

  • Try backflushing the machine by following the instructions listed in our "How to Backflush Your Espresso Machine" article.

  • If backflushing shows no improvement, try doing a group head teardown, and replace any valves or O-rings in the valves, as needed.

How To Clean E61 Brew Group Mushroom, Jet and Top Valve

Is the leak coming from where the two pipes join in the E61?

• If leaking around the fitting or behind the fitting (where the two pipes join), either under pressure or sitting idle, tightening may be required. You do not want to use sealant, as these pipes go into the back of the group head and would be in direct contact with consumable water/coffee. This could also lock the pipes into the back of the group causing damage to the group which would require replacement of the group. With how direct tightening is with those pipes you could end up cross threading into the group head thinking it's just the sealant getting hard as contact with metals is what makes the sealant harden.

  • If after tightening the leak still continues, the pipes may need to be replaced, or the fitting is cross threaded and the E61 group needs replacement. Under this circumstance, both parts may require replacement. 

    • The first part that may require maintenance is one of the plumb lines connected to the back of the E61. If this part is not secure, leaking may happen. This will need to be tightened from the inside of the machine. You may see leaking from the bottom of the machine as well if this is the case. Remove the top of the machine and look towards the front of the machine. These lines will be located on the back of the faceplate, opposite to where the group head is seated. Use an open ended wrench or adjustable wrench to tighten these down.

• Group head maintenance has recently been done on the machine, you may need to make sure the the nut is tightened down all the way. Try turning the nut with a wrench and see if it moves.

Is the leak coming from around the nut where the steam or hot water wand attaches?

• If yes: There is a Teflon ring in there. It is possible that the Teflon ring was bad from the manufacturer. Inside the nut for the steam wand is a small channel that the Teflon ring sits inside. You can undo the nut and inspect the Teflon for damage or to see if it has moved from the channel in which it sits.

Is it dripping or leaking out of the tip of the steam wand?

• Yes. It should leak or drip a little bit after use, and when the machine is first started up. This is normal, and due to condensation in the pipe. It should subside after a few minutes of non use.

• Yes. If a leak like this is present, it may be due to either debris in the valve preventing the gasket to seal, or the gasket itself is worn out and no longer seals. Inside of the valve is a long shaft with a round rubber gasket inserted in the end of it. This rubber has either gotten hard with age and no longer seals properly, or the gasket has been over tightened too much and either is not sealing properly, or has shredded.

Is the leak coming from between the steam tip and the wand?

• If the leak is between the wand and the steam tip, this is most likely due to the rubber O-ring around the steam tip.

Is the leak coming from the safety valve?

• What kind of water are you using?

  • If you are using distilled water, or reverse osmosis, there will not be enough mineral content in the water for the water level probe to send a ground signal, telling the pump to shut off.

• If the pump is still running and water comes out of the safety valve, check that the connector did not come off of the level probe, if it did, reconnect.

• Make sure that the green and yellow ground wire did not come loose from the control board. This usually results in the safety valve spraying like a sprinkler, not just a “leak”.

• Make sure that the wire coming from the autofill going to the board, right next to the ground wire, did not come loose.

• If the safety is still leaking, replace the safety valve. Do not take it apart and clean it. Safety valves contain a Teflon diaphragm. On older machines, debris and buildup can form here, this will allow steam to escape when steam pressure is built.

  • NOTE: Under no circumstance do we recommend you remove the copper plug and open the safety valve. This could result in incorrectly adjusting the safety, which will then prevent it from blowing off excess steam like it should. The safety should just be replaced.

Is the leak coming from the boiler itself?

• Is it leaking from where a valve screws into the boiler?

  • Remove the valve, and clean any remnants of sealant. You can use Teflon tape, Permabond, or Loctite to reseal the valve back into the boiler.

  • Is the leak coming from a weld point on the boiler?

    • The boiler must be replaced.

I cannot find the source of the leak.

• Run the machine to allow it to heat. Some leaks may only be apparent under heat and pressure.
• You can open the machine and send us any photos or videos, so we can determine if we can find the source of the leak.
• Send the machine in for service.

Is the leak coming from the top nut on the group head?

• There is an O-ring that is loose, dirty, or worn out. Take out this mushroom valve, clean any scale or debris, and reseat the valve. All of these parts are separated by Teflon rings. It could just be loose and slightly tightening could stop the leak, but with heat and age it's possible the Teflon is no good. Tightening the bit down more will only further deform the Teflon allowing a leak to still continue, so these should be replaced. If it is still leaking, replace the gasket that separates it from the top of the group head. To access these parts use an open ended wrench or adjustable wrench to remove the smaller top bolt of the E61. This will give you access to the first O-ring and spring assembly. To access further down into this part of the group head use a wrench to remove the large bolt. This will let you access the other O-ring, another spring assembly, and the valve assembly. Inspect all of these components for integrity. Clean any dirty parts and replace any broken parts. Reassemble the group head and see if the leaking is resolved.

• If you’ve recently serviced the group head, it’s possible the nut is just loose. Try tightening it.

Is the leak coming from the bottom of the machine?

• Inspect the plastic reservoir valve socket. If it is cracked, it will need to be replaced.