Bezzera Strega/troubleshooting
From Whole Latte Love Support Library
No Crema or Bad Tasting Shots
Typically, issues with crema or the flavor of the shot do not indicate a malfunction of the machine. Instead, this indicates that an adjustment needs to be made in the brewing process or that different beans need to be used.
The following articles review the different variables and offer solutions:
- Tamping The Correct Way and The Effects Of Tamping Pressure
- Grinding Coffee For Espresso
- It is important to use fresh beans, typically beans roasted within the past two weeks are best. Light and medium roasts are best for espresso brewing and richer crema. Storing beans properly is also important, more information can be found here.
If the behavior persists after reviewing these factors then the machine may need to be cleaned. Lack of cleaning can cause burned or bitter flavors, or create flow issues which can result in a weak shot. Navigate to the Cleaning & Maintenance icon above for more information.
Difficulty Frothing
As with brewing, technique is critical to frothing well. Frothing is very sensitive to technique, which has a steep learning curve. If the machine is producing steam then an adjustment to technique may need to be made. The video on the right shows proper frothing technique.
How to Froth and Steam Milk for Latte Art, Cappuccino and More
Many frothing mistakes are common missteps that result in poor or no froth. The video on the right identifies these mistakes and shows how to correct them.
6 Common Milk Frothing Mistakes
It is also important not to overheat your milk. The milk will have the sweetest and most velvety texture between 140-150 F°. As you froth past this point the milk will lose its sweetness, the froth will take on a gummier texture, and eventually the milk will scald and begin to taste burnt. The video on the right explains how to use a frothing thermometer so that the milk is kept within the ideal range.
How To Use a Thermometer to Froth Milk
Flow Issues
The first place to start with any flow issue is cleaning the machine. Before going through these steps please make sure the machine is cleaned according to the Cleaning & Maintenance section above.
No Steam From Wand / No Hot Water From Hot Water Tap
- Check the brew function on the machine and see if water is able to flow through the machine for this function.
- If the brew water is not flowing, either refer to the No Flow At All section of this article
- If the brew water flows but is not hot, refer to the On But Not Heating section of this article.
- If there's no hot water from the hot water tap, check the steam function of the machine. If you are able to draw steam from the steam wand then the steam boiler must be pressurizing and heating.
- If there's no steam from the steam wand, check the hot water function of the machine. If you are able to draw hot water then the steam boiler must be pressurizing and heating, because hot water is expelled from the machine by steam pressure.
- Check the steam gauge of the machine. Does it show pressure? Typical range for the steam gauge should be 1-1.2 Bar.
- If the gauge is within the 1-1.2 Bar range, then the steam wand is likely blocked.
- Remove the tip from the steam wand and test the flow. If flow is restored, then the tip needs to be cleaned and reattached.
- If the flow is still blocked, then there may be a blockage in the steam wand itself. Clean the wand by using a pipe brush that has synthetic or plastic bristles; metal bristles can damage the wand. Then soak the wand in a solution of hot water and backflushing powder for ten minutes. Test flow again.
- If there still isn't flow, then there may be a blockage farther back in the steam circuit. The machine may need to be professionally cleaned to remove the blockage.
How to Diagnose Hot Water and Steam System Obstructions
- If the gauge is not reaching 1-1.2 Bar, but it is pressurizing some, then the steam pressurestat may just need to be adjusted.
- When adjusting the pressurestat, only slight adjustments should be made. Small adjustments will make a large difference in the pressure.
How To Adjust the Pressurestat
- If adjusting the pressurestat the first time did not raise the pressure, try adjusting it a few more times. If the pressure is still not raising after several adjustments then the pressurestat is likely broken and will need to be replaced.
- If the gauge sometimes reaches 1-1.2 Bar, but flicks around a lot or randomly drops to zero, or is always sitting at zero, then the steam boiler is not building pressure for some reason.
- If the machine is spewing a lot of steam from the top as it is heating up, then the vacuum relief valve may be stuck open. This valve is supposed to close once the machine produces enough steam pressure. The video on the right shows how to clean or replace a vacuum relief valve. A different machine is used in the video, but the process will be the same.
Vacuum Relief Tear Down Instructions
- The high limit switch may be tripped. The high limit switch is an internal killswitch which prevents damage to the machine caused by power surges or the machine overheating.
- While the machine is open for resetting the high limit switch, check to make sure the wiring to the pressurestat isn't loose or disconnected. Reconnect the wires and see if the steam circuit pressurizes properly.
- If there weren't any disconnected wires, then the pressurestat will need to be replaced.
Poor Or No Flow From Grouphead
If there is little to no flow from the grouphead then it will need to be taken apart for cleaning.
- Use a flathead screwdriver to pull the shower screen down and off the machine. Looking at the grouphead from below there will be a lip on the shower screen. Gently pry on this lip with the screwdriver from different angles until the shower screen comes off. The group gasket may come off with the screen.
- Use a grouphead brush or an old tooth brush to clean brush down any dirt or coffee residues from the grouphead. Dipping the brush in a solution of hot water and backflushing powder will assist in removing residues.
- Soak the shower screen and filter baskets in a solution of hot water and cafiza. Rinse of the gasket with plain water to remove and grinds or coffee buildup.
- If this does not solve the flow issue then the machine will require professional service.
No Flow At All
If the machine is set to the plumbed mode:
- First try switching to reservoir mode temporarily and see if this resolves the issue. If it does, then the issue is limited to the plumb line and you should go to the next step. Otherwise keep the machine in reservoir mode and skip down to the next section which deals with testing no flow in reservoir mode.
- Return the machine to plumb mode. The next thing to check is to see if we can isolate where the flow issue is occurring for the plumb line. Try putting the plumb line hosing into an external bucket or container filled with water and see if the machine will draw water from this source. If it can't then there may be a blockage somewhere in the plumb line itself.
- If you are able to draw water from the plumb line, then there may be an issue with the plumbing supplying this line.
If the machine is set to use the reservoir:
- If the pump does not sound like it is activating:
- Check to make sure the water tank is filled and the machine isn't indicating that the water tank is empty.
- If the tank is empty refill it.
- If the tank is full, but the machine thinks the water tank is empty then the tank may not be seated correctly. Make sure there isn't anything blocked the tank from sitting flush inside the machine. Use of R/O, distilled, and zero waters will cause this sensor to malfunction, resulting in the machine thinking there is no water causing the pump not to activate.
- Remove the cover of the machine and check for any loose or disconnected wires.
- There may be an issue with the water tank sensor.
- Remove the drip tray from the front and make sure the plumb switch is turned off.
- Remove the reservoir and make sure the float magnet is facing the sensor. Magnet on the float should be facing the back left corner of the tank.
- Check to make sure the wire for the water level sensor isn't loose/disconnected.
- There may be an issue with the pump powering on. Check to make sure the pump doesn't have any loose/disconnected wires.
- Check to make sure the water tank is filled and the machine isn't indicating that the water tank is empty.
- If the pump does sound like it is activating make sure the plumb valve and the plumb switch are both set in the correct position. If they are set in opposite positions then the pump will activate, but water won't be able to come through the machine.
Machine Is Leaking
Between Portafilter & Grouphead
If the grouphead leaks from the space in between the portafilter and the grouphead during brewing then the group gasket is either worn out or out of place. This gasket needs to be replaced typically every six months to a year.
- Use a flathead screwdriver to pull the shower screen down and off the machine. Looking at the grouphead from below there will be a lip on the shower screen. Gently pry on this lip with the screwdriver from different angles until the shower screen comes off. The group gasket may come off with the screen.
- Use a grouphead brush or an old tooth brush to clean brush down any dirt or coffee residues from the grouphead. Dipping the brush in a solution of hot water and backflushing powder will assist in removing residues.
- Soak the shower screen and filter baskets in a solution of hot water and cafiza.
- Once everything is clean insert the shower screen into the group gasket securely.
- Press both the shower screen and gasket into the grouphead together. Then attach the portafilter firmly to secure these components into place.
From Bottom Of Machine
- Check the water tank and drip tray to make sure there are no cracks or breaks where water can escape. Make sure they are properly positioned on the machine.
- Open the machine and check all of the connections to make sure they are securely attached.
- Examine the pump and boiler assemblies to see if there are any cracks in them. If the machine was exposed to subfreezing conditions without being properly drained it can cause these components to crack. These parts will need to be replaced if they are cracked.
- Make sure both the inlet line and the outlet line on the pump are securely connected.
- Check the various valves located on top of the boiler assembly.
- If water is leaking from the relief valves, then the boiler may be overfilling. Distilled, reverse osmosis, and zero water are not compatible with this style of machine as the water level probe depends on minerals in the water to detect its presence. These water types do not contain minerals, and so the machine will continuously fill until it overflows, usually resulting in water leaking from the relief valves.
- If water is leaking from the relief valves even though you are using a water that contains minerals, then you may need to clean the water level probe.
- If the machine is plumbed, then there may be too much pressure at the inlet line. The pressure restrictor may need to be adjusted, or if you do not have a pressure restrictor installed you may need to install one.
- If the valves are leaking directly from where they screw into the boiler, then they may have a broken seal. Try resealing the valves by using white teflon plumbers tape or food safe permabond and screwing them back into the boiler.
- If there are any broken or cracked hoses, or hoses with pinhole leaks, they will need to be replaced.
- If you cannot find the source of the leak, it's possible the water you are seeing is from water spilled when refilling the machine, or from the drip tray being out of position. It is also possible to run the unit with the casing off to help identify the source of the leak; precautions should be taken to protect yourself from any exposed wiring or hot water or steam that comes from the machine if you attempt this.
Steam From Top Of Machine
If there is steam coming from the top of the machine then one of the relief valves is venting steam.
- If the steam is leaking from the machine while it is heating up, with more and more steam coming from the top as the machine heats more, then the steam is coming from the vacuum relief valve.
- The vacuum relief valve is meant to vent steam until a certain amount of pressure has built up in the boiler. It is normal for this valve to vent steam as the machine is heating. Once enough steam pressure is built up in the boiler the valve will pop closed.
- If the machine is fully heated and the vacuum relief valve is still not closing then it may need to be cleaned.
- The video below discusses what these valve components do and how to clean them.
How To Clean or Replace a Vacuum Relief Valve on a Profitec Pro 700 Espresso Machine
- If cleaning the vacuum relief valve has not resolved the issue, then the vacuum relief valve may be broken and will need to be replaced.
- If the steam is leaking from the machine after it is fully heated, then the pressure relief valve may be relieving excess steam pressure.
- The pressurestat may need to be lowered. If the pressure is set too high the relief valve may open.
- The pressure relief may be stuck open.
- If the relief valve is still opening, then either the pressurestat or the relief valve may be broken and will need to be replaced.
- There is a seal in the steam valve that may be worn or dirty and is letting water through. The seal may need to be replaced, or it can also be flipped over and reused.
- The steam tip o-ring is easy to access. Simply unscrew the steam tip and there will be a small o-ring between the tip the wand arm. Inspect this o-ring for damage and clean it.
- The hot water tip is a little more complicated, but still easily accessed and cleaned.
- First unscrew the tip assembly from the wand arm.
- There will be an o-ring between the tip assembly and the wand arm. If the leaking was coming from here, then this o-ring needs to be cleaned and repositioned, or if it is damaged it will need to be replaced.
- If the leaking was coming from farther down on the tip, then the tip will need to be disassembled further to troubleshoot. To disassemble the tip further simply twist the two halves of the tip assembly in opposite directions. Alternatively you can screw the tip back onto the machine and then just unscrew the bottom half of the tip; this will give you a better grip on the tip to unscrew the two halves.
- Once the tip is apart, it will separate into three separate pieces. There will be three metal pieces and another o-ring. Inspect the o-ring for cleanliness and damage. The metal pieces can be soaked in a solution of hot water and backflushing powder to remove any scale buildup on them.
- These instructions apply to both the steam and hot water wands. First remove the wand arm. This can be done by unscrewing the hex shaped nut at the top of the arm. Please note that this assembly is reverse threaded, so you will need to turn the nut clockwise to loosen it.
- Once the wand is removed you may have parts stick to the valve assembly. Do not lose these parts.
- If the leaking was coming from the top of the securing nut, check the white teflon o-ring to make sure it is in clean and in good condition.
- Inspect the tension spring to make sure it is in good condition. The spring should be really firm. If it is easily compressed then it may need to be replaced. The
bottom of the spring will have a metal gasket, which helps the wand pivot on the spring Make sure these parts are clean and reinstall them.
- You will need two open ended wrenches, or adjustable wrenches to tighten this assembly down.
- First remove the top panel and covering of the machine. Put one of the wrenches on the bolt pictured below. The bolt will be towards the front of the machine, opposite to where the valve assembly attaches to the faceplate.
- Place the other wrench on the square shaped steam valve on the front of the machine. Keep this wrench stationary, and then turn the other wrench to tighten the bolt down.
Machine Not Heating Or Powering On
No Power
- Make sure the machine is plugged into an appropriate power source.
- Do not use the machine on a surge protector. This machine has a high power draw, more than a typical kitchen appliance such as a refrigerator or a microwave. Surge protectors are typically not rated to handle the amperage this machine requires.
- Try using the machine on a different outlet, and make sure the machine is the only appliance plugged into that outlet.
- Make sure the power switches are functioning properly and not broken. If the machine isn't powering on try pressing and holding the power button in the on position to see if the machine turns on. If you are able to power the machine on this way then the power switch needs to be replaced.
- If the machine recently had a leak, had water spilled on it, or any other exposure to moisture then the machine may be shorting out. Try letting the machine sit unplugged for 48 hours to make sure there isn't a short caused by moisture.
Brew Not Heating
- Give the machine sufficient time to heat up. A heating time of 20-30 minutes is recommended for prosumer style machines for it to be sufficiently heated for brewing. Make sure the portafilter is attached during heating.
- Make sure the heating indicator is on. If the heating indicator is not on, then the machine will not heat. Typically this light will be off if the machine is out of water or not able to fill the boiler.
|#The pressurestat may be set too low resulting in a lower temperature. Be cautious when adjusting the pressurestat. Setting it too high can cause the machine to overheat, resulting in the pressure relief valve blowing off excess steam.
- The high limit switch may be tripped and needs to be reset.
- The heating element may be broken and may require replacement.
Steam Not Heating
- If the machine is producing steam, but you think it's not producing enough steam, make sure that you are purging the line before frothing. To purge the line simply open the steam knob and let steam come through until it changes from mostly water to mostly steam. When steam leaves the boiler and hits the cold wand it is going to condense back into water. If you do not purge the line it will affect the way the steam wand froths.
- Give the machine sufficient time to heat up. A heating time of 20-30 minutes is recommended for prosumer style machines for it to be sufficiently heated for brewing. Make sure the portafilter is attached during heating.
- Make sure the heating indicator is on. If the heating indicator is not on, then the machine will not heat. Typically this light will be off if the machine is out of water or not able to fill the boiler.
- The pressurestat may be set too low resulting in a lower brew temperature. Be cautious when adjusting the pressurestat. Setting it too high can cause the machine to overheat, resulting in the pressure relief valve blowing off excess steam.
- The high limit switch may be tripped and needs to be reset.
- The heating element may be broken and may require replacement.
On But Not Heating
- If your machine is running off of the reservoir, make sure it is filled with water. Don't use distilled or reverse osmosis water, as the boilers rely on some minerals to detect water level.
- There is a loose, disconnected, or broken wire inside the machine. Remove the top of the machine and inspect the wiring.
- The high limit switch of the machine may have tripped.
- The outlet the machine is plugged into is not rated to handle the power draw of the machine.
- The heating element may have failed and may need to be replaced.
Portafilter Handle Not Fitting On Machine
- On all new machines, the portafilter may or may not fit perpendicular to the machine. This is perfectly normal. This is because the grouphead gasket requires time to wear in before this can happen. As long as you can get the portafilter hand tight onto the machine and brew without leaking, then the machine is operating properly.
- Too much coffee may be dosed into the portafilter. If there is too much coffee in the portafilter, it can press into the shower screen and prevent the portafilter tightening all the way. Reduce the amount of coffee in the portafilter and try again. If you see an indentation from the shower screen in the grounds, then you’ve added too much.
- Check the filter baskets for dings, dents, or any sort of warping. A filter basket that is malformed can prevent the filter basket from sealing up against the group gasket.
- The group gasket has slipped out of place or needs replacing. Please refer to the section of this article which discusses gasket issues for instructions on how to test the gasket or replace it.
