Bosch Greenstar Combi 151 Problems [9 Easy Fixes]

When it comes to dealing with the Bosch Greenstar Combi 151 problems, there are quite a few issues to deal with. The most common issues that users encounter with this boiler are overheating, faulty relief valve, banging noises, and damaged thermostat.

The list goes longer with problems such as improper gas flow, dropping pressure, automatically shutting off, no water coming out, and water leakage. In this guide, we have shortlisted all the problems and their appropriate solutions for you. Continue reading this Bosch Greenstar Combi 151 troubleshooting guide to know about the issues and fixes in detail!

Bosch Greenstar Combi 151 Problems [9 Easy Fixes]

Here, we will discuss each and every problem of the Bosch Greenstar Combi 151 along with their solutions.

Note: You can also read Crown Boiler troubleshooting guide.

1. Overheating

A common problem with the Bosch Greenstar Combi 151 is overheating. Dirt, debris, and other water impurities accumulate inside the heating chamber over time. This accumulation of dirt often causes the chamber to overheat, resulting in the water heating up more than the set temperature.

How To Fix It

To solve the Bosch Greenstar Combi 151 overheating issue, turn off the boiler and wait for the water to cool down completely. Check the heating chamber of the boiler and clean it properly to remove all the dirt, debris, and so on. Maintain a proper cleaning schedule on a regular basis.

2. Faulty Relief Valve

A faulty relief valve often turns out to be an issue with the Bosch Greenstar Combi 151 boiler. When the pressure relief valve connected to the boiler is faulty or damaged in any way, the valve breaks causing water to leak out of the boiler. This not only results in a flood around the water heater but can also be dangerous if the water comes in contact with any electrical appliance.

How To Fix It

Unplug the water heater from the connection and allow the water to drop to its normal temperature. Empty the heater chamber by draining all the water and examining the pressure relief valve properly. Repair the relief valve to the boiler and make sure that it is placed perfectly.

Turn the water heater on and fill the chamber. Wait for the water to heat up properly to ensure that the relief valve is working properly.

3. Irregular Noises

The Bosch Greenstar Combi 151 noise issue typically occurs when there is a problem with the thermostat or the temperature setting. Dropping pressure and an unclean boiler chamber also contribute to the problem.

How To Fix It

The solutions to the Bosch Greenstar Combi 151 making noises are:

  • Examine the thermostat properly and make sure that it is working properly. If you encounter any damage or faults in the thermostat, repair or replace the thermostat and adjust the temperature setting to the right temperature.
  • Check the pressure to the heater and make sure that it is working properly. Replace the pressure gauge and ensure that there are no leaks anywhere.
  • Open the boiler chamber and clean it properly. Remove all traces of dirt and debris, and make sure that you maintain a regular cleaning schedule.

Tip: Make sure that you disconnect the water heater properly and let the water return to its normal temperature before you conduct the examination and cleaning.

4. Faulty Thermostat

The Bosch Greenstar Combi 151 thermostat not working is a common problem but requires immediate attention. If the thermostat is damaged in any way, then the boiler won’t hold temperature and the water will not heat up.

How To Fix It

To fix the issue of the Bosch Greenstar Combi 151 not heating up, you need to examine the thermostat connected to the heater. Turn off the heater and allow all the water to drain once it cools down. Properly check the thermostat to locate any faulty or broken parts. Repair or replace the thermostat and turn on the heater. Set the temperature to the right setting and check whether the water heats up properly or not.

5. Improper Gas Flow

Another common problem that users encounter with the Bosch Greenstar Combi 151 is improper gas flow. This issue arises when the boiler does not get enough gas to heat up the water. Improper gas flow typically occurs when the gas pipes are blocked or the gas valve is turned off.

How To Fix It

The ways of solving the Bosch Greenstar Combi 151 not getting gas are:

  • Examine the gas pipes connected to the boiler and make sure that they are not clogged. Clean the pipes properly and regularly as dust, dirt, and so on accumulate in the pipes over time.
  • Check the gas valve properly and make sure that it is turned on. Make sure that you turn off the main connection to the heater before doing so.

6. Not Turning On

There are often instances when the Bosch Greenstar Combi 151 doesn’t turn on. This typically happens due to a damaged control board or a faulty power outlet.

How To Fix It

Solving the issue of Bosch Greenstar Combi 151 not turning on is quite easy. Check the control board of the heater and make sure that it is properly working. Repair or replace the control panel if you notice any problems or damage.

Unplug the heater from its power outlet and plug it into another working outlet to make sure that the heater is working properly.

7. Improper Water Flow

The Bosch Greenstar Combi 151 not getting water issue occurs due to a few reasons, including clogged water pipes. Another reason why this occurs is that the water valve is turned off, preventing water from flowing properly. 

How To Fix It

Clean the water pipes and remove all traces of dirt, debris, and impurities from the pipes. Check the water valve and make sure that it is turned on properly. Do not forget to turn off the water and the water valve before cleaning the pipes. Maintain a cleaning schedule on a regular basis to prevent the pipes from getting blocked.

8. Automatically Shutting Off

Thermostat issues and loose wiring result in the Bosch Greenstar Combi 151 turning off automatically after a few minutes. On top of that, low gas pressure is also responsible for this issue.

How To Fix It

  • Examine the thermostat of the heater and make sure that it is functioning properly. Replace and repair the thermostat and adjust the temperature to the right setting.
  • Turn off the heater and open the control panel. Check the wires and make sure that they are secured. Fix the wires in places with the help of the Bosch Greenstar Combi 151 manual.
  • Measure the pressure of the heater to ensure that it is working at the right setting. If the gas pressure is low, turn the heater off and drain all the water. Repair the gas valve, clean the gas pipes properly and ensure that there are no gas leakages. Turn the heater back on and keep an eye on the gas pressure level.

9. Leaked Air Vent

Last but not least, leakage in the air vent results in the Bosch Greenstar Combi 151 not working properly. The leaks cause the gas to escape through the vents, preventing it from reaching the boiler and heating up the water.

How To Fix It

Turn off the boiler and let it cool down completely. Examine the air vents and pipes connected to the boiler. Repair the leakage or replace the pipes to ensure that there are no leaks for the gas to escape. Turn on the heater and make sure that the heater is working properly.

FAQs:

Can I Fix My Bosch Greenstar Combi 151 On My Own?

Yes, you can fix your Bosch Greenstar Combi 151 on your own. However, we suggest taking help from a professional if you cannot identify or solve the issue.

How Long Does A Bosch Greenstar Combi 151 Last?

A Bosch Greenstar Combi 151 lasts for at least 10 to 15 years. The heater will last longer if it is maintained and cleaned on a regular basis.

How to properly maintain a Bosch Greenstar Combi 151?

Repair and replace the parts of the Bosch Greenstar Combi 151 when necessary. Clean the pipes and heating chamber regularly to avoid the accumulation of dirt and ensure proper performance.

Conclusion

You are now aware of all the Bosch Greenstar Combi 151 problems that you might possibly encounter. Whenever you encounter any trouble with the heater, use our guide to identify and solve the issue easily. Take advice from a professional in case you are unable to identify or solve the problem.

If you have any questions or queries about the Bosch Greenstar Combi 151 boiler, leave a comment in the box below. We will get back to you as early as possible.

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