Bosch fault code B6L515
Fault code B6L515 on a Bosch boiler (including Condens 7000FP) means: Loss of the ionisation signal during operation. Reset the appliance once. If the code comes back, a part is usually faulty. You can check the water pressure and settings yourself; leave work on gas-carrying parts to a certified gas engineer.
After a safety alert (gas, flue gas, combustion), reset no more than once and call in a certified gas engineer. If you smell gas, call your national gas emergency number or 112 immediately.
Cause
Fault code B6L515 on a Bosch boiler indicates: Loss of the ionisation signal during operation.
Fixing fault code B6L515: step by step
- Check that the gas valve at the appliance is open and that other gas appliances, such as the hob, are getting gas.
- Check that the condensate trap under the appliance is filled and clean; a blocked condensate drain can make the boiler lock out.
- Check outside that the air intake and flue are clear (leaves, a nest, ice or snow).
- Reset the appliance once. If the code comes straight back, do not keep resetting it.
- If the fault keeps returning, the ignition or ionisation electrode is usually worn or dirty. It sits in the sealed combustion section: have it replaced by a qualified heating engineer.
Applies to
Bosch Condens 7000FP, 350 L / R, 400 L / R, 500 L / R, Condens 7000F, 100 kW L / R, 150 kW L / R, 200 kW L / R, 300 kW L / R, 75 L / R.
Matching parts
Bosch parts are available from Instalpunt; shipping to EU countries from €12.95 (€16.95 for more distant countries), usually 3–5 working days.
For fault code B6L515, the part involved is usually in the category: electrode.
This message does not point directly to one faulty part. If the code keeps coming back, view the Bosch parts:
Fix it yourself or call an engineer?
Always consult the manual for your appliance and work safely. If in doubt or if the fault comes back, call in a qualified professional. A question about a part? Write to us at info@instalpunt.nl.
Frequently asked questions
What does Bosch boiler fault code B6L515 mean?
Loss of the ionisation signal during operation.
How do I fix fault code B6L515 on a Bosch boiler?
First check the cause described above. Then restart the appliance using the reset button. If the message comes back, a part usually needs replacing or the fault needs to be repaired by a qualified professional.
Which parts do I need for Bosch fault code B6L515?
That depends on the exact cause. In the Bosch parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code B6L515 myself?
You can reset the appliance and check things like the water pressure or settings yourself. Work on gas-carrying parts must be left to a certified gas engineer.
All Bosch boiler faults and codes at a glance →