Vaillant boiler error F 28

''F.28'' error correction on Vaillant water heater

[XofHope]

Thank you so much for the very clear explanation!

[tomstephens]

Absolute legend!! My missus is starting a new job tomorrow and was fuming she wasn't going to be able to have a shower. Many thanks

[schmutz]

use a brass brush for the elektrodes. to be honest just pushing the button should be enough for f28

[AShahabov]

The Vaillant boiler has started to periodically turn off with an F.28 error. It turns off about 4-5 times a day and needs to be restarted. It cannot ignite the flame on the first attempt, only on the second or third attempt. I called a technician, and he said that the pressure is below normal. I understand that he was referring to the water pressure. He did something and said that it should work now, but the boiler continues to turn off. However, the boiler does not turn off at night and works all night. Can you please suggest what it could be? What should I ask the technician to pay attention to during his next visit?

[antoniom]

For some reason after I press the button either short or longer, nothing happens. The boiler doesn't restart. Still F28 and red light