Central Heating

Vaillant Eco max gas boiler F25 fault, but no apparent leaks

Anonymous user 28/02/2024 - 2.56 PM

In the morning after the system has cooled a dF25 faults keeps showing, I will top up the system with the smallest amount of water it will allow the system to go, what then happens as the water heats the arrows climbs off the dial to almost the red mark. In the morning after the system has been timed to go off overnight the same F25 fault is there, I will repeat the process as before, the dial will go almost to red, runs for the rest of the day until the system is timed out, seems to relate to when the water cools? Your advice would be appreciated Regards Dan