Our Combi Highflow 400, was recently repaired by Bosch engineers. They were extremely professional and replaced various faulty parts (pressure vessel, thermostat) and left it working fine.
The next morning the boiler failed to fire for CH, but HW was fine. The pump was running, and if CH thermostat turned up, it would fire for about 5 seconds and then die down again.
As we were going away for a few days, I turned the whole lot off.
When we came back it was fine again.
WB engineer came anyway, and suggested it was an airlock in the boiler, which had dissipated while it was turned off.
Three days later, it has happened again.
WB engineer coming tomorrow.
If it was air in the boiler that was introduced during the original repair, why has it happened again?
How can I get rid of it for good, if I have bled all the rads?
Thanks in anticipation.
Dave
The next morning the boiler failed to fire for CH, but HW was fine. The pump was running, and if CH thermostat turned up, it would fire for about 5 seconds and then die down again.
As we were going away for a few days, I turned the whole lot off.
When we came back it was fine again.
WB engineer came anyway, and suggested it was an airlock in the boiler, which had dissipated while it was turned off.
Three days later, it has happened again.
WB engineer coming tomorrow.
If it was air in the boiler that was introduced during the original repair, why has it happened again?
How can I get rid of it for good, if I have bled all the rads?
Thanks in anticipation.
Dave