Problem: The CH and HW all work fine with no problems and no error codes but there is rattle and vibration from the pump, sounds like pump is shot.
If I drain, refill and vent the system as per the Vaillant manual, using the P0 program to let the pump vent (as it’s a self venting type) there is no noise from the pump and it works fine, put on CH full load again all fine, but as soon as there is a DHW the pump rattles and does not stop even after hot water demand has ended and the CH starts, the only way to stop it is to drain the refill.
Bypass is set to 250mb and pump speed is set to auto
Any ideas? Anything else worth looking or is it as I initially thought that the pump is dead, which seems shocking as it’s only 1 month old, and yes the systems was flushed.
By the way when this is working properly the boiler is wisper quiet.
If I drain, refill and vent the system as per the Vaillant manual, using the P0 program to let the pump vent (as it’s a self venting type) there is no noise from the pump and it works fine, put on CH full load again all fine, but as soon as there is a DHW the pump rattles and does not stop even after hot water demand has ended and the CH starts, the only way to stop it is to drain the refill.
Bypass is set to 250mb and pump speed is set to auto
Any ideas? Anything else worth looking or is it as I initially thought that the pump is dead, which seems shocking as it’s only 1 month old, and yes the systems was flushed.
By the way when this is working properly the boiler is wisper quiet.