I have a Domus HRX2 MVHR that I installed in 2018. It would appear that one of the fans has started to fail and although it is not noticeable during the day, during the night it is audible and makes getting back to sleep difficult. I have been in touch with Domus and they have told me that the fans for this unit are no longer available however the fans from the HXR2D are mechanically the same - different connector (I'm a retired electrician so this isn't a problem).
The parts are SPR