Noisy water pump?

Hi - can you recommend a quiet water pump as our exisiting one (salamander?) is so noisy! On the 1st floor in our house the pump (for hot and cold water) supplies the shower in the 1st floor bathroom plus it supplies the water for the hot and cold in the loft conversion bathroom (basin, toilet and shower). We don't mind the noise when the 1st floor shower is used but when we have guests stay in the loft, the noise is unbearable - particularly the on off on off at the basin when brushing teeth for example.

Can you please recommend a quiet pump or is their another solution???