SHowerforce Pump Noisy?

Hi,

I have a SHowerforce Turbo pump fed via a cold water tank and hot water pipe connected in the loft. It is very noisy when started as if there is air in the system for about 30 - 60 seconds. There is a slight improvement when the hot water pipe is run int he bathroom first.
The pump is mounted below the cylinder and has got gradually worse over 5 years. Yesterday it tripped the electric and I was all set to purchase a replacement but I have just tried it again the next day and it is running again, albeit noisy, appreciate any advice..