I've been told my Potterton Netaheat boiler needs a Sunvic motorised valve complete 3 port valve and have been quoted a price of £155. Does anyone know if this is a reasonable price or would I be cheaper buying the part myself?

Julie Moxey, February 2008

Most sunvic failures are just the actuators which can be repaired cheaply and you do not need to drain the system

www seered co uk, October 2008

you don't need to replace with a sunvic which are not the best better of with a honeywell supply & fit is about £150.

hi-spec plumbing & heating, February 2008

Julie ...I did a search on the Internet (get a part number off the motor portion of the valve and google it) and got a similar valve for £45 and they are not difficult to change if you're ok with electrics. It's just a matter of draining the system to below the valve and swapping electrical wire by wire from the old valve to the junction box. First thing to do is to mechanically disconnect the motor box from the valve by undoing 4 screws and then seeing if you can move the valve with your fingers. If you can, you only need the electrical bit and then you don't even need to drain the system. Usually the motors are unreliable and you can smell them if they are burnt out as mine was.

Spilge, February 2008