You can use a pump BUT how and when will you make the pump run ?
This will be the problem for you do it this way as explained below...

1) Run Permanently
If wired to run permanenty, you will dead end the flow.
As most central heating pumps are centrifugal, (they dont create a vacuum)
then thay will run dead ended all day.
You will just waste electricity and the pump will be noisy when dead ended.
Could put it on a time switch ???????

2) Pressure controlled.
You will need a check valve on the pump outlet (one way valve)
The pressure switch is installed AFTER the check valve.
The pressure switch is wired to run the pump on low pressure.
(this may require a relay depending on switch and pump current rating)
The one way check valve stops the pressure going back up the pump
when the pump stops.
When the tap opens, pressure drops, pump switches on.
When the tap is shut, pressure builds, pressure switch turns OFF and
the pump stops. Check valve holds the system pressurized.
There is a draw back with this, if you have very hot water and it cools
in the pipes under pressure, it can cause a vacuum as the temperature falls.
The result is, you may need an expansion cylinder after the check valve
to prevent the pipe from deforming under vacuum and prevent the pipes
from "knocking" when the tap is opened/closed.



Hope that answers your technical issues....