Sure can....expect the pressure to increase a few psi when the heating is running - this is normal. Keep the pressure at 1.5 bar - best set cold. If the pressure fluctuates, the expansion vessel needs recharging. If the pressure drops, look at the overflow pipe outside. If its been dripping, have the pressure release valve replaced (£10 part). If the pressure is still falling, have the automatic air vent (AAV) replaced. (£8 part).
John, November 2009