how can i bring the water preasure up in my valliant turbomax combi boiler?

my valliant turbomax has low water preasure and as a result the radiators in my bedrooms are cold up the top and hot at the bottom please could you let me know how to raise the water preasure.
mr Dawson, March 2005


done
You will also need to bleed the radiators, then top up the pressure again. Follow the cold water inlet, and you will see the built in valve (underneath and is part of the boiler), It should hace a key in place but as this is only held in by a rubber O ring it may have fallen out, use a screwdriver to turn it and top up the system.

Dode, December 2005
Some valliants have a built in filler loop system which is a small key on the underneath of the boiler on the right hand side , turn this and the pressure will go up

Steve, March 2005