Vokera Combi Boiler?

We have hot water, but no heating. The boiler has 3 green lights. It says purge cycle, we phoned Vokera and they told us to lower the pressure and bleed the radiators and we did that, but pressure has not dropped. British Gas will not deal with Vokera boilers and there are no engineers to be had currently, can someone help as we're freezing. Thanks