Hi I i'll found some led head light bulbs that work in the voyager at a reasonable cost they are Q1 H7 and H9 cost £12 and cheaper and will not blind other road users and mot friendly have fitted two sets so far with good results you can buy on ebay now.Jeff
Thanks for all your help Nev, feel a bit stupid now, turns out it was trapped wind added a bit more water it had a big 'burp' and hey presto the heaters started warming up.