I have a problem with a Heatline solaris, it keeps blowing a fuse, at first it would not fire and I found a dry joint on the PCB I repaired this. Now the problem is it fires and will stay a light with central heating fine. If I demand water it will sometimes blow a fuse. Its always the first fuse on the board after the power cable? I suspected it may have been the 3 way valve/ motor but I have replaced this and still it blows the fuse. Any Ideas