after the engineer changed the 3 way valve which is the normal solution, as confirmed by phone to baxi, I opened the back cover where the grub shrews go and found that it had carbon deposits on the shaft, causing a jam. I cleaned the carbon of and think this will fix the problem, the carbon deposits originates from the material that is covering the brass end

geordie, April 2012

i believe the reason why nobody takes the 3 way valve apart is that it takes you 5 minutes to unloosen, 5 minutes to clean the shaft. But because they can charge 180 to 200 pound a repair, is this the reason why it has not been done. 1 engineer said it is because we live in a throw away society. And by cleaning it the fault my occur and ofcourse there is a little rubber washer in the back of the valve which might be the problem.

geordie, April 2012