paulb,
There are a number of components which could have gone wrong, try removing the photocell and make sure it is clean, if this does not solve the problem its time to call in a heating person.
end
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!