It's a relatively straight forward job..basic plumbing and common sense ..turn off water and drain system before you start !(you don't mention what model you have?) .I have just replaced mine as I had central heating but no domestic hot water ...would work if I pushed the contact on the micro switch (located on the left rear of the servo valve) with my finger . I bought a BNIB replacement part off of e-bay for 50pence (bargain!!!!) once it had arrived I had the boiler working like a charm within 2 hours. (I am not a plumber btw)
leo, April 2010
