Hello My name is Ian ~ I am not on the site constantly so please be patient whilst waiting for responses to you queries
Can you tell me which model you have of back boiler is it ~ 40 45 50 54 ?
No that is the burner unit, if you go to the left side of that you should see a box with a knob on it and what looks like a piece of thick wire coming out of it ~ have you got it?
OK this will be a bit hit and miss without knowing which model it is, can you follow the mains power cable and tell me where it goes to in the boiler ?
OK if I send you a link to a group of installation manuals can you look through them and tell me which model you have got?
Here is the manuals, just see if this covers your model ~ http://www.glow-worm.co.uk/trade/literature/back-boilers/ come back to me if its in that lot, if not there are some more modern ones I have ~ Ian
yes this is the control that sets the temperature of the water
OK sorry had to answer the phone, glad you have sorted it out, now that you have rated me you can come back for further information at any future time free of charge. Have a good evening ~ Ian