I have a Drayton TRV4 which is stuck on heat setting 2. I cannot turn the control knob to increase or decrease the setting. How do I remove the valve to apply WD40 to the body without flooding the place?
there will be a knurled nut directly below trv head, you need to loosen that to take the head off. you can buy just a head for these as far as i know for aroung £10 in case you can't get it loose.