radiators

My Pegler TRV has a * frost setting and below that a 0 postive off. It also had separate small plastic screw on caps (for painting etc) though I found I had to tighten them more than I thought (I had to ignore my concern about stripping the soft plastic thread and tighten it a lot before it stopped dripping!). The other annoying thing was the compression coupling to the radiator was so close to the plastic cap that it would clip it when tightening. The TRV head didn't have that problem though.

Not sure about Danfoss ones though.

Thanks. I should have made it clear it's the rad that's leaking - rusted through, probably. It's only in the hall so if I can isolate it there's no rush for a plumber (I'm king of the cross-threaders so I stay away from thsi stuff normally). I assumed turning the Danfoss right down would shut it but it hasn't - or maybe it's stuck. I'm _pretty_ sure I closed the stop valve at the other end! The data sheets on their site seem to imply I can take the thermo body off and have a go at the real valve stem, so I may try that.

You need the positive shutoff cap thats supplied with the TRV. It replaces the thermo head. Its like a plastic bottle top. However, most people lose these after a few years or they chuck them away when TRV was first installed because they didn't know what they were for....