LMSC Sorry my fault, coffee machines on the brain by boiler I mean the hot tank and by HX i mean the long spiral pipe inside it that heats the water. So you have to be in the airing cupboard near the 3 way valve and checked the pipe going into the hot tank is hot enough, or hot as it should be, which would be almost 50C if your boiler is set to output hot water at 55.
I see you have more than 1 motorised valve and something that looks suspiciously like a 3rd on the right of the tank on the floor. I don’t really understand why you would have so many on a simple vented system with a simple system boiler? But hey, what do I know, I’m not a plumber.
Usually though you have a heat source, a pump (which will all be in your boiler), pumping up to a single 3 way valve for HW and Rads. The HW will often run the towel rails and heat the HW tank) the CH position may, or may not heat the towel rails as well….and shared, the third position will send hot water to both. I can only think for some reason they have your hot water on a separate 3 way valve, to try and do something clever with the towel radiators.
If you set the boiler for hot water only, track which valve moves and then source the pipe from there to the HW tank that the boiler is feeding. The upper pipe should be the hot into the tank and the lower one the return to the boiler. You won’t have a feed and expansion tank of course, that will all be inside the boiler and some of them can even have the 3 way valve fitted in the boiler.
