FAO YBIG Tradesmen

Turn heating off, then turn each radiator off at the nozzle.

Now turn heating back on again and turn nozzle in hall 1/4 of the way until you start to hear a flow and feel it heating up.

Now do the same with each rad one at a time. Leave them all at 1/4 of the way turned. Makes no difference to the temperature they get up to, it just takes slightly longer to heat.

It's definitely less if the whole apartment is one colour. If some of the rooms are different, it'll cost a bit more, because then not only do you need extra paint, but there's extra time cleaning brushes and rollers and the like. You're obviously far better off supplying the paint and all yourself.

It also depends whether you just want the walls done or if you need everything else done too (doors, skirting, sills, rads, that sort of thing) as the extras are very fiddly, use different paint and take longer. Chances are the doors and rads don't need done but you can count an extra few hundred if you want all that done too.

Try it again, but this time, don't turn back on upstairs. Once they are all hot downstairs, turn them off again and repeat once or twice more downstairs. It is usually just a flow thing.

Once downstairs is boxed off, slowly turn on upstairs one at a time. It can take a bit of patience.

Probably the thermostat is jammed. Take off the thermostat and there is a pin on top of the valve, put a drop of oil around the pin then press it up and down a couple of times and put the thermostat back on, twist it full open and back to cold a few times see if that works