Plumbing question about bleeding radiators!

[ShaniceWearsMostlyGlitter]

We have had a 'sealed' system installed (megaflow). We had a room re-decorated and when the decorators finished they didn't tighten the nuts on the radiator back up. As a consequence, when I turned the thermostat on, on the radiator the other day (it was on 0) water came pouring out. DH has tightened the nuts up, no more leaking, but also no heat! Do we need to now bleed the radiator? We weren't sure about buggering about with the pressure in a sealed system.
Does anyone know?! Thanks.

The leak will have almost certainly let air into the system. It's probably worth bleeding all the radiators. Most likely either the impacted radiator or the 'highest' radiator in the system will have air in it.
You should also have a pressure gauge somewhere near your boiler. Check to make sure that it's not reading 0. If it is, you'll need to top up the system.
Depending on how the system has been installed, topping up the pressure is normally a simple DIY job. There should be 2 valves to turn to top the system up. There should also be a marker on the pressure gauge showing the expected pressure when the system is cold. If you're not confident about topping up the pressure yourself, a plumber really shouldn't charge any more than the minimum call out charge to fix - it should be a 10 min job!

If you bleed the radiators yourself, top up the system a bit first and after each radiator. If the system pressure gets too low the boiler might have a safety cut out. Bitter experience talking

Ok thanks! I'll go and check the pressure and see what it is and we'll then bleed the radiator and see what happens. Pah, a lot of hassle caused by bloomin' decorators.

Funnily this happened to me yesterday. A radiator was falling off the wall as a bracket was broken so after i decorated I patched up the wall, put on new brackets and put the radiator back on. Luckily there were some plumbers in next door who had a radiator key, ( recently moved and couldn't find mine) I couldn't run the keys at all so one of them kindly came in and showed me what to do. We started at the point furthest from the boiler and bled each radiator. Plumber also showed me how to top up the pressure before and after, it's really very simple but I had no idea before. Hope you've got yours sorted now

Thanks. Heating seems to be working (apart from the one radiator) so I'm going to leave it until this evening so I don't freeze during the day if I bugger it up! Also dh can help me then - I don't know how to bleed a radiator so I'm going to get him to show me how.

Disclaimer: I can change a tyre.