Plumbing Question!!!!!!!!!?

I have replaced a radiator today. I drained the system down (a sealed system). Took off the old radiator and replaced with a new one. When i filled the system back up to 1 bar, i turned off the filling loop but the pressure still rose to 2 - 2.5 bar and the boiler will not ignite. I know that the pressure should be 1 bar when cold but i dont know why it has risen? I have bled all of the radiators but to no avail. The boiler will not ignite at all on the central heating but will ignite on hot water demand. Can anyone help on this????

Public Comments

1. Does it have an auto fill valve? If so the fill valve float is stuck usually due to water minerals, causing the high water switch to cut out keeping the burners off. If manual fill then the water valves is not shutting completely off letting water to continually fill and activating the high water cut- switchout.
2. i think you need to reset the boiler system in order to adapt to the new radiator try to reset the whole system
3. I know this might seem really basic - but you haven't left any of the valves shut on the boiler have you? Other than that - it sounds like the flow sensor isn't sensing flow on the heating system, (the domestic sensor is obviously working because you get the unit to 'fire' on hot water demand). Who's boiler by the way?
4. The Question is after you install the radiator did you get out air from system or not . 1- When you add or replace new device to the close system such as radiator system you must open return pipe to the system and then for short time let the water pass all the system and come out from the return pipe . 2- when incoming and out going pressure be the same then closed the return pipe valve and connected to the system then check the gage . 3- If there be air in system the boiler will not ignite.