Removed Radiator, now no hot water?

Removed rad from system and now no hot water. I have a Biasi M96.24sm boiler. The rad removed was an old rad and the valves have been leaking slightly. There is no pressure. I have put the central heating to standby, but even if i switch it back on it doesn't work. The lights indicate that there is a faulty primary circuit (no water or absence of flow) ... is this because I removed the radiator. Sorry I am a complete novice. I needed to remove the rad so that it can be plastered behind.