Winter is coming

Any help is much appreciated. What I can't understand is why a few of the radiators aren't heating up. I know they are full because when I bleed them the water comes out. Half (or more than half) of the radiators are warm and the others are cold.

This is the result of the system being drained and then filled and then started again. Could it be that I need to open all the temp guages up in order not to block the cercuit?

Winter is coming.

I don't much about boiler systems, but it seems to me that your system is plugged up with rust or other debris. I would try to do as you say and open up every possible drain orifice and keep flushing water through the system until you unplug it. If you could isolate exactly where the system is plugged, you would have an even better chance of fixing the problem.

Are your radiators supplied by circulating hot water or steam? The solution depends on the system.

Are the ones that are cold at higher level than the ones that are warm?

How far are they above the boiler/furnace?

My experience with hot water heating units is that it is easy for them to get air in the pipe and the circulating pump doesn't have enough pressure to clear it out.

If hot water, is there an air removal system in the circulating loop?

It's hot water heated. Today I went around to all the radiators and bled them - some had air and some didn't but all were full of water that's certain. I have put the pressure at 1bar maybe 1.3.

The radiators fall into three categories. Most get hot, a couple only get warm and about 5 are cold - all have water and filling the system went easily. Perhaps it's important but I put the pressure up and then went around one radiator at a time, bleeding them until they were full.

Do I have to bleed the system again just so that I can fill it again?

The rads are one different floors, some are hot some aren't. They aren't the furthest away from the boiler and besides the bleed valves, there is no way (that I know) to get air out.

I did read in another thread that perhaps I should drain the whole system and fill it slowly.

Did I understand correctly that your advice is to put more pressure into the system and keep bleeding so as to force the circulation?