HI,
I have a problem with just one radiator staying cold. The others in the flat are very hot and work well. It is a German central heating system in a block of flats, and there are no traditional style bleed valves like im used to in the UK. I have no access to any pumps or tanks!
On the top right of the rad is a thermostatic valve on a pipe and on the bottom right is another pipe going into the rad with a valve with a short outlet pipe and in that is an allen key that opens the (i think a three way) valve through 90 degrees. It looks like the little outlet pipe is designed to have a 25mm hose fitted on it maybe to avoid spilling water when it is open. Anyway the thing is that if you open the valve black water comes out of the outlet under pressure but this soon becomes a trickle and stops. The allen key can turn through 45 degrees (which stops the water flowing out the pipe) or 90 degrees (which seems to cause the radiator to make a noise like its filling). If the allen key is returned down 90 degrees it will allow the black radiator water to flow again under pressure until once again it trickles to a stop again.
Not a clue what to do with it! Help!!
Martin...
I have a problem with just one radiator staying cold. The others in the flat are very hot and work well. It is a German central heating system in a block of flats, and there are no traditional style bleed valves like im used to in the UK. I have no access to any pumps or tanks!
On the top right of the rad is a thermostatic valve on a pipe and on the bottom right is another pipe going into the rad with a valve with a short outlet pipe and in that is an allen key that opens the (i think a three way) valve through 90 degrees. It looks like the little outlet pipe is designed to have a 25mm hose fitted on it maybe to avoid spilling water when it is open. Anyway the thing is that if you open the valve black water comes out of the outlet under pressure but this soon becomes a trickle and stops. The allen key can turn through 45 degrees (which stops the water flowing out the pipe) or 90 degrees (which seems to cause the radiator to make a noise like its filling). If the allen key is returned down 90 degrees it will allow the black radiator water to flow again under pressure until once again it trickles to a stop again.
Not a clue what to do with it! Help!!
Martin...
Maybe the thermovelva ist not working ans stuck closed 
