Plumbing advice please

youngatheart_2

My husband has just drained our central heating system to replace some ground floor radiators. The system has an indirect boiler in the kitchen and a tank on the 1st floor. When he turned the water back on to the tank no water was dumped to the radiators and they will not fill but the tank is filling because when you run the hot water tap you can hear it refilling. When the radiators are bled only a small amount of air escapes but no water can be heard replacing it. Can anyone suggest a solution as he has tried everything he can think of?

plumb1_2

If you have a indirect system you will have 2 tanks( unless you have a primatic cylinder) the larger(25gall) will feed your cylinder/hot water taps, and the smaller (5 gall) will feed your heating, check to see if the small one is filling up, as the ballvalve tends to stick.

youngatheart_2

Thanks Plumb 1, I must have a direct system as there is no small tank. In the past when I have drained it, it filled up again without a problem, but for some reason this time it wont. Any ideas?

plumb1_2

youngatheart wrote:

Thanks Plumb 1, I must have a direct system as there is no small tank. In the past when I have drained it, it filled up again without a problem, but for some reason this time it wont. Any ideas?

I dought it will be a direct sysytem as only used on old solid fuel backboilers.
If you have only 1 tank, you will have a primatic cylinder, there should be a small air vent on the side of the cylinder which you will need to veny.
Be carefull as i have know them to snap off.