Blocked Cold Feed questions.....

[footballfan]

blocked cold feed - after reading the FAQs and from what I know already - if when venting radiators (usually top floor/higher ones) water doesn't come out with any force - and can also be dark in colour and thickish. But does the F & E cistern height have anything to do with this .... and is hot water always affected?

The cure if there is circulation is X400 followed by x100 i presume, but if a cold feed is blocked so bad that no circulation is happening - then the pipe will need to be cut out, blockage removed, and pipe replaced (using compression fittings is best i believe)? the only thing is, how do you know if the pipe is 100% blocked? anyway of testing? (magnet on pipe)??

 

[seco services]

try draining the system if the f/e don't empty you know its blocked.

why do you say replacing the pipe with compression fittings is best ?
if it can be soldered back in solder it.

 

[footballfan]

i don't have a blocked feed at the moment (touch wood) i was just reading through and trying to learn and got a bit confused with all the solutions, etc.

Some of the posts on here said the height of the F & E may make a difference, ... but how come with a blocked cold feed you can get hot water and no heat in upstairs rads, even if the hot water cylinder is on the same floor?!

About the compression fittings, it is just what I read and learned, as soldering wet fittings is difficult! Although I have done this before.

 

[seco services]

by the time you have noticed your cold feed is blocked is when the rads upstairs are not getting hot due to the low level of water in the system.
and the rads being slighly higher than the connections to the cylinder.

you'll probably find your pump will seize before the lack of hot water in cylinder as most pumps are about cylinder height.

 

[footballfan]

ok thanks for helping me seco services. yes you are right about the height of the pump/hw cylinder. i suppose a magnet attaching to copper pipe is sign/way to check also.i suppose the pump will seize / burn out due to firing with lack of / no water in pipe/circuit?!