rads getting warm when heating is off!!

[handy]

when my hot water comes on the rads up stairs start to get warm? could hot water be cripping past the 3 way valve in airing cupboard? or can it be something else?

 

[newbie1]

divertor/3 port stuck

 

[migoplumber]

generally the motorized valve as you suggested.

 

[Hugh]

Change the 3 port buddy

 

[HTB]

there's always the possibility that it's always done it and theres a problem with the split return??

 

[pauls]

came across that problem today hot water had been teed into the heating and when heating was off 2 of the rads got hot