central heating problem

[plumbstupid]

hi all
in the summer i moved a radiator from one side of a bedroom to the other side , after testing it and checjking for leakks everything was ok
we have now turned the central heating on again for the winter and half the rads are not getting hot,
our house is of 3 storeys, top floor 2 rads work ok, mid floor, bathroom ok, landing and lounge not working, basement, kitchen not working ,snug ok. it is as well to say that the rads in the back are working but the ones at the front are not
i have tried empying and refilling, venting, closing all the ones off that are working, with no success
thye system is a baxi gas backboiler , the pump is fitted on the top floor and working, there is a 3 port honeywell control valve next to the pump, which i dont know is working or not
any help gratefully recieved
thanks
plumbstupid

 

[Agile]

What have you done to balance the system?

What colour was the water when you drained it?

Tony

 

[plumbstupid]

hi
i have not tried balancing the system as im not sure how too, the water when i drained system to move rad was black, when i last drained system it wasnt as black
thanks
plumbstupid

 

[Agile]

First you need to clean the system and only then you need to balance it.

See FAQ on this site.

Tony

 

[JohnD]

(the first few on here)

//www.diynot.com/forums/viewforum.php?f=7

 

[plumbstupid]

First you need to clean the system and only then you need to balance it.

See FAQ on this site.

Tony

hii mate i have just finished draining and flushing with mains cold water the system, we still have the same prob as before, i have closed all the rads except one and still its not getting hot
there is a bleed valve fitted to a pipe directly above the 3 way valve , every time i bleed it loads of air comes out
when i drained and refilled the system i drained it again straight away and the water was nearly clear
thanks
plumbstupid

 

[JohnD]

sounds like you have rinsed it with plain water but have not used a cleaning chemical to loosen the sludge and sediment.

Is that right?

 

[Agile]

When I said "clean" the system I did not just mean draining and refilling!

To clean might require power flushing or treatment with an appropriate chemical for the dirt.

It needs considerable skill and experience to know which chemical to use.

Tony