Rads Hot Upstairs. Cold Downstairs

[malooga]

Hi,Would Really apprciate some expert advice.
Firstly about 2 months ago i changed our bathroom and took off the rad a replaced it with a towel rail.
A few weeks later turned on the heating, Mrs complained that the rads downstairs werent very warm didnt take much notice. Then last week i turned the heating on again now theres no heat at all in the rads downstairs. ive just put in a new pump, Grundfos 15/60 drained the system still no heat downstairs. Maybe i didnt drain right. when the pump is running there is a sound of air rushing through the pump about every 30 secs.

 

[seco services]

have you bleed the pump ?
if all your rads are now cold water is not circulating

 

[malooga]

Yep ive bleed the pump and the rads upstairs are red hot

 

[seco services]

i would say you have a airlock in the downpipes to the rads.
shut upstairs rads then all the flow will go to downstairs pushing out airlock.

 

[malooga]

which rad do io pen the bleed srew on

 

[seco services]

none
so shut the upstairs rads stick pump on speed 3 and wait.

can you see the two pipes that may come down the wall to feed the downstairs rads, if so keep feeling them and they should get hot.

then when downstairs hot the upstairs can be reset and bled

 

[malooga]

sorry about the spelling. i'm really not that bad just rushing it. HONEST Ha Ha.

 

[malooga]

Cheers. just going to give that a go now. i'll let you know how it goes.

 

[seco services]

please do

 

[malooga]

The rads downstairs are warm at the top now have been for a while.
will they heat up all the way or do i need to bleed upstairs.

 

[seco services]

no let it run for a while.

have you only got downstairs rads open ?
are they only hot at the top of the rads ?

 

[malooga]

yep just downstairs open, they are about half heated now

 

[seco services]

abit slow.
whats the condition of the system water when you drained it ?
is it a large system etc ?
is the pump on 3

 

[malooga]

The water was pretty clean. I've got 4 rads upstairs and 4 down. The pump is on number 3

 

[malooga]

Actually it seemed a long time to drain. (about 3/4 of an hour.