Help with draining down system

[Serval]

Im in need of a bit of advice with trying to drain my system down.

Its a fully pumped system.
The system does not have any drain off taps so i've used a rad valve with a compression nut and a short length of pipe to make my drain off

heres what i've done so far:
-switched off CH
-set both motorised valves to latched open
-drained a s ingle downstairs rad ( the one where ill be draining the rest of the system from)
-drained all the upstairs rads (all upstairs air vents are open)

the problem im having is that after the flow of water from the upstairs rads stopped, I moved down stairs to open the air vents on the down stairs rads however, instead of sucking air, in the down stairs rads are spitting out water and not draining.
(The TRV's and the lockshields on the downstairs rads are fully open)

Anyone got any advice on what i need to do.

 

[king of pipes]

Tie the ballvalve up in the small heating feed and expasion tank or if possible isolate via a valve on the supply to the tank . cheers kop

 

[townfanjon]

Your downstairs rads maybe on drops is your ground floor solid or suspended timber ?

 

[Serval]

Tie the ballvalve up in the small heating feed and expasion tank or if possible isolate via a valve on the supply to the tank . cheers kop

yep done that already

 

[Serval]

Your downstairs rads maybe on drops is your ground floor solid or suspended timber ?

Yes i believe they are although i can't find the drops as they are hidden behind walls.

Solid concrete floor downstairs, pipes all buried under the concrete.

What next?

 

[townfanjon]

Yes i believe they are although i can't find the drops as they are hidden behind walls.

Solid concrete floor downstairs, pipes all buried under the concrete.

What next?

Thought so , you will have to drain each rad individually.

 

[townfanjon]

Edit .... If they are on drops you shouldnt have any pipes in the floor .

 

[Serval]

Right, I will set about draining each rad then.
Now that you mention it i think this maybe what i ended up doing last time id did it ( it was a while ago so cant fully remember!)

Edit .. If they are on drops you shouldnt have any pipes in the floor .

Hmm maybe they're not then.....everything downstairs is on 10mm microbore set in concrete apart from 2 rads in the conservatory which are on 15mm

Ive struggled to confirm exactly how and where downstairs rads are fed from with all the decor in place

 

[townfanjon]

Drops are a pain but they are better that pipes in concrete or screed

 

[Serval]

Edit .. If they are on drops you shouldnt have any pipes in the floor .

So, the majority of my rads (5 out of 7) are fed from pipe work that is buried in concrete ( not sure about the other two as i don't know what subfloor is conservatory flooring)

Based on your quote above, how would (should) pipes buried in the floor be fed? assuming they are not on drops