How to drain a system with no radiators attached?

[AlastairK]

Looking for a guide on how I can go about draining the central heating system with no radiators attached. They had previously sprung pin hole leaks last year, and have been removed.

Will I need some HEP20 to join up each radiator?

 

[Agile]

I dont see exact what complications you have in mind!

Whats the problem with draining each valve into a bucket?

Tony

 

[landyandy]

What type of system have you got. Combi etc.

 

[AlastairK]

An old unit - Glow-worm 25-30B. It has an expansion tank which fills up the system. Hot water runs off a separate unit.

 

[calorific]

Try one of these for size

 

[AlastairK]

Cheers.

I had opened the drain valve at the bottom of the system and all had run clear, but then when I removed the return side valves for replacement, old dirty water went everywhere!! Grrrrr
I had previously filled and emptied the system 20 times, till the drain water ran clear. But for whatever reason the return side did not empty, even though the drain valve at the lowest point had been open on many many occasions.

 

[calorific]

There's a certain "law" (relating to turf ) that kicks into play with these things. Draining the main pipes and running it until clear unfortunately still leave sections of the legs untouched.

What are you asking about the Hep for? Bit confused about that

 

[AlastairK]

I just don't understand why the whole system did not drain when I opened the lowest drain valve.

I have been filling it up, and running the heating to pump round the water, draining it, until it has been emptying out clear.

But now when I removed one of the lock valves on the return side, I find a ton of dirty water still in the pipe work! Arrrggggg

If I purchased some HEP20 and joined up the valves on each radiator together, I could then open up all the valves, fill up the system, then hopefully when I drain it, the full thing would empty?? - Would that be the best way?

I just do not want to put on 5 new radiators and fill them up with old rusty water. It would just be a total waste.

 

[calorific]

You may have been running water round the main circuits, but unless you had flow through the legs then they wouldn't have cleared.

An easy alternative would be to connect the hose to the mains and through each valve and let it drain out through the drain-off.

Don't know if you have a magnaclean or similar on the return pipe to the boiler, but it'll help to collect rust while the system operates.

 

[AlastairK]

Thanks Calorific.

I don't have a hose water supply here, but could rig something up to the kitchen tap and use it to push through the legs and out the drain valve at the bottom. No magnaclean sadly, but will look at fitting one on.
Got some Sentinell X100 once the new radiators are on, and will add it into one of the valves, then fill up the system and bleed out the air.