No drain valves on radiators?!?

[craynerd]

I went this afternoon to do a job at my grandads house which required me to drain the CH system. He has a vented system with header tank in the loft.

I looked and looked and none of the radiators had a drain valve!! I was totally confused and openly admitted this too him.

He told me that when people have "done jobs before" they have drained the system from a drain valve which is located right above the boiler in the garage! I'm not saying he is wrong, but since this is at least 6 to 7 foot off he floor, surely if this is a drain, it wouldn't drain the downstairs radiators I want to work on.

He also showed me 4 copper pipes all with drain valves on them in the garage. Two of them were 15mm pipes and one of them was directly connected to the hot water(tap water), one to the cold water (tap water). And the other two were 22mm copper pipes and I couldn't tell what these were but again had drain valves on them at ground level.


I wanted to wait to ask on here before I did anything! Any idea what the drain valve above the boiler is for and what the two 22mm copper pipes could be for??

The system had been drained so I must be missing something!!

 

[ianmcd]

The two 22mm pipes are most probably the heating circuit,open them and see if the water is clean or dirty if it is dirty them most probably from the heating/indirect HW side

 

[craynerd]

Thanks for that! probably a daft question but why would there be two pipes to drain that system?

 

[CBF]

it's not two pipes to drain the system it's most prob the flow & return for the heating, the drain off on the boiler will drain the upstairs & also allow the boiler to be changed with min water being left in it

& you are going to do work on his heating system

 

[Armo74]

You sure it's an open vented system?

From your discription it sounds more like a combi to me.

 

[HERTS P&D]

Also always fit new washers to drain cocks when drained down.

Andy

 

[craynerd]

Cheers guys... Yes, I've got a combi and it is 100% not a combi!! The header tank is in the loft, the hot water tank is in the airing cupboard with the water pump....

Thank you for the info...

Chris

 

[oilboffin]

Go to bes they have drain offs in the book that clamp to 15mm pipe and cut their own hole if you like you can leave them on if they are not in the way they really get you out of trouble

 

[craynerd]

Hi chaps, just got back!

I just wanted to report that the two 22mm pipes in the garage didn't drain - either the valves were faulty or he pipes empty since I unscrewed both valves and there was no flow of any water

Anyway, I got the rad off and drained system by carefully emptying from the radiator valve. Re routed one of the pipes, added inhibitor, filled and bled and all seems to be working ok.

So although job is done, I'm still confused as to where the drain point is when I'm certain here is one somewhere!

Chris

 

[john90]

not all systems have drain off valves. Good practice to have them though. Maybe you should have stuck one in for next time

 

[Dan Robinson]

I don't use them even when they are there.

Generally useless things.

 

[craynerd]

I don't use them even when they are there.

Generally useless things.

Why is that?? How else do you drain the rads when needed??

 

[Dan Robinson]

Jedi mind tricks mate.

DOC's cause more trouble than they are worth. At best they don't work. At worst the damn spindle snaps just as it starts to pour and there is half an inch between the spout and the floor.