why have 2 drain cocks for CH

[RobTi]

Hi riend asked me to replace faulty rad valve and when i went to drain down the heating found 2 drain cocks right next to each other, this is on a build of around 10 years old is this a new thing

 

[ianmcd]

if it is a system boiler then one drain down for CH and the other for the HW cylinder, if its a combi then one for flow pipework and other for return not as common but good practice

 

[RobTi]

if it is a system boiler then one drain down for CH and the other for the HW cylinder, if its a combi then one for flow pipework and other for return not as common but good practice

System boiler with megaflow, but fernox in both pipes, all houses had them (had a quick check) up in wishaw

 

[SimonH2]

If it's a two pipe system then there should ideally be 2 drains - one at the lowest point of each pipe. Depending on system layout there may be multiple low points which should all ideally have drain points.

Of course, some installers pay lip service and may fit a notional drain point which doesn't really drain the system and leaves a lot of pipework still filled. And if your one of the numpties employed by BG to install the system in my mates bungalow (before he had it), it won't work because they'll have melted the washer while soldering it in

 

[Dan Robinson]

DOCs are flirking useless any way.

Never bother with them unless I plan to replace them.

 

[Happyplumber]

Normally a good idea to have drain off 's on all drops or design it so the flow and return are put outside at their lowest point

Saves the hassle of dragging a hosepipe halfway across the house

 

[SimonH2]

There are a couple of points under our floors where there's a couple of old taps leading to an inconspicuous 1/2" tapped bush (with plastic plug) in the wall outside.