Drain cock

[notb665]

My BOSCH combi boiler is upstairs. It services 3 radiators upstairs and 2 zones of underfloor heating downstairs. I asked the plumbers who installed it to send two pipes down into the (downstairs) bathroom so at some point I can attach a heated towel rail. That time has now come. The two pipes are just capped off at the moment.

One of the underfloor heating zone's supply/return pipes has a draincock on it. This I have used before to empty the system etc etc.

My question is: Do I need a draincock on the heated towel rail?

Thank you please.

 

[ChrisR]

Well it'll work without one, but it saves trouble if you ever need to drain the pipes it's connected to! Conventionally, yes.

 

[notb665]

Thank you very very much.

 

[notb665]

Another thought, which pipe do I connect it to? How can I tell which is the supply and which is the return?

 

[chrishutt]

Doesn't matter. Both pipes connect to bottom of rad / towel rail. Flow water will rise to top of rad because it is hotter (and therefore less dense / lighter). As water looses heat it will descend towards bottom of rad where it will be drawn away by return pipe.

 

[doitall]

Your not thinking of connecting it to the underfloor circuit are you

 

[notb665]

Thank you all.

No, I wasn't going to connect it to the underfloor heating pipes. May I ask why you asked this?

 

[blahblah]

If using a straight trv check for arrow direction and make sure it goes with the flow.