Does anyone know what these pipes are for?

[Jaygray]

Hello,

I have two 22mm pipes running to the corner of my room and under my fireplace.

Both get hot when heating is turned on and I have a two pipe system, so I think they are feed and return.

Mu question is, why do they have drain down valves on them?

Why do they run under my fireplace.

There's not a raiditor nearby. Although its an old house and might have of had one years back. Even then, it's a 22mm pipe.

 

[RandomGrinch]

At one point you may have had a back boiler within the fireplace.
The feed and return pipes have simply been left in place.
I had similar behind my fireplace, before I took out the deadlegs.

 

[Jaygray]

Ahhhh you might be right. As there was a gas fireplacer, which has been capped off.
How would I know if I can cap.off the dead legs?

 

[fixitflav]

At one point you may have had a back boiler within the fireplace.
The feed and return pipes have simply been left in place.
I had similar behind my fireplace, before I took out the deadlegs.

Even though they both get hot?

 

[RandomGrinch]

Even though they both get hot?

If there are any pipes left at all, it's likely that both a flow and return pipe are still in place.
How they have been kept integrated into the existing radiator circuit is another question.
Mine were 5m long dead legs!
If the legs were shorter, having the legs looped, or if the pipes are still part of the circuit, could all keep the pipes warm; further investigation is needed by the OP, before anything is removed.

 

[Jaygray]

Thanks Randomgrinch. I'll take more photos over the weekend. I think a dead leg, originally installed to feed the frontroom.

 

[fixitflav]

I think a dead leg, originally installed to feed the frontroom.

In which case I'd be surprised if they got hot, unless the dead leg is quite short. Do they got hot at the same time as the rads (or sooner) when the boiler starts?

 

[JohnD]

Have you got a hot-water cylinder?

 

[Hugh Jaleak]

I'd hazard a guess they were part of an earlier 22mm pumped circuit feeding the Rads, from a Back Boiler. When that was removed, the Plumber simply tapped into the Radiator circuit elsewhere at a convenient point, and capped the original connections off, as per your photo.

That's a 1/2" iron plug, in the elbow, not designed/fitted to be a Drain Off.