Bathroom towel rad

[Thurston]

I'm changing my old 1960s bathroom radiator for one one those new chrome towel rail jobs, and would welcome some advice about draining the system.

I have worked out that my bathroom rad is fed from the pipes which heat the hot water cylinder, so the rad works independently of the central heating system. I'm taking the opportunity to get rid of surface mounted pipes to the old rad with new ones embedded in the wall. To do this I will need to replace some sections of the pipework in the loft because the old T joints carrying the feed down to the bathroom are in the wrong position for the new rad.

My question - at last - is this: what do I need to do to drain the system so I can replace the sections of the feed and return pipes from boiler to hot water cylinder in the loft? There is a drain cock on the coldwater feed to the cylinder, but how do I shut off the supply so that it actually drains the system and does not carry on filling up? Also is there anything I need to do to avoid an air lock when I refill the pipework.

Thanks in advance and any advice welcome.

 

[Dannypipe]

You don't need to drain the water in the cylinder. It's the water in the coil which is in the cylinder that heats your towel rail.

Therefore you will probably need to drain your central heating system.

From the sounds of your house, you probably have an open vented heating system (two tanks in the loft, one big and one little).

Just shut off your boiler, tie up the ballarm on the smaller tank, or better still switch the feed to it off via a stopcock. Open a drain point on your central heating system and drain it. Be warned though, you shouldn't attempt this job unless you are practicle and have some experience as you could make a mess, or just cock it up completely. You need to ensure any motorised valves to the coil are open.

I could do this work in about 2 hours. Sometimes it is just easier to pay for a professional plumber, as you could make mistakes here.

On my system I installed valves feeding the radiator from the coil, so if I have to work on the towel rail, I don't have to drain the system.

Finally make sure you dose the system with a corrosion inhibitor after you finish.

Best of luck.

Danny

 

[justlead1]

Hi. It is important to identify the type of system you have before giving info on draining down. Are there a small and larger cisterns in the roof space?
Is there a drain off cock on the return pipework on boiler?

 

[Thurston]

Hi. As in my reply above, I have an open vented system with the two tanks in the loft. The central heating is on a single 22mm pipe system - installed in the 1960s, but it seems to work efficiently. The pipes I need to replace are sections of the 22mm feed and return to the heating coil in the hot water cylinder. Someone in the past has helpfully labelled the various pipes in the loft.

There is a drain cock on the central heating circuit just in front of the boiler (ie the return flow). Unfortunately it appears to be jammed.