drained central heating, but water still in pipes

[cheapskate]

Hi,

aswell as the bathroom (another thread) I'm replacing a couple of radiators in my hallway. I've drained the central heating as well as can be, however there is still water in the 8mm pipes, syphonage keeps the water just at the end of the pipe. I am unable to fit a solder ring expander to 15mm as the water is boiling and running inside the fitting, the flux boils off but solder is not melting. I've practiced with soldre ring and some old 8mm pipe, so I'm sure the problem is not my technique - it's the water..

Any ideas on how to have more water removed from the pipework?

sorry I should have been clearer about the draining. the 8mm pipes are buried in concrete, and so are below the lowest drain point, which would be why they are still full of water.

without gravity helping out I'm unsure how someone would go about draining them.

my flat is one quarter or a four in a block, I have no way to access the feed and expenasion tank so all I could do is lock the gate valve which tops up the central heating. I think this means that air can't get in at the top of the system which will allow the water to escape at the drain point, though that still doesn't explain how to deal with pipes which are below the lowest drain point.

 

[stevetheplumber]

going on what youve said surely you can disconect the gate valve on the side thats empty this alone may let in air to alow the pipe work to empty if not it will have to be blown or sucked out ive connected a compresor before now to clear pipework or maybe a wet vac ?

 

[cheapskate]

I've been using a straw and my finger and have been able to get rid of some of the water, but I think I'll do what you say and disconnect the pipe south of the gate valve too.

thanks a million

 

[Plucky]

This is where a water hoover is your best friend

 

[newbie1]

just got a lovely draper 30l was doing a boiler other day drained but loads of water came out..would never have managed to solder otherwise

 

[cheapskate]

wow straw and finger did it, I was able to remove enough water so there was no boiling of water during the soldering stage. of course the real test will be when I turn the pump back on.. ;-/

 

[Torsionbar]

I have seen where a small hole is made just below level needed so water runs out - solder fitting on and screw in small brass screw and solder over - also seen steel wood screw and matchstiks etc - not longlasting

 

[migoplumber]

if your not used to soldering, then its best to wait for a dry pipe! as said above, you could have a vacume in your installation allowing drips through, you could break the nut below your gate valve to solve this. as for pipework below your drain off, you need to get that water out any way you can, wet vac, straw, tissues, insert something into pipe (that you wont lose) that displaces the extra water.

you could always use compression for easiness?!

shaun

 

[Winston]

A bit of earth sleeving or I prefer a clear flexible hose so you can see before you swallow it 🙁 And if your new to soldering use MAPP gas the heat is greater and more forgiving, but be aware alot hotter scorch marks!

 

[Plouasne]

A bit of earth sleeving or I prefer a clear flexible hose so you can see before you swallow it 🙁 And if your new to soldering use MAPP gas the heat is greater and more forgiving, but be aware alot hotter scorch marks!

I would also say if using something like MAPP do not "over cook" the solder, and burn the tin out of the solder

 

[Hugh]

wet and dry vac (great job)

 

[cheapskate]

thanks for the last two replies, I've only just been informed of them. I will look up MAPP gas but as it is I seem to be getting along nice with the propane torch I have.

Something terrible happened last night though, just below the flooring level the 8mm had a twist in it (which I knew nothing about) well my fiddling has twisted it further, cracked it and last night I noticed water seeping along a crack in the flooring.. :-(

I turned off the pump, drained the central heating and dug around the cracked 8mm pipe. I'm now going to lift the majority of my kitchen flooring to try and save it, and compression joint a new length of 8mm below the crack, sounds reasonable?

 

[danielp]

thanks for the last two replies, I've only just been informed of them. I will look up MAPP gas but as it is I seem to be getting along nice with the propane torch I have.

Something terrible happened last night though, just below the flooring level the 8mm had a twist in it (which I knew nothing about) well my fiddling has twisted it further, cracked it and last night I noticed water seeping along a crack in the flooring.. :-(

I turned off the pump, drained the central heating and dug around the cracked 8mm pipe. I'm now going to lift the majority of my kitchen flooring to try and save it, and compression joint a new length of 8mm below the crack, sounds reasonable?

normally this happens to the best of just as your leaving on a friday night 😎 , that is good or you can replace with 15 mm get an 8-15 mm compression connector and change the rad valve then you can tee in a dran valve ?

 

[justlead1]

Hi. Push an elbow on the pipe with a piece of pipe in the other end and blow, take elbow of mup up and keep repeating till no water. Good Luck

 

[cheapskate]

normally this happens to the best of just as your leaving on a friday night 😎 , that is good or you can replace with 15 mm get an 8-15 mm compression connector and change the rad valve then you can tee in a dran valve ?

the rad is 15mm already with a drain valve. I just need to replace 8cm of 8mm pipe and refit a new reducer.

 

[smoggs03]

normally this happens to the best of just as your leaving on a friday night 😎 , that is good or you can replace with 15 mm get an 8-15 mm compression connector and change the rad valve then you can tee in a dran valve ?

hahaha yeah 🙂