Sheared Drain Cock

I've been putting off draining down the central heating system until now. An odd, to my mind setup, but here goes: Oil fired boiler. Indirect cylinder. 1 3-port valve that does HW/CH or both. Odd that in after the CH take off from the 3-port I have another TWO, 2-port valves. One does the upstairs rads. The other the downstairs one. Wall stat upstairs & a second one downstairs. The upstairs rads are plumbed with each rad connected to the flow and return. BUT the downstairs CH system is an old fashioned SINGLE PIPE, 3/4" nominal bore system.

I had planned today to drain down and re-route a couple of the SINGLE PIPE system pipes as a stop gap before it all gets replaced. Went to undo the drain cock (great place BTW, behind the TV in the lounge). Had my hose all set out of the patio doors and it wouldn't budge. Tried penetrating oil after wire brushing the gloss off, Heating with a MAPP torch. Ended up shearing it off flush in the end as per photo. Then tried cutting a slot in the sheared off face to fit a plate to turn it with. Nothing works the thing is SOLID. To be honest it's not even at the lowest point on the run but would be ok for what I want to do.

Any suggestions? Thinking it'll be try and jury rig some say lengths of kitchen waste pipes out of the patio doors and just accept there's going to be a few wet carpets etc. Cheers.

How about one of those self cutting outsise tap kits??

Not a plumber and don't know a lot about it but how about a freezing kit and just putting a new drain off point in at lowest point? As I say don't know a lot about plumbing.

I feel your pain!

Is the copper pipe with the straiht connector on it metric [if not then the following prob wont work] however I have tried this and it works and there is not that much water

get 2 pushfit isolator valves

turn off pump

turn off boiler

seal overflow of ch header tank , i used a 15mm push fit stop end FFS DO NOT FORGET TO REMOVE THIS WHEN YOU HAVE FINISHED I T

Clean the pipe where you are going to cut it

F quickly cut the pipe an remove a section greater than the combined length of the 2 push fit fittings

F quickly shove the pushfit fittings onto the cut ends of the pipe

you have now created an isolated break in the pipe

since you have cut out more pipe than you need you can now fit a new drain cock, open the isolators, remove your temp 'bung', have a coffee, Calm Down and Carry On

I have done it a few times, you just need the right bits AND confidence

If it all goes wrong don't blame me as this info is worth what you have paid for it...somebody will come along shortly with a better idea no doubt...... :coat

How about one of those self cutting outsise tap kits??

Click to expand...

Did cross my mind but had a cursory look and could only fine them for 15mm.........

---------- Post Auto-Merged at 22:53 ---------- Previous post was made at 22:38 ----------

I feel your pain!Is the copper pipe with the straiht connector on it metric [if not then the following prob wont work] however I have tried this and it works and there is not that much water

get 2 pushfit isolator valves

turn off pump

turn off boiler

seal overflow of ch header tank , i used a 15mm push fit stop end FFS DO NOT FORGET TO REMOVE THIS WHEN YOU HAVE FINISHED I T

Clean the pipe where you are going to cut it

F quickly cut the pipe an remove a section greater than the combined length of the 2 push fit fittings

F quickly shove the pushfit fittings onto the cut ends of the pipe

you have now created an isolated break in the pipe

since you have cut out more pipe than you need you can now fit a new drain cock, open the isolators, remove your temp 'bung', have a coffee, Calm Down and Carry On

I have done it a few times, you just need the right bits AND confidence

If it all goes wrong don't blame me as this info is worth what you have paid for it...somebody will come along shortly with a better idea no doubt...... :coat

Click to expand...

Cheers for that. Yep, the pipe to the right is 22mm metric - just squeezed behind the TV with a vernier after putting it all back and settling down to watch Avatar! Why plug the overflow to the header tank can I ask - presumably to not introduce air and "hold" the water in the pipes?

http://www.supremeplumb.com/cgi-bin/DMdatabase.cgi?action=/home/suprem13/public_html/cgi-bin/home/Shop/Plumbing_Fittings/Plumbing_Valves.txt&item=00120

22mm self cutting valve.

Supreme Plumbing & Electrical Supplies >> 22mm X 3/4" Self Cutting Washing Machine Taps - WMV020-SC22mm self cutting valve.

Click to expand...

That's cheap!

I lurk on the plumbing forum and I have shamelessly stolen this from there:

Trying to drain a heating system but some idiot hasn't installed a drain off ? . Select a rad ( downstairs of course ) isolate both ends , disconnect the lockshield or trv from the rad tail . Bung the rad tail with tissue. Turn the valve 90 degrees so it's facing you . Push a bit of 15mm pipe with nut and olive and tighten onto valve . Connect your hose , open valve and away you go

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Did cross my mind but had a cursory look and could only fine them for 15mm.........---------- Post Auto-Merged at 22:53 ---------- Previous post was made at 22:38 ----------

Cheers for that. Yep, the pipe to the right is 22mm metric - just squeezed behind the TV with a vernier after putting it all back and settling down to watch Avatar! Why plug the overflow to the header tank can I ask - presumably to not introduce air and "hold" the water in the pipes?

Click to expand...

yeo....theory is...if make up air cannot 'get in' then water cannot 'get out'. Just made a sort of temporary vacuum really

That's cheap!

Click to expand...

Thats what I thought too. For that price it's worth chucking one in the bottom of my plumbing box. The 15mm self cutter has got me out of the doo doo a couple of times.

Supreme Plumbing & Electrical Supplies >> 22mm X 3/4" Self Cutting Washing Machine Taps - WMV020-SC22mm self cutting valve.

Click to expand...

Cheers for that. Only thing that puts me off is you have to put your credit card details in FIRST and then they calculate the postage.....

Just checked their term and it's.

yeo....theory is...if make up air cannot 'get in' then water cannot 'get out'. Just made a sort of temporary vacuum really

Click to expand...

Ta for that. DIY store in the morning for some push fits. Just a bigger version of pinching the end of the straw in a glass! Going to be great fun I can just about get my head and shoulders in - can't even get access to look into the tanks! It's a slow, slow process ripping out the old, making temporary fixes etc and renewing with a view to proper access and maintenance. Everything was done shortest distance between two points etc. Lucky the electrics aren't in the same state..........hang on, THEY ARE!



---------- Post Auto-Merged at 23:52 ---------- Previous post was made at 23:37 ----------

Just checked their term and it's.

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used to do a fair bit of plumbing but had to give it up as I found it too draining..... :coat

If you can't shift a drain cock or there is no drain cock (as is not uncommon!! headbang ) ..

I would have just drained one radiator then took it off the wall..

Then stuck a standard hose - threaded tap connector on the end of the pipe rad valve..

Stick hose in to drain..

open rad valve..

water drains off..

when empty.. cut pipe around offending stop cock..

solder new one it!

Refill

Jobs a goodun!

:coffee

These self cutting washing machine type "taps" - what happens when it cuts into the pipe? Does it puncture the pipe (like a Party 7 can )or do they punch a lump out that then gets pushed round the system? A bit worried about the CH pump!

not sure mate but i would do what specs said and whip a rad off.

Little update: So I ordered a couple of those 22mm self cutting washing machine taps. Used a couple on 15mm years ago but never really examined the mechanics of it. So I put one on an off cut and then promptly took it off again. Seems both the clamping action and the cutting action deform the pipe a bit into an oval (thicker wall pipe might help). The "worrying" bit for my use though is that they "punch" a 1/4" diameter disc out of the pipe and it's debatable as to whether that would stay in situ during the installation process or detach and go whizzing round the system and into the CH pump! Though saying that as you hand screw the cutter in you feel it "give" and it sort of hinges the copper disc inward without breaking it off. Go too far and it does get removed fully. I reckon I'll take the chance and once it's all drained down replace that section of pipe and HOPE the disc is still in place!

OK.

If you`ve isolated the supplies, turned everything off etc - there is NO FLOW to move the copper offcut anywhere.

However - I wouldn`t put a self-cutter in. I`d drain a rad - bonus being:

1. No faffing with the header tank. If you`ve shut the two rad valves, undo one, plug it with a finger (if its a BIG rad, you might need a fitting on t`end with a stop) then undo t`other end and remove said rad. This also allows missus in for decorating purposes. which can be worth major brownie points!!!!!!)

2. You can attach a standard 3/4 x 15 (flexi / cap & liner), shove your hose in, and open the valve - system drains down. Now piece of poo to fit drain off.........

tip a: Don`t use the combined rad valve / drain offs - they`re total carp

tip b: drain offs at the lowest point tend to collect the crud in the system, which is what seizes them up - cos they don`t get moved for aeons.

tip c: if you DO fit a drain off somewhere - and its a sweated fitting - remember to take the insert out first, otherwise the rubber`ll melt, then it`ll leak.

KME

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I do hope that is NOT the best leather armchair that you have put the nasty bit of copper pipe onto!!!!!!

:shakehead