Central heating disaster - help!

[Avocet]

Worcester Heatslave oil-fired combi boiler. There I was, sticking some tiles on the bathroom wall. So I thought I'd be smart and slacken the unions on the bathroom radiator, lift it off its wall brackets, and "hinge" it down flat while I tiled behind it...

...and now the unions won't seal again and it's leaking! Both inlet and outlet are 10mm copper pipes. There's a Danfoss thermostatic valve on one end and a lock shield valve on the other end. Not sure what the unions on the radiator itself are, but the nuts measure 24.5mm and 29.4mm across flats respectively (the larger one being at the lock shield end). The radiators are original and the house was built in 1995, if that gives any clues? As far as I can tell, the leaks are from where the 10mm pipes go into their unions, rather than the large nuts on the bottom of the radiator.

I've tried tightening them and I'm worried that something is going to break. I'm really heaving on the spanner but the leak persists! I don't think they're compression fittings with olives in them, I'm not sure how they seal, to be honest. Clearly, I'm going to have to undo them properly and have a look at why they're leaking, but my question is this:

Can I "half drain" the system so that the water is below the level of the upstairs radiators and towel rail and then use the central heating to at least warm the ground floor of the house and the hot water, or will "bad things happen" if I try to do that?

 

[CBW]

They’re usually compression nuts, photo?

What I would do is isolate the flow and return under the boiler, close both sides of radiator, disconnect the radiator, and then open both sides (one after the other) into a bucket, and then you should be able to work on the system and see what’s going on. Fix the issue, rehang the radiator and connect, open valves under boiler, fill and test.

 

[Burnerman]

I’d reckon they are compression nuts, with olives, that didn’t take too kindly being lifted upwards, and overtightening will have crushed the olive.
Personally I’d disconnect and see what’s what, maybe you’ll get away with lashings of ptfe tape, at least temporarily.
John

 

[terryplumb]

Quite possibly reducer sets , 10 mm pipes going into 15 mm valve tails . Over tightening them will worsen the leak. You will need to drain down ,examine the pipes to see if they have been deformed by over tightening. If pipes are in good condition you can remake the joints ,but judging by your description I would think it more likely that they will be deformed.

 

[Hugh Jaleak]

Can I "half drain" the system so that the water is below the level of the upstairs radiators and towel rail and then use the central heating to at least warm the ground floor of the house and the hot water, or will "bad things happen" if I try to do that?

Do not try to run the heating or boiler without the system being full of water. Draining half of it wont work, the pump will start dragging air in and you risk wrecking both that and the boiler. Switch it off, drain down, fix your leak, then refill and vent before trying to switch it on again.

 

[Avocet]

Thanks everyone. A few photos as requested by The Novice:

Sorry about the Duck tape, it's there to form a temporary "gutter" just to stop the water running back down the 10mm pipe and on to the floor. It's just dripping into a bucket instead. The hexagon on the nut with the 10mm pipe passing through it, is just over 24mm across flats.

Sorry about the Duck tape in the way again! Spanner size on that hexagon nut on the 10mm pipe is 18mm across flats.

 

[Avocet]

Those 10mm copper pipes disappear under the floor. I suspect they'll be soldered to T pieces under there. If the ends are compression fittings and the pipes are distorted, can I cut the top (say) 3" off the copper and joint a new piece on with a compression coupler?

 

[terryplumb]

The TRV will have a set of reducers ,and the other valve probably just 10 mm olive ,judging by the nut sizes. If pipes are deformed , a soldered fitting reducer will sort out the TRV ,and the other valve a new piece of 10 mm copper pipe soldered on with a coupler.
( assuming I am right about the valve tail sizes)

 

[oldbutnotdead]

What did you think would happen when you bent the pipes like that? Next time, shut both valves off, crack the unions to the radiator, drain the radiator, disconnect the radiator unions completely, park it out of the way, tile, rehang.

 

[DP]

Have not read any of the replies above, but my money is on crushed microbore etc.

On the TRV I would be fitting a 15x8 ( or 15x10) adapter and on the lockshield cut the pipe back and redo the joint

See this happen quite a lot

 

[Burnerman]

Unfortunately I think I'd be lifting that board, seeing what was there and starting again......you can always either cap the pipes off or even fit a couple of isolators which will allow you to get the heating back on, and finish that job at your leisure.
John

 

[Avocet]

Thanks all. Been away in Manchester all day today (youngest sprog had something on down there), so I've not done any more on it. Water must be down to the bottoms of the upstairs radiators now because it has stopped leaking! Will drain a bit more off at the boiler tomorrow and take the radiator off. At least I was able to drop into a B&Q today and pick up an assortment of fittings!

The board isn't the floor, the photo is deceptive, it's the top of some boxing that hides the 22mm pipes going to the bath, and the waste coming back from it. Unfortunately, however, the central heating pipes are behind that lot, and they DO come up from under the floor!

 

[Avocet]

What did you think would happen when you bent the pipes like that? Next time, shut both valves off, crack the unions to the radiator, drain the radiator, disconnect the radiator unions completely, park it out of the way, tile, rehang.

No, not "bent the pipes", slackened the unions and swivelled the whole radiator down on to some paint tins. That said, it clearly has disturbed the joints in some way (even if not actually having bent the pipes)! (And yes, the valves were shut at the time).

 

[oldbutnotdead]

No, not "bent the pipes", slackened the unions and swivelled the whole radiator down on to some paint tins. That said, it clearly has disturbed the joints in some way (even if not actually having bent the pipes)! (And yes, the valves were shut at the time).

Ahh fair do's, hadn't realised the rad was mounted with the valves at that jaunty angle. Fun fun fun.....

 

[Avocet]

Thanks again everyone - it now works! I did go with the compression fittings in the end. They're above floor level and behind the boxed-in pipes so I'll be able to keep an eye on them easy enough, and if anything bad happens to the short run between the compression fitting and the bottom of the radiator, it'll be easy to change in future. I fitted a new lockshield valve and TRV too. Interestingly, when it was all off the wall and I could have a good fiddle with the compression fittings where the 10mm pipe went into the TRV and lockshield valve, BOTH were loose! I could twist the 10mm pipe round with my fingers but the nuts were done up super-tight. I'm guessing something bottomed-out on its thread before the olive was being compressed? However, I don't understand why they weren't leaking before? I think I must have stretched something when twisting the radiator down, even though I thought I wasn't applying any load to those joints?

The other thing I noticed, was that the only things that needed bleeding were the bathroom radiator and the towel rail. All the other radiators in the house were full. I'm guessing the bathroom one and towel rail are on a separate circuit? I did get a bit of air out of the various bleed points on the boiler too though.