No. You must turn off the chauffe eau before draining it.
If your house is wired to normes it will have a separate (& labelled) breaker in the board.
You might have a three position “contacteur heures creuse” too. Moving that to “O” will cut the supply. It will look similar to this…
Thanks Badger, that was what I was worried about. We do have the general cut off similar to what you pictured but I don’t want to do that as it will cut off everything including the heating.
Of the breaker panel alongside it there are several choices labelled, but non of them say anything like chauffe eau. The various choices are Inter Diff General, Prise Cuisine, Machine a laver, VMC Cuisine (is that an extractor?) and Climatisation Cuisine, which is the air to air heater.
I am almost sure that the previous water heater had an off switch, but this one only has the switch for the desired water temperature.
I have left Fran in bed for the time being as she walks only with assistance and must traverse the slippery wet area to get to the bathroom and back again.
Edit:
Just found another switchboard in a different part of the house which does have a switch clearly marked ‘Chauffe Eau - Water Heater’. I have switched that off, it must be the right one we have no other in the house, I just assumed it would be in the kitchen.
I have also switched the water supply off to the heater but, as there is no light or any indication that the electricity supply has been cut, I am nervous about draining down just yet.
Have you looked for any valves to isolate the supply of hot water to the sink either under the sink or by the water heater
If its not leaking when unpressurized I wouldn’t worry about draining it down just yet. If you’re getting a plumber/handy friend to look at it they will need to see exactly where the leak is.
Thanks both, my friend, a ‘handy person’ has just been and managed to pinpoint the leak to a joint in a pipe under the sink. He did try gently to tighten it but no more than that as he didn’t want to do any damage before a real plumber could come.
Not sure if it lessened the flow but we think it has but not stopped it completely. Although there is no off switch or light he proved that the one I found elsewhere has indeed cut the elec. supply. So, the water and the elec to it have both been switched off but we can’t drain the tank presumably because without an inflow there is a vacuum.
As far as we can see there is no valve between the tank and the sink taps so it is now a case of mopping if still necessary till a plumber can come and do the repair properly. Still no word from the insurance company yet, I think it may be the end of the road for them, I already transferred cars and health to Axa a couple of years ago and I feel that this might follow shortly.
Trouble is that, unless they can send one of their contacts, we have no reliable full time plumbers around here. Also a worry is what damage has been done to the floor under the tiles, perhaps why the builder is keeping quiet at the moment.
Finally heard back from the insurers. Not good, they say that they do not have contacts and that we must find our own plumber and pay for the repairs, although they will pay for damage caused on receipt of bills and photos.
Useless, the whole point is that I can’t find a plumber worthy of trust. There is one chance, the English bloke who sorted us very quickly last time but he hasn’t got back to me yet.
The good-ish news is that, although the leak is still dripping, it is much slower and the floor and tiles have begun to dry out. Even the 2 moving tiles have stopped moving. Can’t put the hot water back on yet though, not till it is fixed. If I can’t get it sorted tomorrow I will contact Fran’s aide’s office, they will be back on Thursday morning and will need hot water for what they do. I reckon they may start something moving if they can’t do their job.
Apologies if I am teaching my grandmother and all that David, but have you tried one of the national “plombiers d’urgence” in yellow pages? Obviously you will pay more because they will not be local, but they also have a reputation to maintain so are unlikely to be untrustworthy.
Secondly, I am a complete DIY bodger so anything I recommend is to be treated with great caution, but I have in the past found white PTFE tape incredibly useful for patching up leaking joints and stopping the leak temporarily. If you can get behind the leaking joint, would it be worth wrapping PTFE tape round and round the joint as tightly as you can, extending beyond the joint itself on either side, like a bandage?
Just a thought.
@David_Spardo any chance of a picture of the problem joint? Might be able to make a suggestion. PTFE can only really be used on a thread to help seal the male/female joint. It does not have any mechanical strength to stop leaks
Again, thanks to both of you too. I know about PTFE and have used it before, but as Mark says it is for wrapping round a thread and then screwing over it for a tight seal. Something no doubt the plumber will use when he breaks and remakes the joint.
But sadly @Mark , I have tried but it is just too awkward to get the camera to find the joint which is way up high under the sink and extremely difficult kneeling on one knee at my age while trying to find it on the little screen. If I use 2 knees I topple over, and even having found it and managed to focus, can’t transfer my finger to the button to take the picture. I normally make videos and then take snapshots from them but you don’t get the flash with a video and it is very dark up there. 
As I say, I’m just a bodger but I can assure you Mark I managed to wrap up some pipes in my first flat in Battersea in the 80s (no money for a plumber) until the leaks stopped - they were the joints to the radiators in the lounge and the bedroom. Maybe not much pressure, hence my success? 
You could try just sticking your arm in with finger over the camera button? You might get lucky! Hubby has a cool endoscopic camera thing bought for car repairs bit used quite a bit.
David,
Ok, you’ve turned off the electrical supply.
Usually and hopefully …you should have an isolation valve on the cold water inlet pipe to the water heater aka ballon d’eau chaude. Turn it off to stop water entering the heater, then open the lowest hot water tap in the house, and the kitchen hot water tap, this will lower the pressure and drain some of the system, then open the, see the photo (Sorry, not quite sure what it’s called in English “Security valve”?) this will lower the pressure in the pipe work. Then open the security valve on the hot water tank to either completely drain the whole system or just enough to stop the leak.
That is a good idea. They may have themselves, or know of, suitable handy-people. This sort of small job, less that 2 hours work, falls under the service à la personne category as only requires basic plumbing skills.
So ask them for someone who does petit bricolage et plomberie.
Good idea and @David_Spardo if they use CESU, which most do you get 50% back on your tax return (even if you pay no tax).
Anyone registered as service à la personne qualifies fir the 50% credit impôt even if you pay direct, as long as you get a bill.
Yes, I shut the cold inlet valve before cutting the leccy, it was very stiff but moved easily after a squirt of WD40. At the moment the floor is dry, but I have a barrier of old shirts piled up on the route that the leaked water took and will not disturb that till tomorrow. But a good idea to open the lowest hot water tap (bidet) and then the securite valve to see if I can drain it.
But first tomorrow I will get some PTFE, just in case it works, before moving the shirts and attempting a better seal. Then keep trying for a plumber. If necessary I can ring Christine, Fran’s aide, and see if she can get her office to sort one out for us bearing in mind that it is necessary for Fran’s health.
For washing up and washing Fran this evening I boiled the kettle twice, so no problem in the short term but Christine will want to shower Fran and wash her hair on Thursday morning.
Good you’re getting there!
Teflon tape is rarely the answer unless the couplings requires it to make the seal. If you can get to the leak to apply the tape then you can get to the coupling joints, I’m supposing the leak is coming from the coupling joint and not soldered? Pls send photos. All you probably need to do is to un screw the coupling and replace the washer. Maybe a trip to your local bricolage / Weldom to buy a couple of tools (if you don’t have them) and a pack of washers and with a little on line help from SF can help fix it.
If you need I can walk you through changing a washer via photos or an online feed.
I appreciate what you are saying @Wozza but I don’t think you realise just how old I am. Put it this way, tomorrow I will no longer be in my 70s. 
As I have already said, I can barely see the joint in question without collapsing in a heap on the (wet) floor, much less point a camera at it and take a picture, or a spanner for that matter and, as regards the PTFE, it hasn’t been proved yet if that is going to be even possible.
I have sent a text to the English plumber in a village not too far away to say that the leak seems temporarily stopped, or at least not flooding the floor now, and can only wait for his reply. I know from a mutual friend that he has not gone away but has family there for the, possibly extended, holiday. so perhaps that is the reason for the delay in answering.
Finally, Christine, Fran’s aide will be here at 9 tomorrow expecting to shower her, I am sure that she will be straight on the phone to her office when she finds that she can’t, so maybe things might happen from that direction.
I will try again with the photos though, and I do think from what I have been able to see, is that it is a coupling joint. 
OK, by lying on my back on the now dry floor I waited while a video focused on the joint which I think is the miscreant. Here are 2 screensnaps of it. The middle one of the 3 pipes you can see:
Lying on my back just now and reaching up I can confirm that it has stopped leaking, but maybe that is simply because the feed to the hot water tank is closed, rather than the slight tightening of the nut that my friend did yesterday. But I don’t feel able to reach up with both hands and repair the connection, and to do so without success might leave us in a worse position. So I will leave the hot tank isolated till a real plumber comes along. 
