French electric hot water tank, in its final days

[Drippingmore]

Helping a friend at a small house in France.

Please advise about this thing on the bottom of the electric hot water tank.

The cold water comes in from the right, and I presume the TOP half is a pressure reducer, for the water to then go upwards into the tank.

I also presume the BOTTOM half is a pressure safety valve, if and when the water in the tank expands.

(I am used to seeing an expansion tank attached at this point in the UK.)

Anyway, yesterday I turned the bottom tap a bit anti-clockwise as a routine test, BUT it will not go back again, and water continually flow down the overflow below. No doubt the limescale has got to the thing.

We then turned the water off entirely and headed to Blighty.


This WHOLE system will be replaced in the summer, but we would be willing to buy a replacement unit for the next few months. Or shall I take the plastic knob off and try using grips to turn clockwise?


Is there a French 'Plumbers-R-Us' that might STILL sell an exact replacement?


By the way, I assume the inlet pipe is 14mm, if you are able to judge it from the photo.


As Del Boy would say, "Mange tout, mange tout".

 

[snowhead]

The combination valve is made by Caleffi and is an isolating, check valve and pressure relief valve, newer version below,

There should be an expansion vessel somewhere.

Hydraulic safety group for hot water storage heaters, with shut-off valve and controllable check valve. | Caleffi S.p.a.

www.caleffi.com

The way it's designed and fitted looks to be a perfect trap for scale in the pressure relief valve.

 

[Frelon]

Expansion vessel is not needed with these small water heaters - the tundish is built into the valve and allows water to escape when it is heated and expands! When the water reaches the set temperature the dripping stops. This from 12 years living in France with this type of water heater (30 litres).

Anyway, yesterday I turned the bottom tap a bit anti-clockwise as a routine test, BUT it will not go back again, and water continually flow down the overflow below. No doubt the limescale has got to the thing.

Yes, this happens, especially in hard water areas and lime scale builds up aroud this (Groupe de sécurité hydraulique pour chauffe-eau)

As you may have observed, French plumbing uses different size copper tubing - British plumbing is not compatible! 12mm, 14mm and 16mm are common sizes for inside the house!

 

[Drippingmore]

And both UK and France use 22mm and 28mm, I think?

 

[Frelon]

Yes, 22mm and 28mm, but French copper tubing is thicker than UK stuff!

 

[Drippingmore]

You say "the tundish is built into the valve and allows water to escape when it is heated and expands!"

I have fitted a UK 80-litre Ariston Eco at home, with an expansion tank alongside it.

In France, would a 80-litre Ariston Eco come without a tank? Don't the French bother? (!)

 

[Frelon]

In France, would a 80-litre Ariston Eco come without a tank? Don't the French bother? (!)

You would have to ask a French Plombier that?