I didn't replace it twice. There were two PRVs involved in total. The old one and the new one. Simple. I am fairly capable but just in case I always get the wife to switch things on while I watch from a safe distance.
I think we all found French plumbing a bit of a steep learning curve, but Mark is sufficiently cautious to ask around before "plunging in." So long as he confines his activities to downstream of the company tap, his intervention is unlikely to result in disaster and he can always call a plumber if he gets "out of his depth." ;-)
Yeah but if he really knew what he was doing & the principles involved why did he replace it twice? It's a simple unscrew one/ screw on another job to change a relief valve. Bit more to it to fit a PRV where one didn't previously exist. Maybe he can do it! I'm just expressing my opinion that we should be careful when giving advice such as this.
PS Sorry about the "he's" Mark :-)
Rocket science is easy for a rocket scientist. Plumbing is easy for a plumber, some people cannot put a screw in a wall or hang wall paper so unless you know Mark very well it's a risky thing to second guess his level of skill and equipment.
A water leak on the meter side is the water co's problem, after that it's the customers bill and even my inlaws faced a huge bill for a water leak and he is a plumber! (turned out not to be his fault)
I would always be careful in advising folk to fit things like PRV's themselves. It's my firm belief that anyone who has to ask questions such as these does not have sufficient basic knowledge to attempt theses things & is best advised to call in an expert! I don't like the idea of people fitting 'things' 'cos "some bloke on a forum said I should". It's usually a recipe for disaster .
Sorry! I.ve tried to keep out of this conversation but find I'm irresistibly drawn to it so let's clear up a few points which, by the way, have all been covered here before with similar misinformation.
1 bar = approx. 10 m column of water.
The standard galvanised steel electric hot water cylinder is designed to operate at 3 bar static pressure, usually controlled by a pressure reducing valve (PRV). Static pressure is the pressure in the system when no water is being drawn off. Dynamic pressure is the pressure when water is being drawn off. This is always less than static pressure. Not all older systems have a PRV, in fact mine & my neighbours didn't & were operating at 7 bar static pressure. They have a PRV now!. The safety valve on the bottom of the cylinder is designed to discharge at 6 bar which is just below the maximum safe working pressure of the cylinder. When the bulk of the cylinder contents is being heated from cold the starting pressure of 3 bar can rise to above the preset 6 bar of the safety valve & it will drip. It's designed to do this & unlike the English regs which are designed to prevent 'water wastage' is quite normal & in fact keeps the water seal on the discharge drain U bend topped up & stops drain smells coming out of the trap. The manufacturers of the safety valves actually ask the owner to 'exercise' this valve from time to time to ensure it is free to open when needed. To the best of my knowledge there are NO expansion vessels on French systems.
If the cylinder safety valve is leaking when the cylinder is cold & not being heated there can only be two reasons. 1/the water inlet pressure is within the operating limits & the valve is duff. 2/ the inlet water pressure is above the valve's operating limits & it's doing it's job. The same logic can apply to a safety valve which starts to 'leak' when the cylinder is heated if the inlet water pressure & hence cylinder pressure has changed to a higher pressure than previous due to a sticking or dirty PRV & the heating up process starts at a higher initial pressure. My systems inlet pressure will tend to creep up after a year or so due to minute amounts of dirt on the PRV's rubber washer which prevents it closing tightly on the seat. A quick clean always sorts it.
In my previous life as a building services engineer I had reason to investigate similar problems of sudden "bursts" & nearly all were found to be attributable to the Water Authority carrying out a cleaning/replacement programme of old water mains or the modernisation of pumps in non gravity fed systems which led to much improved flow rates & hence dynamic pressures in the mains.
One of the best bits of advice offered here is to measure the water pressure as without this any advice/remedial action is not possible. I have seen a pressure gauge with a rubber thing & jubilee clip which simply attaches to a tap. A cheapo thing like that would be a good starting point :-)
You need to check that you can get adapters to fit your installation and that the manometer has sufficient range for the pressure you have.
Mike, I share your misgivings to an extent, but mismatches seem to be mainly in to do with pipe bores and physical sizes. 3 bars pressure should be the same both sides of the Manche.
Does Screwfix have outlets in France?
I would be very cautious about mixing UK and French plumbing components. Not always compatible...
John, I have looked on Screwfix, which Julia suggested and they sell a pressure reducing valve with a gauge, which seems to kill two birds.
I think it's you that may be barking up the wrong tree Colin. Your explanation didn't include the reason for the un related leaks elswhere.
"The water leaks out when the tank is full, but not hot"
"It has been suggested that the water pressure may have increased, which would also explain some other leaks".
Don't you agree the first step would be to check the pressure with a gauge?
Thank you for your response Colin.
No it doesn't have an expansion vessel. The boiler is about eight years old and has behaved impeccably until now. The valve doesn't drip, it gushes, with cold water. The replacement valve gushes in exactly the same way. Three other items in the cold water system have suddenly sprung leaks at the same time. The conclusion I have drawn, which to me seems logical is that the water pressure has increased. As there doesn't appear to be anything in situ to reduce the pressure, it seems logical to fit one.
I think you may all be barking up the wrong tree!.
Which type of water heater do you have?
Does it have an expansion vessel?
If yes then it may need recharging or replacing.
If no then it will always drip from the PRV. It's designed to.
As water heats up it expands, if it has no room to expand then then the water pressure rises. If it rises above the prv set pressure then the prv will drip. The expansion vessel if fitted will take up expansion and prevent the pressure rising too much. The expansion vessel is just a steel cylinder with a Neoprene diaphragm dividing two sections. One half is connected to the water supply coming in to the water heater , the other is pumped full of air to a specific pressure. Over time this air will escape through the diaphragm and will need to be recharged by someone who knows the correct procedure. Good practice dictates a pressure reducing valve should be fitted before the cylinder as well.
I do agree with you Mike. As I said pressure appears to have increased while the flow rate is unaffected. I'm inclined to test the pressure before effecting any remedial work.
As I said earlier, flow rate and pressure are not the same thing. A partially closed tap or other restriction will reduce the flow rate. But with everything turned off, the pressure will build up and the water should come out with some force when you first open a tap. Have you asked your neighbors if they have had similar problems to yours? I would want to know as much as possible about what is going on before undertaking any work.....
The taps inside the house are brand new.
The electricity is the same. It takes six minutes to boil the kettle where it took three in England. Likewise toast in the toaster takes twice as long. They probably fitted the reducer on the electricity cable instead if the water pipe.
- It all depends on where you are relative to the "chateau d'eau." These 10 metre towers provide the "head" to give 3 bars of pressure at the highest building around, but the pressure it delivers doubles for every 10 metres you go down hill. In hilly areas, your supply may come from a reservoir above the town.
Leisurely flow rates can just be a build up of calcaire on the aerators on the taps, whizz them off and soak in vinegar, test without the aerator whilst they are in soak, at say 7 bar you should get quite wet!
Lucky in that I appear not to have needed one up to now. It's all a bit strange since the flow rate, leisurely at best, seems unaffected by the apparent rise in pressure. It's still working to normal South of France best practice.
In that case then its a pressure reducer as other people have suggested. you must have been lucky not to have needed one before now. When I moved into my house there wasn't one so it may be not that uncommon for one not to be fitted.