Replace Your Water Heater? Signs, Age, Repair or Replace

A water heater must be replaced when its tank leaks or rusts, because a holed tank cannot be repaired. It is also better to replace it when faults keep coming back on an old unit. A failed thermostat, heating element or safety valve on a recent tank can usually be repaired.

Is your water heater showing signs of wear in Paris or the inner suburbs? Call +33 1 89 70 15 36 (01 89 70 15 36 from a French phone), 7 days a week, 24 hours a day, or write to us through the contact page or WhatsApp. Many of our plumbers speak English. Our water heater replacement service tells you honestly whether to repair or replace.

A planned replacement is always easier than one forced on you on a Sunday evening with a puddle under the tank. Here are the signs to watch, how to find your unit's age and how to decide.

7 signs a water heater is reaching the end of its life

1. The water is not hot enough any more

The water is lukewarm, uneven, or the tank takes much longer to heat. In Paris, the cause is often a heating element smothered in limescale, sometimes a worn thermostat. On a recent unit, descaling or a new part fixes it. On an old unit that has already been descaled, it is often a sticking plaster. Before concluding, check that the water cools at every tap: if only the shower cools, it is the mixer, not the water heater.

2. Noises while heating

Cracking, popping, bubbling: flakes of limescale coming loose, or a scaled element boiling the water in contact with it. If the noise comes back soon after descaling, the unit is heavily furred up.

3. Rusty or cloudy hot water

Yellowish or brownish hot water while the cold stays clear points to tank corrosion or a spent anode. The anode protects the tank from rust and can be replaced. A tank that is already corroded can split at any time.

4. Damp or a leak around the tank

It all depends on where the water comes from. A leaking safety valve or a loose fitting is easy to replace. Water seeping from the tank, the bottom cover or rust spots means the tank is holed: replacement is the only option. To tell the difference, see our guide water heater repair: no hot water, faults, leaks.

5. Rising electricity use

Your bill is going up with no change in habits? A scaled tank heats for longer for the same result. If your smart meter lets you see hour-by-hour use in your supplier account, check whether the peaks match the tank's heating times.

6. The unit's age

A water heater past the ten-year mark, in water as hard as Paris water, deserves a close eye even if it still works. It may go on for a long time or give up tomorrow. See below how to find its age.

7. Repeated breakdowns

The thermostat last year, the element this year, the safety valve next month: each repair is a new part, but the tank stays the same. At some point the money is better spent on a new, guaranteed unit.

How to find out how old your water heater is

1. Read the rating plate

It is on the side or at the bottom of the tank, sometimes on the wall side. It gives the brand, the capacity in litres, the serial number and often the manufacturing date. Depending on the manufacturer, the date appears:

• in plain form, for example "10/2014";
• inside the serial number, often as year then week (for example "1437" for week 37 of 2014);
• as a letter code specific to the manufacturer.

In a narrow Paris cupboard, a torch and a phone photo save you moving the tank.

2. Ask the manufacturer

If the plate is unreadable, the brand's customer service can find the manufacturing date from the serial number.

3. Look through the flat's documents

Installation manual, old plumber's invoices, documents handed over at purchase or at the start of a tenancy. If you rent, ask the landlord or the letting agency: they often have the installation invoice.

Repair or replace: how to decide

This list sums up common practice among plumbers. It gives pointers, not rules: the real condition of the tank matters more than the year.

• Recent unit, one failed part (thermostat, element, safety valve): Repair
• Unit 7 to 10 years old, one or two signs: Get a diagnosis before deciding
• Unit over 10 years old with a fault needing a major part: Usually replace
• Leaking tank or rusty water: Replace without waiting
• Third fault in a short time: Replace

Three questions to ask yourself with the plumber:

1. Is the tank sound? If it leaks or rusts, the question is settled.
2. How does the repair cost compare with a new unit fitted? An expensive repair on an old unit is rarely a good bet.
3. Have I already repaired this tank recently? If so, the next fault is probably not far off.

For amounts, see our prices. A good plumber tells you clearly when a repair is enough.

Common repairs, and what they involve

• Thermostat: water and power off, cover removed, part replaced, tested. A short job when the tank is accessible.
• Heating element: the tank is fully drained, the flange removed, the element extracted (often stuck in scale), the bottom of the tank cleaned, the anode checked, and everything refitted with a new seal. A chance to switch from an immersion element to a ceramic one, better suited to hard water, if the model allows.
• Safety valve: the part on the cold water inlet is replaced and the drain checked. See also our article on a dripping safety valve.
• Anode: checked during descaling, replaced if badly worn.
• Descaling: draining, cleaning the element and the tank. On a unit in good condition, it often brings a clear improvement.

What makes a replacement harder in a Paris flat

• Access: tank in a narrow cupboard, above the toilet, in a false ceiling or high up in a corridor. Panelling sometimes has to come off. Send photos of the location before the quote.
• Weight: a full tank weighs the unit plus the water, one kilo per litre. On a plaster block wall or an old floor, the fixing and support must be suitable.
• Stairs: in a building with no lift or a tiny one, the tank goes up the stairs. The building rules may also set hours for works.
• Electrics: an old fuse box may need the water heater circuit upgraded to the NF C 15-100 standard. A serious plumber flags this in the quote, before starting.
• Pressure: some older buildings have low or, on the contrary, high water pressure. A pressure reducer may help, and the safety valve must be suitable.

Plan the replacement rather than suffer it

If your water heater is past ten years or shows several of the signs above, get ahead:

1. Note the capacity, dimensions and location of the current unit.
2. Think about the number of occupants and your habits: a tank too small leaves you without hot water, a tank too large heats water for nothing.
3. Ask for a quote that itemises the unit, removal and disposal of the old one, a new safety valve and the connections.

Choosing the model, the capacity and the fitting steps are covered in our electric water heater installation guide.

Tenant or landlord: who replaces it?

If you rent, tell your landlord or letting agency in writing at the first signs, with photos. Routine upkeep is generally the tenant's job and replacing a worn-out unit the landlord's. Your lease and your landlord are the reference: do not have the unit replaced without their agreement.

Frequently asked questions

How long does an electric water heater last?

It depends mostly on water hardness and maintenance. In Paris, where the water is hard, a tank that is never descaled ages faster. Rather than a figure, go by the condition of the tank, how often it breaks down and the signs above.

Can a leaking water heater tank be repaired?

No. A tank holed by corrosion cannot be repaired durably. Only the safety valve, fittings and seals can be repaired.

Can descaling avoid a replacement?

On a unit in good condition, yes: it often brings a clear improvement and protects the element. On a unit at the end of its life, the gain is temporary.

Should the safety valve be changed with the water heater?

Yes, a new safety valve is fitted with every new water heater. Have the flexible hoses and fittings checked too.

Is there financial aid to replace a water heater?

For a repair or a standard electric tank, generally not. For some more efficient equipment, such as a heat pump water heater, aid may exist under conditions, provided the installer is RGE for that work. Our article on plumber certifications in France explains how to check.

Get your water heater checked

Réseau Tubulure works in Paris and the inner suburbs (92, 93, 94), 7 days a week, 24 hours a day, to repair or replace your water heater. Many of our plumbers speak English.

• Phone: +33 1 89 70 15 36 (01 89 70 15 36 from a French phone)
• Form: contact us
• WhatsApp: from the button on the site

See our water heater replacement service.