My Veito water heater gives no hot water at all, the water runs cold — why?

Check these in order: 1) The breaker may have tripped — check the fuse box. 2) Water flow may be insufficient; central models (Blue S, Blue E, Flow E7 / E9, Speed-E) need at least 3 liters per minute to activate, so open the tap fully. 3) The tap aerator, the unit's inlet filter or the shower head may be clogged; remove and clean them. 4) On shower-type units (V1100 / V1200 / Glow), if the lights come on and go off immediately when you open the water, the shower head or water outlet is most likely blocked. 5) If a central unit never activates despite having power, there may be a bypass in the plumbing — if hot water still flows from the tap after you close the unit's water valve, a bypass exists. If the issue continues after fixing these, the heating element or thermal protection is faulty and authorized service is needed.

My Veito instant water heater doesn't heat the water enough, it comes out lukewarm — what should I do?

Most often the flow rate is too high; the unit can't keep up heating fast-flowing water. Reduce the tap flow slightly and set the unit to 40 °C. Because incoming water is colder in winter, the amount that can be heated per minute is limited: about 8 liters for Blue S, about 4.5 liters for Flow E9 and Speed-E, about 4 liters for Flow E7, and about 4 liters for shower-type models (Glow, V1100, V1200). To see the flow rate, press the + and − buttons on the display at the same time while water is running on Flow E7 / E9; on Blue S, switch the breaker off and on, and the flow rate shows on the display for the first 10 seconds. If the water is still lukewarm after reducing the flow, and the unit fills all power indicators at 40 °C, the heating element or power board is faulty; authorized service will take a measurement.

My Veito gives alternating hot and cold water, the temperature is inconsistent — what's the cause?

Set the unit to 40 °C and try again; this resolves most cases. When a higher temperature is selected, the unit overheats, trips its self-protection and cuts out, causing the water to alternate hot and cold. If you're mixing the hot water with cold at the tap, less water passes through the unit and the same result occurs — try using the hot tap alone. It can also happen if water pressure fluctuates or the inlet filter / flow sensor is dirty; clean the inlet filter, and if that doesn't fix it, have the service check the flow sensor.

Why does the breaker or residual-current device trip when I turn on the Veito water heater?

When it trips tells you the cause; there are three cases. 1) If the RESIDUAL-CURRENT DEVICE trips the instant you open the water, the unit's heating element is leaking current to the body; the device trips to protect you, this won't clear until the element is replaced, and it's a job for authorized service. 2) If a REGULAR BREAKER trips 3–5 minutes after the unit starts running, the overcurrent breaker it's connected to is undersized; a quality breaker matching the model should be fitted: 32A for shower-type models (V1100 / V1200 / Glow) and Flow E7, 40A for Flow E9, and 3×32A for Blue S / Blue E. 3) If the breaker trips about 10 seconds after opening the water (Blue S / Blue E), the unit's electronic board is faulty; turn off the unit's power and water and call authorized service. Try resetting the breaker once; if it trips again, don't keep forcing the unit to run.

My Veito water heater doesn't work at all, the display doesn't light up — what's the solution?

First check the power supply: the breaker may have tripped, or a connection may be loose. Turn the unit off and back on after 1 minute. On shower-type models, it's also common for the hot–cold water hoses to be connected in reverse, or for the internal thermal circuit breaker to have opened due to overheating. If the display still doesn't light up while power is present, the board or an internal connection may be faulty; a check by authorized service is needed.

Water is dripping / leaking from my Veito water heater — what should I do?

It's usually caused by the inlet/outlet fitting connections or gaskets; check that the connections are tight. If water is coming from the unit's body, there may be a leak at an internal gasket or around the heating element. Since water and electricity together are dangerous, turn off the unit's power and water and contact the service.

Does a Veito instant water heater need limescale maintenance?

Not for wire-element models. Veito heats water instantly without storing it in a tank. All models except V1200, V1100 and Glow use a wire heating element; these units barely accumulate limescale and need no periodic descaling. The older-generation classic-element V1200, V1100 and Glow are affected by hard water. The only parts that can clog over time are accessories like the tap aerator, the unit's inlet filter and the shower head; if the water flow weakens, remove and clean these first.

There's crackling / hissing / a burning smell coming from my Veito water heater — is it dangerous?

A light crackling from the heating water, or hissing from air in the line, is usually harmless; running the water for a few minutes to purge the air from the line helps. On the Blue S and Flow series, the unit may show an E05 / E5 warning and stop when it detects an air bubble — opening and closing the tap a few times is enough. A faint dusty smell on first use is also temporary. However, if a burning or plastic smell persists, this signals an electrical problem; turn the unit off without running it again and contact service immediately.

Water flows weakly from my Veito water heater, the flow rate is low — how do I fix it?

The blockage is usually in an accessory, not inside the unit itself: the tap aerator, the unit's inlet filter (strainer), or the shower head gets clogged with sediment; remove and clean them. Mains water pressure may also be low. On Flow E7 / E9, the water inlet also has a flow restrictor fitted from the factory; if your water pressure is low, this part can prevent the unit from activating at all and needs to be removed. If it still doesn't improve, contact service to check the flow sensor.

What does the E1 / E2 / E3 error code on the Veito display mean?

Codes are E01–E06 on the Blue S, and E1–E8 on the Flow E7 / E9 and Speed-E; since the Blue E has no display, an error LED on the board lights up instead of a code. Meanings: E1 / E01 inlet water temperature sensor not detected (technician) · E2 / E02 outlet water temperature sensor not detected (technician) · E3 / E03 inlet water temperature too high, usually from a solar water system; a thermostatic mixing valve should be used · E4 / E04 inlet water too cold, freeze risk; shut off the unit's water, switch off its breaker and drain the water inside · E5 / E05 air-bubble detection active; open and close the hot water tap a few times · E6 / E06 outlet water temperature too high, the power board needs checking / replacing · E7 low input voltage · E8 high input voltage (both caused by the mains supply or wiring). Once the issue clears, the warning disappears on its own and the unit resumes where it left off.

My central Veito unit has power but never activates — what is a bypass, and how do I check for one?

If a central unit (Blue S, Blue E, Flow E7 / E9, Speed-E) never activates despite having power, there are three possible causes: the flow sensor is faulty, too little water is coming through, or there is a bypass in the plumbing — meaning hot and cold water are mixing somewhere. You can test for a bypass at home: close the unit's water valve (usually located under the unit's cover); with the valve closed, no water at all should flow from the hot tap. If water keeps flowing, a bypass exists and its location must be found and eliminated. The most common source is a thermostatic mixer tap that blends hot and cold water to give a constant temperature. If you have solar water heating or a thermosiphon: in a correct setup, the incoming hot water is routed through a thermostatic (NIKS) mixing valve and limited to a maximum of 50 °C, allowing the two systems to work together; without a mixing valve, leaving both systems' valves open creates a bypass, and the valve of the unused system must be closed.

How many liters of water per minute, at minimum, does a Veito unit need to run?

Central models (Blue S, Blue E, Flow E7 / E9, Speed-E) need a flow of at least 3 liters per minute to activate; below that, the unit won't run. When power is first applied, the unit shows the flow rate on the display for 10 seconds before activating — keep the tap open during these 10 seconds. If you see a value below 3 on the display, there are three possibilities: your water pressure is low, the filters and taps are clogged, or there is a bypass in the plumbing. To see the flow rate, press the + and − buttons at the same time while water is running on Flow E7 / E9; on Blue S, switch the breaker off and on, and it shows on the display for the first 10 seconds.

Faults and Fixes · Every Veito Model · Deniz Teknik

General faults and simple fixes all models

If you do not know your model, start here — these problems are common to most Veito instant water heaters. The line under each heading gives the short answer; tap the heading for the detail.

🚿The unit does not work / no hot water at allCheck the fuse first, then the flow rate and the inlet filter.▾

Possible causes

No power, or the fuse has tripped
Flow too low — central units need at least at least 3 litres per minute before they switch on
The hot and cold connections are the wrong way round
The thermal cut-out inside the unit has tripped because of overheating
The heating element, flow sensor or electronic board has failed

Try this at home

Check the consumer unit (distribution board)
Open the tap fully — is the flow strong enough?
Close the unit's inlet filter, the tap aerator and the shower head — remove and clean them
On shower units: if the lights come on and go straight out when you open the water, the shower head or the water outlet is blocked

A service call is needed

The heating element, flow sensor, thermal cut-out and electronic board are diagnosed by measurement
⚠ Reaching the thermal cut-out's reset button means taking the unit's cover off — do not do this yourself, live electrical parts are underneath

🌡️The water is lukewarm — it doesn't get hot enoughClose the tap a little — less water comes out hotter.▾

Why it happens

An instant water heater heats the water as it passes: the faster it flows, the less it warms up. In winter the incoming water is very cold, which makes the effect stronger.

Your model's capacity (in winter, per minute)

Blue S — 8 litres
Flow E9 — 4.5 litres
Flow E7 — 4 litres
Glow · V1100 / V1200 — 4 litres

Try this at home

Close the tap to bring the flow down to the figure above
Don't use two outlets at the same time
Set the unit to 40 °C— on the Blue E turn the knob to the saucepan mark (≈42 °C)
Clean the inlet filter and the shower head

Flow E7 / E9 — checking the flow rate

With hot water running, press the + and − buttons together on the display → the flow rate appears
If the temperature light on the display is flashing , the unit cannot reach that temperature — close the tap a little

Blue S — checking the flow rate

Close the unit's switch the fuse off and on again; for the first 10 seconds the display shows the flow rate
If all the power bars under the display are full , the unit cannot deliver that temperature — close the tap a little

A service call is needed

If closing the tap does not help either, the heating element must be measured

♨️The water keeps going hot then coldTurn the temperature down to 40 °C — that solves most cases.▾

Possible causes

At a high setting the unit overheats, goes into self-protection and keeps switching on and off
The flow — especially the hot water flow — is too low
The inlet filter is blocked
Mains water pressure or voltage is fluctuating
There is an air bubble in the system (the unit detects it and stops; it usually clears by itself)

Try this at home

Set the unit to 40 °CSet the unit to 40 °C
Use one tap at a time
Clean the inlet filter
Open and close the hot tap a few times to purge the air from the line
On stepped (mechanical) models, drop one power stage

A service call is needed

Cleaning or replacing the flow sensor
If the pressure is very low, the plumbing may need adjusting

⚡The breaker or RCD tripsWhen it trips tells you why — immediately, after 10 seconds, or after minutes?▾

⚠️

Safety warning: Try resetting the fuse once; if it trips again, do not insist on running the unit and never touch it with wet hands.

The RCD trips as soon as you turn on the water

The heating element is leaking to earth. It cannot be fixed without replacing the element — a job for the authorised service.

The FUSE trips 3-5 minutes after the unit starts running

The circuit breaker the unit is connected to is undersized. Fit a quality breaker matching your model: quality breaker must be fitted:
Shower-type units (V1100 / V1200 / Glow) and Flow E7 → 32 A
Flow E9 → 40 A
Blue S / Blue E → 3×32 A

The FUSE trips 10 seconds after you turn on the water (Blue S / Blue E)

Close the unit's electronic board is faulty. Switch off the unit's power and water and call the authorised service.

🔀Central unit will not switch on — bypassIf hot water still flows with the unit's valve closed, there is a bypass in the plumbing.▾

On central-system units (Blue S, Blue E, Flow E7 / E9), if there is power but the unit will not switch on, there are three causes: 1) the flow sensor has failed · 2) the incoming flow is too low · 3) there is a bypass in the plumbing — hot and cold water are mixing somewhere.

Bypass test (you can do this at home)

Close the unit's water valve. If you cannot see the valve, it is most likely under the unit's cover.
With the valve closed, no water at all should come out of the hot tap.
If water keeps flowing, hot and cold water are mixing somewhere in the plumbing — that is the bypass and it must be found and eliminated.

If there is a solar system or a storage heater

With a correct installation they can work together: the hot water coming from the solar system is passed through a thermostatic (NIKS) mixing valve and no more than 50 °C is limited, the Veito unit accepts this as inlet water and the two systems work together — if the water is already hot the unit does not switch on, and when the heat is not enough it tops it up.
A wrong installation creates a bypass: if there is no mixing valve and both systems are left with their valves open, the hot water circulates in the pipework without passing through the unit; the unit sees no flow and never switches on. In that case the valve of the system you are not using must be closed.
In short: if a mixing valve is fitted the two can stay together; if not, only one system may be open at a time — either the solar system, or the storage heater, or your Veito unit. To switch back to the Veito unit, close the solar valve and open the unit's valve; the other way round works the same.

Thermostatic mixer tap (the most common cause)

Classic thermostatic bathroom mixer tap — **Thermostatic bathroom mixer tap (classic)** — the knob is marked **20-30-38-40** and has a red safety button.

Thermostatic bathroom mixer tap with digital display — **Thermostatic bathroom mixer tap (newer model)** — with a digital display showing the temperature. It does the same job.

Kitchen sink with mixer tap — **Kitchen sink mixer tap** — a single-lever mixer mounted on the sink; the lever blends hot and cold water.

If the bathroom or kitchen has a thermostatic mixer tap that blends hot and cold water to a fixed temperature, this is usually the main source of a bypass.
On such a tap the temperature setting must always be left either fully hot or fully cold . If it is left in the middle and the outlet is closed, hot and cold water mix inside the tap.
Then, when you open hot water at another tap, the water travels through that mixer instead of through the unit; because the unit never switches on, people think "the unit is not heating" .

🔥Burn marks or a burning smell inside the unitIf you see burn marks, do not run the unit at all.▾

⚠️

This is a safety issue. If the outer cover has been removed and you see any burn marks inside, then switch off the unit's power and water and call the service immediately. Do not try to run the unit again.

Why it matters

Burn marks mean a connection is overheating or the board has failed; carrying on using it leads to worse damage

A service call is needed

The burnt part and its cause must be identified by the authorised service

Sounds and smells that are normal

On first use a faint smell from warming dust and a crackle from the heating water are normal and pass
For hissing caused by air in the line, run the water for a few minutes
But if a burning or plastic smell persists it is an electrical fault — switch the unit off

💧Leaking or drippingDripping at a joint means a seal; leaking from the body means service.▾

Possible causes

The inlet/outlet connection seals have loosened
The unit's inner chamber is leaking
Excessive pressure

Try this at home

Check the compression fittings by hand
If the drip is coming from a fitting, the gasket can be renewed

A service call is needed

If the leak is very small (drip by drip): you can keep using the unit carefully until the service arrives
If the leak is significant: switch off the unit's power and close the water valve, then wait for the service

🚱Weak flow / very little waterThe blockage is not inside the unit, it is in the accessories.▾

Where it blocks

The shower head (most often on shower-type units)
The tap aerator
The plastic filter at the unit's inlet

Try this at home

Remove and clean all three; if limescaled, soak them in vinegar
If mains pressure is low the unit may not switch on

Note

Veito does not store water; the wire-element models — all except the V1200, V1100 and Glow — need no descaling. Blockages happen in the accessories, not inside the unit.

🔢There is a fault code on the display (E01-E06 / E1-E8)Find what the code means for your model here.▾

When the unit stops heating because of a fault it reports it with a code on the display (on the Blue E, with the fault LED on the board). Once the problem clears the warning disappears by itself and the unit carries on. The tables below are taken from the Veito user manuals.

Try this first

Switch the unit off and on again after 1 minute (reset)
Open the tap and make sure the flow is sufficient
If the code comes back, look up its cause in the table below

🔢Blue S — E01-E06The code appears on the display.▾

Code	Cause	Fix	Who?
E01	The inlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
E02	The outlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
E03	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
E04	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
E05	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
E06	Outlet water temperature above 70 °C.	Replace the power board.	Technician

🔢Blue E — fault LEDIt has no display, so the LED on the board lights up instead.▾

LED	Cause	Fix	Who?
Red-blue LED	The inlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
Flashing red	The outlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
Flashing magenta	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
Steady blue	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
Flashing blue	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
Steady red	Outlet water temperature above 70 °C.	Replace the power board.	Technician

🔢Flow E7 / E9 — E1-E8The code appears on the display.▾

Code	Cause	Fix	Who?
E1	The inlet water temperature sensor is not detected.	Check the sensor and its cable.	Technician
E2	The outlet water temperature sensor is not detected.	Check the sensor and its cable.	Technician
E3	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
E4	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
E5	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
E6	Outlet water temperature is high.	Probable board fault — needs checking.	Technician
E7	Low input voltage.	Caused by the mains supply; the fault in the electrical installation must be put right.	Technician
E8	High input voltage.	Caused by the mains supply; the fault in the electrical installation must be put right.	Technician

⚠️

Important: Because electricity and water are involved, don't take the cover off or touch electrical parts yourself. The "try this at home" steps above are safe; beyond that you need the authorised service. Letting an unauthorised person open a unit under warranty can void that warranty.

Veito Blue S

380 V21 kWCentralDigital temperature control

Top-of-the-range, high-power (380V · 21 kW) central-system model. It can feed the bathroom and the kitchen at the same time; the temperature you want is set on the display digitally and applied.

The water keeps going hot then cold

Set the unit to 40 °Cand try again. At a higher setting the unit overheats, goes into self-protection and switches off, so the water alternates hot and cold. For everyday use 40 °C is more than enough.

The unit heats too little

If the unit is set to 40 °C and below the display all ten power bars are full, it means the unit cannot deliver that temperature. There can be two reasons: 1) too much water is passing through · 2) the heating element is faulty. The Blue S can heat about 8 litres of water per minute; first try closing the tap a little. If that does not help, the authorised service must measure the element.

The fuse trips 10 seconds after you turn on the water

The electronic board is faulty. Switch off the power and the water supply to the unit and call the authorised service.

The display shows 0.0

When the power first comes on and the unit is about to run for the first time, it shows for 10 seconds how much water is flowing, then it switches on — leave the tap open for those 10 seconds. To switch on it needs at least 3 litres of water per minute; below that the unit will not run. If the display shows less than 3, there are three possibilities: 1) your water pressure is low · 2) the filters, valves or taps are blocked · 3) there is a bypass in the plumbing — cold water is mixing into the hot water line. To see the actual flow, switch the fuse off and on again; for the first 10 seconds the display shows the flow rate — very useful in winter.

🔢 Fault codes (E01-E06) ▾

When the unit stops heating because of a fault it tells you. Once the problem clears, the warning disappears on its own and the unit carries on. The table below is taken from the Veito user manual. The Blue S shows the code on the display .

Code	Cause	Fix	Who?
E01	The inlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
E02	The outlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
E03	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
E04	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
E05	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
E06	Outlet water temperature above 70 °C.	Replace the power board.	Technician

Download the user manual (PDF)

📄 User manual (PDF)

↑ Back to the faults common to all models

Veito Blue E

380 V21 kWCentralNo display

The display-free member of the Blue family; same power as the Blue S, the only difference is that the temperature is set not on a screen but with the rotary knob on the body instead of a touch screen. In case of a fault, instead of a code the fault LED on the board lights up.

The water keeps going hot then cold

Turn the temperature knob saucepan mark and try again. At a higher setting the unit overheats, goes into self-protection and drops out, so the water runs hot and cold in turns. If the temperature does not change at all the knob may have come loose: press it in and turn it fully left or fully right as far as it goes, then bring it to the position with the pot symbol.

The temperature knob does nothing / the temperature will not change

The Blue E's rotary temperature knob does not always engage on the first try. Press the knob in and turn it fully left or fully right , then leave it at the 1 o'clock position — the mark with the saucepan symbol on it. That is the ideal working setting, about 42 °C.

The fuse trips 10 seconds after you turn on the water

The electronic board is faulty. Switch off the power and the water supply to the unit and call the authorised service.

🔢 Fault warnings (fault LED) ▾

LED	Cause	Fix	Who?
Red-blue LED	The inlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
Flashing red	The outlet water temperature sensor cable has come loose.	Check the sensor and its cable.	Technician
Flashing magenta	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
Steady blue	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
Flashing blue	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
Steady red	Outlet water temperature above 70 °C.	Replace the power board.	Technician

Download the user manual (PDF)

📄 User manual (PDF)

↑ Back to general faults

Veito Flow E9 / Flow E7

220V9 / 7 kWCentralDigital temperature control

Current-generation models with a digital display; they switch on automatically with the water flow, and the temperature is set with the + and − keys on the display. Flow E9 (9 kW) has enough output for several outlets, bathroom included; Flow E7 (7 kW) suits a single bathroom or kitchen better. They work in exactly the same way.

The display shows 0.0

The temperature light is flashing / it does not heat enough

In winter the Flow E9 can heat about 4.5 litres, and the Flow E7 about 4 litres of water per minute; above that they cannot reach the temperature you set. Close the tap to bring the flow down to that figure. To see the actual flow, with the tap running press the unit's + and − buttons together — the flow screen appears. If the temperature on the display is steady , the unit can deliver that temperature; if it flashes , it is telling you it cannot reach that temperature. The usual working temperature is 40 °C.

Weak water flow

First check the same things as on other models: the mains water pressure may be low · the tap's aerator, the unit's inlet filter or shower head may be blocked — remove and clean them. There is one more reason specific to this model: at the unit's water inlet there is a factory-fitted flow restrictor . If your water pressure is low, this part can stop the unit from switching on at all and has to be removed. To remove it, shut off the inlet water, take off the front cover and turn the plug on the water inlet fitting in the loosening direction — in the seat the inlet water strainer and flow restrictor sit side by side.📷 A photo showing how the flow restrictor is removed will go here

The unit does not work

If the display is completely dark: check the fuse first; if the fuse is on and the display still does not light up, you need the authorised service. If the display works but the unit does not switch on: the flow may be too low · the hot and cold connections may be reversed · the flow sensor may have failed (a service job).

🔢 Fault codes (E1-E8) ▾

Code	Cause	Fix	Who?
E1	The inlet water temperature sensor is not detected.	Check the sensor and its cable.	Technician
E2	The outlet water temperature sensor is not detected.	Check the sensor and its cable.	Technician
E3	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
E4	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
E5	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
E6	Outlet water temperature is high.	Probable board fault — needs checking.	Technician
E7	Low input voltage.	Caused by the mains supply; the fault in the electrical installation must be put right.	Technician
E8	High input voltage.	Caused by the mains supply; the fault in the electrical installation must be put right.	Technician

Download the user manual (PDF)

📄 User manual (PDF)

↑ Back to general faults

Veito Speed-E

220V9 kWCentralDigital temperature control

Technically the Speed-E is exactly the same unit as the Flow E9 — same power, same operating principle, same fault symptoms and same fixes. The only difference is how it is sold: the Flow E9 is sold with installation included, while the Speed-E is an export product and its installation is charged.

The display shows 0.0

The temperature light is flashing / it does not heat enough

In winter the Speed-E can heat about 4.5 litres of water per minute; above that they cannot reach the temperature you set. Close the tap to bring the flow down to that figure. To see the actual flow, with the tap running press the unit's + and − buttons together — the flow screen appears. If the temperature on the display is steady , the unit can deliver that temperature; if it flashes , it is telling you it cannot reach that temperature. The usual working temperature is 40 °C.

The unit does not work

🔢 Fault codes (E1-E8) ▾

Code	Cause	Fix	Who?
E1	The inlet water temperature sensor is not detected.	Check the sensor and its cable.	Technician
E2	The outlet water temperature sensor is not detected.	Check the sensor and its cable.	Technician
E3	Inlet water temperature too high (may come from a solar water system).	If there is a solar system, check the inlet water temperature; fit a thermostatic mixing valve if needed.	Customer
E4	Inlet water temperature too low (risk of freezing).	Shut off the water to the unit at once, switch off its fuse and drain the unit by opening the hot tap. You can restart it once the freezing risk has passed.	Customer
E5	The air-bubble detection system has activated.	Open and close the hot tap a few times to purge the air from the system.	Customer
E6	Outlet water temperature is high.	Probable board fault — needs checking.	Technician
E7	Low input voltage.	Caused by the mains supply; the fault in the electrical installation must be put right.	Technician
E8	High input voltage.	Caused by the mains supply; the fault in the electrical installation must be put right.	Technician

Download the user manual (PDF)

📄 User manual (PDF)

↑ Back to general faults

Veito Glow

220V8 kWMechanicalShower unit

The shower unit that replaced the V1100. It fits inside the shower enclosure and supplies that shower only; a shower head and hose come in the box.

The RCD trips as soon as you turn the water on

It means the heating element is leaking to earth. It will not be fixed without replacing the element — a job for the authorised service. (A fuse that trips after a few minutes is a different problem, explained below.)

The lights come on when you open the water, then go out immediately

The shower head or the water outlet is blocked. Too little water flows, so the unit cannot stay switched on. Remove and clean the shower head and the water outlet.

The unit does not work at all, no lights

Check in this order: 1) the flow may be too low — open the tap fully · 2) the hot and cold hoses may be connected the wrong way round · 3) the fuse in the consumer unit (distribution board) may have tripped · 4) the thermal cut-out inside the unit may have tripped due to overheating; resetting it means opening the cover and pressing the reset button. ⚠ Do not do this last step yourself — the cover exposes live electrical parts; call the service instead.

Weak flow / water comes out too hot

With less water passing through, the unit overheats it. There are two causes: the plastic inlet filter is dirty, or the shower head is blocked. Remove and clean both.

The fuse trips 3-5 minutes after the unit starts running

The overcurrent fuse the unit is connected to is undersized; 32 A fuse must be fitted instead. (This is the ordinary fuse, not the RCD in the first item.)

Not heating enough (especially in winter)

Shower-type units can heat about 4 litres of water per minute. In winter the incoming water is very cold, so if even stage 3 is not enough, close the tap a little to reduce the flow — the water will come out hotter. If it still seems wrong after trying that, request a service call.

📄 User manual (PDF)

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Veito V1100 / V1200

220V8 kWMechanicalShower unit

The previous generation of shower-type instant water heaters. Sturdily built; they work almost exactly like the Glow and have the same faults. The most common problem comes from the heating element. (Note: the V1200 was also sold as Lux for a while; it is the same unit.)

The RCD trips as soon as you turn the water on

The lights come on when you open the water, then go out immediately

The shower head or the water outlet is blocked. Too little water flows, so the unit cannot stay switched on. Remove and clean the shower head and the water outlet.

The unit does not work at all, no lights

Weak flow / water comes out too hot

With less water passing through, the unit overheats it. There are two causes: the plastic inlet filter is dirty, or the shower head is blocked. Remove and clean both. V1200 only: the rotary knob underneath the unit is the flow control valve; turning it clockwise restricts the water. Turn it anticlockwise as far as it goes.

The fuse trips 3-5 minutes after the unit starts running

The overcurrent fuse the unit is connected to is undersized; 32 A fuse must be fitted instead. (This is the ordinary fuse, not the RCD in the first item.)

Not heating enough (especially in winter)

📄 User manual (PDF)

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Veito Flow / Flow S (older range)

220V7 / 9 kWCentralMechanicalOlder range

The mechanical models of the previous generation; production has stopped and Flow E9 / E7 have taken their place. Power and features are identical to their electronic counterparts — the only difference is a mechanical step switch instead of a display. They are still in use, so we still service them; where it makes sense we suggest moving to a newer model.

Not heating enough

There can be two causes: 1) the heating elements are faulty — the authorised service will confirm this by measurement · 2) in winter too much water is passing through. These units can heat about 4.5-5 litres of water per minute; in winter close the tap to reduce the flow.

The fuse trips

This is the ordinary (overcurrent) fuse. It must be replaced with a good-quality 40 A fuse.

Water keeps going hot then cold

If the flow — especially the hot water flow — is too low, the unit overheats and protects itself, switching on and off repeatedly. Drop the unit one power stage, or increase the water flow. If the flow is weak the inlet filter may be blocked; check that first.

The unit does not work

There are two things you can check yourself: if the flow is weak, the unit's inlet filter, and the electrical fuse. If both are fine, you need to call the authorised service.

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Something wrong with your Veito instant water heater?

My Veito water heater is not working — what should I check first?

Pick your model

General faults and simple fixes all models

Veito Blue S

Veito Blue E

Veito Flow E9 / Flow E7

Veito Speed-E

Veito Glow

Veito V1100 / V1200

Veito Flow / Flow S (older range)

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