ENGLISH

9

www.timberk.

com

i

nstant 

water heater

6. To switch off the appliance, turn the power control knob counterclock-
wise and close the cold water feed valve.

9. 

TROUBLESHOOTING

Table 3
Possible failures and methods for their elimination

8. 

MAINTENANCE

During use of the water heater, scale may appear in nozzle openings of 
the shower spout. This reduces efficiency of heating, deteriorates water 
spraying, and increases water pressure in the heating vessel. For preven-
tion of such phenomena, it is necessary to periodically clean the nozzle 
using household chemical agents and soft brushes. Do not use abrasive 
cleaning substances and inappropriate chemical agents.
a) Outer care:
- Switch off the appliance and allow it to fully cool down.
-  Clean  the  outer  surface  of  the  appliance  enclosure  using  a  slightly 
moistened soft cloth and then wipe it dry. Do not use abrasive cleaning 
substances.
b) Filter cleaning:
If water flow rate from the heater decreases, it is necessary to clean the 
coarse filter installed at the cold water inlet to the water heater. Use the 
following procedure:
- Switch off the appliance and allow it to fully cool down.
- Shut off cold water feeding.
- Unscrew the cold water feed hose from the water heater, remove the 
coarse strainer and flush it under a jet of flowing water.
- Restore the inlet connections in the reverse sequence.

Problem

Upon power-up, indicators 
does not light up.

The indicator of heating 
does not light up, water is 
not heated.

Water does not flow from 
the hot water outlet valve.

Water leakage.

Water at the outlet from 
the heater is sometimes 
hot, sometimes cold.

The heating indicator 

«

Power

» 

continues 

glowing, while the water 
inlet valve is closed.

The indicators extinguish 
upon pushing the TEST 
button, the indicators do 
not light up upon pushing 
the RESET button.

Possible causes

1. There is no power supply.
2. The temperature limiter at 95°C is 
tripped or not activated.
3. The printed board is faulty.
4. Current leakage.

1. Water flow rate is less than 2.4 L/min.
2. The power mode switch is off.
3. The temperature limiter at 55°C is 
tripped due to overheating.
4. Too low water pressure in the water 
mains

1. Water feed is shut off.
2. The cold water inlet valve is not 
opened.

Problem with connection tightness of 
each pipe.

1. Unstable water pressure.
2. Water temperature at the outlet from 
the heater is too high causing repeated 
tripping of the overheating protection.

Failure of the water flow sensor.

Current leakage.

Elimination method

1. Make sure that power supply is 
switched on.
2. Activate the temperature limiter at 
95°C.
3-4. Contact a repair specialist in the 
Timberk service center.
1. Increase water flow rate.
2. Switch on the power mode switch.
3. Wait until the temperature limiter at 
55°C cools down and activates.
4. Wait until normal water pressure is 
restored in the system.

1. Wait until water feeding is restored in 
the water mains.
2. Open the cold water inlet valve.

Restore connection tightness.

1. Use the water heater only after 
stabilization of water pressure.
2. Decrease heating power, increase 
water flow rate.

Contact a repair specialist in the Timberk 
service center.

Contact a repair specialist in the Timberk 
service center.

ATTENTION!

WHN-4 OS, WHP-4 OS models with power of 3.5kW are designed 
for use in summer with water temperature at the inlet of the water 
heater not less than +16-18°C.