
REZI electric instantaneous water heater has being manufactured since 1988.
Many years of experience has resulted in designing a device which performance capabilities have been
appreciated by many end-users.
Designing, production and service of water heaters are in compliance with Quality Providing System
in accordance with ISO 9001:1994 norm requirements - Certificate no 79523 issued by Bureau Veritas
Quality International.
The Rezi Water Heater is also approved by Energy Safe Victoria, Approval Number VO5452.
The heater has Quality Qualification Certificate - permit granted by the Polish Centre for
Testing and Certification in Warsaw to be marked with the B safety sign and E effectiveness sign as well
as a German safety certificate TUV.
REZI heater has also protection issued by Patent Office.
The heater posse’s protection before burning.
The compact size of the REZI heater makes it possible to install next to bathroom basin, kitchen sinks or shower cabins.
One water heater can supply one or more hot water supply terminals.
The heater is especially useful in buildings with no gas supply system.
Water flows along the hot heating coil made of resistant wire.
REZI water heater supplies hot water as soon as the hot water tap is turned on, instead of waiting for running
water to get hot as in traditional systems.
The Heater comes with heating units of different electric power: 3.3 kW, 4kW, 5kW, 7.5kW, 9kW and 11kW.
Electric energy is used only when hot water is turned on from the tap which makes its consumption lower than typical
gas hot water systems.
The heating element power is a factor that decides of the amount and temperature of water leaving the heater.
Water temperature can be lowered or raised by adjusting water flow.
The REZI water heater incorporates a basic design of a heating element which is placed on a water unit/heating
unit is made of basis with cold and hot water stub pipes.
Inside the heating unit there is a heating element with water canals with heating coli inside and elements designed
for energy supplying.
Everything is enclosed in a sleek housing.
Heater is equipped with:
-Pressure-less installation set: heating unit, battery, tap, strainer, installation spanner,
additional tap strainer, service manual, authorized service centre lists, and warranty.
- pressure arrangement set: heating unit, cut-off valve with filter, connector, installation spanner,
additional tap strainer, service manual, authorized server centre list and warranty.
Additional Attachments Available:
shower handle
switch
shower holder
shower hose
elbow with reduction
cut-off valve with filtering strainer
Rezi "Tornado" (Top Selling Attachment)
4. 4. Principals of heater maintenance.
The REZI water heater should be installed in a correctly and used according to its properties is completely safe during
operation.
Before installation and activation of the heater, strictly obey following advice:
- The heater cant be installed in buildings where the temperature falls below OºC
- Don’t leave damaged or disassembled heater connected to the electric energy source.
- Heater connection to energy source should be done by qualified electrician.
- Use electrical wire of there proper face area with relation to the heater power.
- Before putting the plug into socket check whether the heater is vented.
- Using heater which is damaged or out of order is forbidden.
Using the heater contrary to the regulation will result in the manufacturer revoking any
responsibility for damages which are results of self willed alternations and/or heater repairs.
5. 5. Requirements for electric and water supply system connection.
Connection to a water supply system.
The REZI heater belongs to the low-pressure appliance class.
It can work in water pipe networks where the pressure is not lower than 0,02 Mpa or higher than 0,6 Mpa which is
caused by use of automatic drain valves installed near to a heater (in this case a pressure redactor should be installed)
The device should have a stable connection to the electric installation with the earth clamp.
Connection to wiring.
Connections must be done by a professional electrician.
The heater can be connected to the wiring in the TN-S or TN-C-S system with copper wires and section adequate to
the heaters rated current.
Every fall of voltage below 230V decreases heating efficiency by 2% and decreases the temperature of the water heater.
6. 6. Principle of functioning.
Turning on the warm water hand wheel causes that the cold water is supplied to the heating coil and than direct to the
tap or shower. The temperature depends on the pressure and temperature of water which flows into the heater.
Turning off the hot water tap causes interruption with the power supply to the heating coil.
Water temperature can be lowered or raised by adjusting water flow.


The heater can be assembled in pressure less arrangement - with the valve ahead of the heater and also in a
pressure arrangement - with the valve behind the heater.
7.1 Pressure less arrangement assemble
A) Use the attached spanner only to assemble the heater.
Before starting the installation clean carefully all threads.
Seal the G 1” thread of the battery body with attached nut using Teflon tape (Picture 2), and then screw it into the pipe
fitting in the wall
B) Make sure that the two stub pipes are assembled upward.
Screw in the battery carefully. Do not strip the thread.
Do not hold the battery using the two hand wheels.
Hold the battery as shown on Picture 3.

C) The distance between the pipe fitting and the forehand of the G”1 nut should be 1-4mm.
After establishing the positions of the battery carefully tighten up the nut. (Picture 4)
D) Before assembling the tap make sure that both hand wheels are turned off.
Screw on the blank nut onto the right stub pipe (M18x2), open the cold water supply valve to let the
water flow and remove any impurities from the battery body. (Picture 5)

E) Place the strainer in the left stub pipe. (Picture 6)
F) On the stub pipes assembly the heater and on the lower end assembly the tap or shower set. (Picture 7)

G) Assembly the heater on the battery with extraordinary care. Both nuts should be tightened uniformly. (Picture 8)

I) Turn on energy supply. (Picture 10)

J) Using the three way battery it is possible to assemble the heater in a pressure less arrangement. (Picture 14)


It is also possible to install the heater on the existing battery. In place of the existing tap you can install:
a) An elbow join to which the battery is assembled (inside threads M22”x1,5 and G 1”)
b) Reducer (shower connector - inside thread M22x1,5) to which you can assembly the elbow
(outside thread G1/2”) and finally battery.
Continue onto the next step, as in the case pictured above.
If during operational use the air flows out of the heater instead of the water shut off the water supply
immediately and turn off the power supply.
Vent the heater before reuse.
The heaters assembled in pressure less arrangement are sold with diffuser, which is used for water diffusion.
Impurity inside a diffuser can cause:
-water outflow decrease or decay
-over-heating or such a water outflow decrease, that makes the heater impossible to switch on.
Cleaning the diffuser is very simple - release and clean the diffusing rings (Picture 16)

It is recommended to replace the diffuser strainer when is used.
To make the heater operate longer there is a strainer in the right stub pipe (Picture 6).
Clean the strainer or replace it with the new one when the water temperature unexpectedly rises or there is no water outflow.
To avoid the impurity it is recommended to install REZI water filter ahead of the heater.
Ask your sales representative to give you information about REZI water filters.
9. 9. Guaranty
The manufacturer gives 24 month guaranty from the date of purchase but not longer than 36 months from the
production date.
Any defects appearing during guaranty period will be fixed for free within 14 days from the defect declaration.
The heater should be delivered to the producer or authorized service centre with the guarantee certificate.
No certificate available or leaden seal damage means the guarantee loss.
Following the service manual steps assures correct operating of the heater.
According to International safety Norm the device should be tested every 30 months.
Q. The water from the heater is too cold.
A. Check AC voltage and eliminate voltage drops
Q. The water from the heater is too hot
A. Clean the diffuser or replace the diffuser strainer.
A. Check the cleanness of the water supply pipes.
Q. The heater does not operate.
A. Check the power supply and replace the safety devices.
A. Check if the water supply pressure is not too low
Q. The heater operates with interruptions
A. Check the water supply pressure
A. The heater should be examined by authorized service centre.
Thank you for purchasing REZI heater.
We wish you a lot of satisfaction while using REZI heater.