Flow heaters / Booster heaters

These water heaters, mainly used for heating of water or oil, are mostly designed according to customer specification.

Backer produces a wide range of flow-through heaters for liquid heating, flexible according to customer specification. Different options, electrical connections and water couplings make it easy for you to find the perfect flow-through heater for your application. 



>> Example of applications

  • Solar systems
  • Pool heater
  • Heat pump
  • Floor heating
  • Dish washers


Flow heaters - technical info:



Tube and element in stainless steel AISI 304, 316L


Tub Ø 76 mm, 101.6 mm, 63.5 mm


Inlet G 3/4'', 1'', 1 1/4''
Outlet G 3/4'', 1'', 1 1/4''


Wide range of electrical connections and water couplings
Can also be supplied with thermal insulation
Can also be supplied with different types of connection boxes

Water preassure

Depending on model: max 5-7 bar water presure


The elements fulfil standards acc. to
EN 60335-1

Optional Thermostat, temperature sensor, thermal cut-off, flow sensor, cable harness, connection box, thermal insulation, air vent, drainage valve, etc


Product Example - Flow Through Heater

Flow through heaters can also be assembled with Backer standard products. A complete heater consists of a black enamelled steel tube, a screw-plug immersion heater and a terminal box with temperature control.

Flow Through Heater for dish washer



Genomströmmare för diskmaskin

Flow heater for dish washers or water pumps.
Temperature increase 1.5°C per minute between 40°C and 73°C. (higher rate of increase at lower water temperature).


Tubular heating element aluminium tube. Outer tube EN 1.4301 or EN 1.4408

Dimension Length 145 mm 
external Ø 32 mm, internal Ø 30,5 mm
Power Up to 1800 W
Voltage 120-203 VAC
Surface load Max 8.9 W/cm²
Fixing device Hose clamp, rubber sleeve Ø 32 mm
Flow Max. 45 l/minute
Operating temp.

Built-in: Cut-off thermostat temp 98°C
and fuse temp. 229°C

Safety The elements meet requirements acc. to EN 60335-1
Acc. to VDE krav
Meet UL requirements acc. to UL 1030


>> Benefits
  • Compact construction
  • Low surface temperature


>> Fields of application
  • Dish washers
  • Bubble Baths 


PDF: Product information - flow through heater for dish washer


Backer BFU - Flow Heater Unit - Supplementary heater

The supplementary heater is generally used as a complement to a heat pump but can also be used together with other heating appliances. The heater will operate when the heat pump capacity is not sufficient, for example during cold winter days. A supplementary heater also adds extra security if the heat pump malfunctions.


Material Heating element and tube: AISI 304/EN 1.4301
Casing material: Al. Zn.-plated steel
Water pressure Max 7 bar
Water quality Non corrosive and oxygen free
Operating temp. ~60°C
Safety IP44
Manufactured according to demands EN 60335-1,
EN 60335-2-40 and comply with WEEE/RoHS
Options Thermostat 30-90°C


Color RAL 9002



Technical specification:

Max power

5 kW 8 kW 9 kW 15 kW 26 kW 42 kW
Step 1 1.7 kW 2 kW 3 kW 5 kW 4 kW 4 kW
Step 2 3.4 kW 6 kW 6 kW 10 kW 7 kW 12 kW
Step 3 15 kW 24 kW
Voltage 230V/1~ 230V/1~ 400V/3~ 400V/3~ 400V/3~ 400V/3~
Connection G1'' G1'' G 1/4'' G 1 1/4'' G 1 1/4'' G 1 1/2''

(HxWxD) mm







Thermal Cut-off 96°C 96°C 96°C 96°C 110°C 110°C


 PDF:  Product data sheet: Backer Flow Heater Unit


Flow through heater for dishwasher


Flow heater for connection to the water pump in the dish washer. Temperature increase 2°C per minute between 40°C and 73°C (higher rate of increase at lower water temperature).

Material Tubular heating element AISI 316L/EN 1.4404
Outer tube AISI 316L/EN 1.4404 or AISI 304/EN 1.4301
Dimension Lenght 145 mm Ø 40 mm external, Ø 38,6 internal
Power Up to 2000 W
Voltage Up to 240V/1~
Suface load Max 15,3W/cm²
Assembly Hose clamp, rubber seal
Flow Water volume in machine 3.6 liter
55 liter/minute
Operating temp. Up to 90°C depending on thermostat
Safety Fulfills standards acc. to EN 60335-1


 PDF: Product data sheet: Flow Through Heater for dish washers


Flow through heater in aluminium

- for e.g. coffee machnines

Double tubular heating element with interjacent water pipe, for heating water in appliances with continous flow e.g. coffee machnies


Material Extruded aluminium with
pipe in aluminium or stainless steel
Dimension acc. to customer specification
Weight 358 g
Voltage 230 V
Power 2 x 650 W
Water pressure 1-2 Bar
Pre heating 25 seconds (to 130°C)
Temperature 70°C (continousely at 260 ml/min after pre-heating)
Flow 260 ml/min
Surface load 17.24 W/cm²
Safety The elements meet requirements acc. to EN 60335-1


>> Benefits
  • Possibility to generate steam
    (30g steam/minute)
  • Compact design, easy to place in small applications


 PDF:  Product data sheet flow through heater aluminium

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