Combi boiler spare parts: circulation pump, 3-way valve, plate heat exchanger, expansion vessel, gas valve, NTC sensor and safety relief valve. Yedepa stocks original and compatible boiler parts for Vaillant, ECA, Demirdöküm, Baymak and Bosch combi boilers; the compatible boiler models are listed on every product page.
Combi Boiler Spare Parts by Part Group
- Circulation pump: Boiler-type pumps, primarily Wilo and Grundfos, are listed by power (W) and connection size in the circulation pumps group.
- 3-way valve: If only the motor is to be replaced, see 3-way valve motors; if it is to be replaced together with its body, see 3-way valve assemblies; cartridge, seal and shaft sets are under repair kits.
- Plate heat exchanger: Plate heat exchangers selected by the number of plates and screw spacing; scaling of the heat exchanger on the hot water side is the most common reason for replacement.
- Expansion vessel: Boiler expansion vessels by litre capacity and connection size (3/8", 1/2").
- Gas valve: Honeywell and boiler-brand-specific gas valves.
- NTC sensor: Immersion and clip-on (surface) type NTC sensors.
- Ignition and ionisation electrodes: Single, double and ionisation-type ignition electrodes (spark plugs).
- Flue fan: Fime-motor and brand-compatible boiler flue fans.
- Turbine and pressure sensor: Turbines (flow sensors) that read the hot water flow, and water pressure sensors and switches are in this group; the air pressure switches (air pressostat, pressure switch) that monitor the flue draught are listed separately.
- Safety and filling: 3 bar safety relief valves, filling loop taps and pressure gauges.
- Consumables and condensate: gaskets, O-rings and diaphragms, and the siphon and drain parts of condensing boilers under condensate system parts.
Compatible Boiler Parts by Brand
- Vaillant: Gas valves, heat exchangers, pumps and sensors for the Ecotec, Turbotec and Atmotec series; for example the Vaillant Ecotec Pro 24/25/28 and Turbotec gas valve.
- ECA: The ECA 3-way valve repair kit for the Proteus, Confeo and Calora series, and the 3-way valve stepper motor used in ECA, Demirdöküm, Vaillant, Viessmann, Ferroli and Ariston boilers.
- Demirdöküm: The Zilmet 7 litre expansion vessel (3/8" connection) and the Aden immersion NTC sensor for the Neva, Atron and Aden series.
- Ariston, Bosch, Buderus and Ferroli: The 8 litre 3/8" expansion vessel and the Bosch, Buderus and Viessmann 14-plate heat exchanger.
- Baymak: The ignition electrode (compatible with ECA Premix Proteus, Baymak Novadens Extra, Ariston) and the 220 V 70 N 3-way valve stepper motor for the Novadens and Eco series.
- Viessmann: The Vitopend 100 12-plate heat exchanger for the Vitopend series.
Values to Check When Choosing the Right Part
- Boiler model and series: Parts differ between series within the same brand; compare the full model name on the rating plate with the compatible model list on the product page.
- Connection size: The 3/8" versus 1/2" distinction for expansion vessels, filling loop taps and safety relief valves; the number of plates and screw spacing (mm) for heat exchangers.
- Electrical ratings: Voltage (V) and power (W) for pumps and flue fans; torque (N) and connector type for 3-way valve motors; resistance value and mounting type for NTC sensors.
- Capacity: Litre capacity and pre-charge pressure for expansion vessels; the number of plates corresponding to the kW output for heat exchangers.
Fault Symptoms and Replacement Guides
If the boiler heats but gives no hot water, the 3-way valve; if the pressure keeps dropping, the expansion vessel or safety relief valve; if there is noise and fluctuating heating, the circulation pump are the first parts to check. To distinguish the symptoms and for step-by-step replacement, you can read our 3-way valve, expansion vessel, safety relief valve and circulation pump guides. We keep the parts that technicians and technical service companies replace frequently during the winter season together in the catalogue, and make it easy to match the right part for bulk requirements using the compatibility information on the product pages.
-250x250.jpg "Vaillant Turbotec Combi Boiler Safety Valve Retaining Clip - Metal Circlip")
Brand: Generous
Model: 77890006029
Durable Metal Clip for a Reliable Connection
Compatible with Vaillant Turbotec combi boilers, this safety valve retaining clip is specially designed to provide a safe and secure connection. Its durable metal material ensures a long service life.
Key Features
Compatibilit..
$0.69
Ex Tax:$0.57
new
Brand: Huba Control AG
Model: HC020
The Huba Control 605.99E27 air pressure switch is the safety component that monitors the flue draft in room-sealed combi boilers. It does not close its contact until the fan is running and has created sufficient vacuum in the flue line; the PCB does not ignite the burner without this confirmation. T..
$8.54
Ex Tax:$7.12
-250x250.jpg "Vaillant Turbotech Combi Boiler 3-Way Valve Assembly")
Brand: I.T.M
Model: 5109
Features
Compatible Models: Vaillant Turbotech combi boiler series
Product Type: 3-Way Valve Assembly
Material: Brass
Function: Allows the combi boiler to switch between heating and hot water functions.
Durability: Resistant to corrosion thanks to t..
$62.91
Ex Tax:$52.43
Brand: I.T.M
Model: PHE152
Product Features
Number of Plates: 16
Compatibility and Use: Compatible with the Vaillant Turbotech series
Efficiency: Plates optimized for fast heat transfer
Maintenance: Requires regular maintenance and inspection.
Maintenance and Installation Information
During rep..
$23.10
Ex Tax:$19.25
Brand: Cewal
Model: AI0225
Product Features
Diameter: 40 mm
Function: Measures both temperature and pressure
Product Description
Designed to fit Vaillant VCK and Süsler combi boiler systems, this thermomanometer lets you easily read the pressure and temperature values of your system. The dual-function gauge pl..
$10.50
Ex Tax:$8.75
Brand: OEM
Model: 5140
Product Features
Compatible Models: Vaillant VCK series combi boilers
Material: Durable and long-lasting material
Design: Designed in a gooseneck shape, its clip-fit structure allows easy installation and removal
Product Description
Specially design..
$1.22
Ex Tax:$1.02
-250x250.jpg "Vaillant VCK Combi Boiler Membrane Diaphragm Gasket Kit (010365) | Membrane Disk Group")
Brand: I.T.M
Model: MEM05
Product Description
Vaillant VCK combi boilers use this specially made membrane diaphragm gasket kit, which balances water pressure changes and ensures that the boiler operates safely and efficiently. 010365 is the part code of this kit, which is also known as the membrane disk group and prevents l..
$3.58
Ex Tax:$2.98
Brand: Scopo
Model: AI0198
Designed for Vaillant VCK series combi boilers, this Potentiometer Control Knob lets you easily adjust your combi boiler's temperature and pressure settings. It is a spare part that offers convenience and durability.
Product Features
Easy Control: Lets you easily adjust temperature and pre..
$0.91
Ex Tax:$0.76
-250x250.jpg "Vaillant VUW Combi Boiler Filling Tap Head - White Plastic (Zamak)")
Brand: I.T.M
Model: FT52
The filling tap head compatible with Vaillant VUW, atmoMAX and turboMAX Pro / Plus combi boiler models is designed as a spare part used for filling the combi boiler with water. Made of white plastic, this filling tap head (also known as zamak) is a user-friendly solution with its durable constructio..
$0.99
Ex Tax:$0.83
Brand: Scopo
Model: AI0427
Designed specifically for Vaillant VUW combi boiler models, this combi boiler ring is an important spare part that supports efficient and safe operation of the boiler. By protecting various parts of the combi boiler, this ring extends the appliance's service life and improves its performance.
..
$2.74
Ex Tax:$2.28
Brand: Cewal
Model: AI0220
Product Features
Diameter: 40 mm
Function: ThermomanometerCountry of Manufacture: Italy
Product Description
Designed for use in Vaillant VUW combi boilers, this thermomanometer lets you check whether your system is operating efficiently and safely. You can r..
$10.94
Ex Tax:$9.12
Brand: OEM
Model: DRB01
This is the Type 1 size duraboard ceramic fiber insulation plate used in the combustion chamber of Viessmann boilers. Known in the field simply as the asbestos board, this part keeps the heat of the burner flame in the combustion zone and limits the heat transferred to the casing. Plates manufacture..
$8.91
Ex Tax:$7.42
-250x250.jpg "Viessmann Combi Boiler Ignition Transformer Zag2 07000088")
Brand: Anstoss
Model: 4933
Product Description
Specially designed for Viessmann brand combi boilers, this ignition transformer serves to ignite the gas of the appliance correctly and safely. The boiler needs the spark produced by this transformer to ignite the gas under correct operating conditions. If the ignition trans..
$10.93
Ex Tax:$9.10
-250x250.jpg "Viessmann Combi Boiler Three-Way Valve Motor (Straight Type, DC 24V)")
Brand: Generous
Model: 77890002050
Used in Viessmann combi boilers, the three-way valve motor is a critical actuator part that allows the appliance to switch between central heating and domestic hot water modes. Thanks to its straight-type step motor design, it positions the three-way valve precisely and in a controlled manner.
Wi..
$34.46
Ex Tax:$28.72
Brand: Grundfos
Model: 77890004013
The Viessmann combi boiler water flow sensor is an electronic sensor that detects that water is passing, and its flow rate, in the combi boiler's hot water circuit when a tap is opened. It is the Grundfos-manufactured VFS 1-20 E type (Grundfos part no 96577493). With the vortex principle, which has ..
$55.16
Ex Tax:$45.96
-250x250.jpg "Viessmann Vitodens 100 Combi Boiler Hydraulic Group By-Pass L Pipe Repair Part")
Brand: Generous
Model: 77890040102
Combi boiler hydraulic group by-pass L pipe is an important hydraulic connection part that helps maintain balanced circulation of system water inside the combi boiler. The by-pass line protects the pump and heat exchanger and balances system pressure.
This product is designed to fit the hydraulic..
$23.87
Ex Tax:$19.89
Brand: Önaysan
Model: 7181521517
Viessmann Vitopend 100 combi boiler expansion vessel: 6 liters, 3/8" male threaded union, round flat body (Ø335 × 85 mm). It is the vessel type used in Vitopend 100-W (WH1D, A1JA, A1JB, A1HB) and Vitopend 050-W models; it replaces original part numbers 7831308 / 7856838. It absorbs the water that ex..
$28.64
Ex Tax:$23.87
-250x250.jpg "VZ 2/10 HDC 400 Combi Boiler Ignition Transformer (Baymak - Baxi Compatible)")
Brand: Anstoss
Model: AR20
Ensuring that gas ignites safely in your combi boiler's combustion chamber, the VZ 2/10 HDC 400 Ignition Transformer (Coil) is fully compatible with Baymak and Baxi appliances. By producing the high-voltage spark the appliance needs at start-up, it allows the system to heat safely and without interr..
$13.26
Ex Tax:$11.05