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.
Brand: Önaysan
Model: 7181521519
Manufactured by the Önaysan brand, this expansion vessel is specially designed for Bosch and Buderus Logamax Gb162 combi boiler models. With its 7-liter capacity, it is ideal for homes and small businesses. This vessel is used to balance the expansion and contraction of hot water in combi boiler and..
$37.71
Ex Tax:$31.42
-250x250.jpg "14-Plate Flat Type Combi Boiler Plate Heat Exchanger Compatible with Demirdöküm Baxi Ariston (166mm Screw Spacing)")
Brand: I.T.M
Model: PHE156
Specially manufactured for technical services looking for fast response and ideal capacity in heating domestic hot water (DHW) in combi boiler systems, the 14-Plate Flat Type Heat Exchanger offers a definitive solution to hot water fluctuation complaints. Its standard 14-plate volume delivers optimu..
$19.13
Ex Tax:$15.94
Brand: Önaysan
Model: 7181521514
Manufactured in Turkey by Önaysan, the Baymak Baxi Combi Boiler Expansion Vessel offers high efficiency in small and medium-sized homes with its 14/1 connection size and 6-liter capacity. It fits Baymak Baxi and similar combi boiler systems perfectly.
Product Features
Model: Baym..
$28.49
Ex Tax:$23.74
-250x250.jpg "14/1 6L Combi Boiler Expansion Vessel (Winkelmann)")
Brand: Winkelmann
Model: WIN05
The Winkelmann combi boiler expansion vessel, with its 14/1" connection diameter and 6-liter capacity, is an ideal spare part for Baymak combi boiler systems. Made in Germany, this high-quality product ensures that your combi boiler systems operate efficiently and safely.
Product Features
..
$39.34
Ex Tax:$32.78
-250x250.jpg "18-Plate Flat Type Combi Boiler Plate Heat Exchanger - Compatible with Demirdöküm Baxi Ariston (166mm Pin Spacing)")
Brand: I.T.M
Model: PHE158
The 18-Plate Flat Type Combi Boiler Heat Exchanger, which ensures uninterrupted, fast and high-efficiency heating of domestic hot water (DHW) in combi boiler installations, is a professional solution developed against chronic hot water fluctuation and scaling problems. Specially supplied for field s..
$22.77
Ex Tax:$18.98
-250x250.jpg "3 Bar Combi Boiler Safety Relief Valve - Baymak, Baxi, Potterton Compatible")
Brand: Novasfer
Model: 77890026017
The 3 Bar Combi Boiler Safety Relief Valve is a high-quality safety component used in Baymak, Baxi and Potterton combi boiler systems to balance water pressure and provide protection against overpressure. Its O-ring push-fit, long-type design allows easy installation.
Product Features
Pres..
$6.45
Ex Tax:$5.37
Brand: Bitron
Model: AI0355
Product Description
The Bitron 3-way valve right hydraulic group is an important component that directs the hot water and heating circuits in combi boiler systems. Defined as a left block, this product is designed to be fully compatible in particular with Baymak, Baxi, Lambert, DolceVita, Falke, Ec..
$27.07
Ex Tax:$22.56
Brand: Scopo
Model: AI0162
Product Description
The 3/8 - 1/2 Converter Combi Boiler Fitting is an adapter that allows transition between two pipes or hoses of different sizes. It is used especially in combi boiler connections when the installation does not match old or new standards. This adapter is generally made of cop..
$1.32
Ex Tax:$1.10
Brand: Scopo
Model: AI0163
Product Description
The 3/8 - 3/8 Combi Boiler Adapter Fitting is an adapter used to connect two pipes or hoses of the same size. This type of fitting is usually preferred when an additional piece or extension is needed in the installation. It is used especially in combi boiler connections to a..
$1.42
Ex Tax:$1.18
Brand: Önaysan
Model: 7181521503
3/8" 6L Combi Boiler Expansion Vessel
Product Features:
Model: Combi Boiler Expansion Vessel
Capacity: 6 L
Connection Size: 3/8"
Product Diameter: 391mm
Depth: 67mm
Max. Operating Pressure: 3 Bar
Operating Temperature: -10 / 90 °C
Country of Manufacture: Turkey
Brand: Önaysa..
$28.33
Ex Tax:$23.61
Brand: Önaysan
Model: 7181521507
The Önaysan-brand 7-liter Rectangular Combi Boiler Expansion Vessel is compatible with combi boiler brands such as Neva, Atron, Nepto and Lynx. It is used in heating systems to compensate for the volume expansion caused by temperature changes.
Product Features
Model: Rectangular Combi Boile..
$29.79
Ex Tax:$24.82
Brand: Önaysan
Model: ONA08
Manufactured by Önaysan, the Ferroli Combi Boiler Expansion Vessel with Hook is specially designed to ensure the effective and safe operation of heating and cooling systems.
Product Features
Model: Ferroli Combi Boiler Expansion Vessel with Hook
Capacity: 8 L
Connection Size: 3/8"
Hei..
$40.98
Ex Tax:$34.15
-250x250.jpg "4-Lug Combi Boiler Plate Heat Exchanger 12 Plates – Compatible with Viessmann Vitopend 100 WHE / WHO (ITM 7817471)")
Brand: I.T.M
Model: PHE169
Product Description
The 4-lug 12-plate combi boiler heat exchanger is a high-efficiency heat transfer element compatible with Viessmann Vitopend 100 WHE / WHO models.
By heating domestic hot water quickly and evenly, it improves the performance of the appliance.
Manufactured by ITM, this mode..
$33.15
Ex Tax:$27.62
-250x250.jpg "6 Liter Combi Boiler Expansion Vessel (CIMM – M14 Connection – Baymak, Baxi, Chappee, Lambert, Falke, Westen, Roca Compatible) | JJJ005693920 – 125995198")
Brand: CIMM
Model: CMM01
Product Description
The CIMM branded 6 liter expansion vessel is a high-quality expansion vessel that works with Baymak, Baxi, Chappee, Lambert, Falke, Westen and Roca combi boiler models. It balances the expansion of water in the combi boiler system as it heats up, helping the installation operate..
$38.07
Ex Tax:$31.73
Brand: Bitron
Model: AI0651
Product Features
Product Name: 7 bar combi boiler safety relief valve
Brand: Bitron
Compatible Brands: Ariston, Chaffoteaux
Pressure Rating: 7 bar
Product Code: 33340015
Reference No: 256/17-2
Product Model Number: 60000171-02
..
$4.74
Ex Tax:$3.95
-250x250.jpg "8 Liter Rectangular Combi Boiler Expansion Vessel (Zilmet – with Hook – 3/8\" Connection – Ferroli Compatible 39804890)")
Brand: Zilmet
Model: ZLM13
Product Description
Made by Zilmet, the 8 liter rectangular combi boiler expansion vessel is designed to be compatible with Ferroli combi boilers. With code 39804890, this model balances water expansion in heating systems, ensuring safe and efficient operation of the combi boiler. Its hook (brack..
$35.95
Ex Tax:$29.96
Brand: Sigma
Model: AI0489
This 845 Sigma gas valve is a component used to control gas flow in combi boiler systems. Manufactured in Padua, Italy, this valve is designed in accordance with high quality standards. Generally used in natural gas or LPG systems, this valve is set up to ensure smooth and safe gas flow within speci..
$68.21
Ex Tax:$56.84
Brand: Sigma
Model: AI0516
This model is a gas valve used in combi boilers and heating systems and is manufactured by the 845 Sigma brand in Padua, Italy. The gas valve is a vital component for correctly controlling the gas flow in the combi boiler system. This model is designed for use with both natural gas and LPG.
Pro..
$68.21
Ex Tax:$56.84