Saunier Duval Bithermal Heat Exchanger Isofast C28 E1 Ref. 57189
When you turn on the hot water tap in your home, the Saunier Duval Bitérmico Isofast C28 E1 heat exchanger is responsible for transferring heat from the primary circuit to the domestic hot water instantly. If this component fails, you will notice that the water comes out lukewarm or with fluctuating temperature, and the flow of domestic hot water decreases. This heat exchanger is compatible with several boilers from the ISOFAST range, such as models C 24 E, C 28 E, C 28 E1, F 28 E, and F 28 E1, among others. A technician must confirm through diagnosis whether it needs to be replaced when these symptoms occur to ensure an adequate supply of hot water.
- Type of part
- Bithermic heat exchanger
- Status
- Refurbished
- Catalogue reference
- 57189
- Warranty
- 1 year
Saunier Duval boilers compatible with reference 57189
Bitermal heat exchanger with reference 57189. Five confirmed compatibilities: C 24 E and C 28 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval C 24 E | ISOFAST | Contrasted |
| Saunier Duval C 28 E | ISOFAST | Contrasted |
| Saunier Duval C 28 E1 | ISOFAST | Contrasted |
| Saunier Duval F 28 E | ISOFAST | Contrasted |
| Saunier Duval F 28 E1 | ISOFAST | Contrasted |
Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.
How to check if ref. 57189 is the part for your boiler
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 57189. If it is not visible, do not identify the part from its shape alone.
- Check the full boiler model on its data plate and look for it in the model associations on this page.
- Compare the connections and physical body with the original part before installation.
- If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Symptoms that require diagnosis in the double heat exchanger 57189
The bivalent heat exchanger transfers heat to heating and domestic hot water. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
Domestic hot water comes out intermittently or with decreasing pressure.
Cause: Limescale builds up inside the heat exchanger and gradually restricts the water flow.
Check the cold water inlet filter and the filling valve; if they are clean and there is still a lack of flow, it is the heat exchanger.
- 02
There is neither heating nor domestic hot water, or only one of the two services is working.
Cause: The bivalent heat exchanger distributes heat between both circuits; if it becomes blocked or damaged, it affects both services unevenly.
Check that the 3-way valve and the pump are working before assuming the problem is with the heat exchanger.
- 03
Water is appearing under the boiler, in the area where the bithermal body is mounted.
Cause: Over time, the body is perforated by corrosion or by the scale accumulated inside.
Dry the area, pressurize the boiler, and check if the leak is coming from a fitting (which can be tightened) or from the metal body (in which case the part needs to be replaced).
- 04
When opening a hot water tap, the pressure of the heating system drops on the pressure gauge.
Cause: It is a sign that the bithermal heat exchanger has cracked internally and is mixing the primary circuit with the domestic water circuit.
Open a domestic hot water tap and observe the heating pressure gauge; if the needle drops significantly, it is a strong indication of internal mixing.
These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.
Technical sheet: heat exchanger Saunier Duval 57189
- Catalogue reference
- 57189
- Uniclima internal SKU
- IBCIC28E1
- Brand
- Saunier Duval
- Type of part
- Bithermic heat exchanger
- Units in stock
- 7 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval F 28 E Manual (PDF)Document © Saunier Duval, provided as a technical reference.
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