Hydraulic part Isofast, Isotwin and Isomax Ref. 0020048257
In the Isofast, Isotwin, and Isomax boilers, the hydraulic component is essential for the conduction and distribution of water between the circuits. If it has faults, you may notice leaks, pressure loss, or issues with the production of domestic hot water. This component is compatible with several models, such as the 21 CONDENS F 25 from the Isofast range and the CONDENS F 30 B and F 35 B from Isomax, as well as others from the Isotwin series. It is recommended to replace it when you observe these symptoms to maintain the operation of your boiler.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 0020048257
Hydraulic group with reference 0020048257. Nine confirmed compatibilities: 21 CONDENS F 25 and CONDENS F 30 B.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval 21 CONDENS F 25 | ISOFAST | Contrasted |
| Saunier Duval CONDENS F 30 B | ISOMAX | Contrasted |
| Saunier Duval CONDENS F 35 B | ISOMAX | Contrasted |
| Saunier Duval C 25 E | ISOTWIN | Contrasted |
| Saunier Duval C 30 E | ISOTWIN | Contrasted |
| Saunier Duval CONDENS F 25-A | ISOTWIN | Contrasted |
| Saunier Duval F 25 E H-MOD | ISOTWIN | Contrasted |
| Saunier Duval F 30 E H-MOD | ISOTWIN | Contrasted |
| Saunier Duval V 25 | ISOTWIN | 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 the reference 0020048257 is the part for your boiler.
What determines it is not the boiler model, but the reference printed on the part you already have installed.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 0020048257. 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 and faults that the hydraulic group 0020048257 resolves.
The hydraulic group includes the valve, the by-pass, and the water connections. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The hot water takes time to come out or arrives at an irregular temperature.
Cause: This part is part of the water flow to the faucet; an obstruction or internal leak alters the flow rate that reaches the heat exchanger.
First, check the pressure of the installation and the water inlet filter before suspecting this part.
- 02
Water appears under the boiler even though there is no clear point of leakage.
Cause: An internal crack in this part can leak water without being noticeable from the outside until it accumulates.
Dry the entire lower area of the boiler and turn it on to see if the dripping reappears exactly at this point in the circuit.
- 03
The pressure in the circuit gradually decreases and needs to be topped up frequently.
Cause: This type of hydraulic part houses seals that, when degraded, allow water to leak slowly and steadily.
Rule out leaks in radiators and the safety valve before considering this part as the source.
- 04
There are noises of flow or small knocks when starting the heating or the domestic hot water.
Cause: A reduced internal passage due to scale or a deformed part changes the water velocity and generates noise.
Bleed the radiators properly and check the system pressure before attributing the noise to this part.
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.
Hydraulic group sheet Saunier Duval 0020048257
- Catalogue reference
- 0020048257
- Brand
- Saunier Duval
- Type of part
- Hydraulic units
- Units in stock
- 1 unit
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- 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 25 E H-MOD Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the hydraulic group 0020048257
Does this part fit the Isofast 21 Condens F 25?
Does this part also work for the Isotwin F 30 E H-MOD?
Spare parts related to Saunier Duval ISOTWIN
