Saunier Duval Hydraulic Block Pump Semia Tek F 24 Ref. 0020037988
In the Saunier Duval Semia Tek range boilers, the Hydraulic Block Pump Semia Tek F 24 Ref. 0020037988 is a component that conducts and distributes water between the circuits. If this part fails, you may notice leaks, loss of pressure, or issues with domestic hot water production, which can lead to faults such as F.75, F.23, F.24, or F.20. It is installed in models like Isofast Condens F 35 E, Themafast Condens F 24E, among others. It is advisable to replace it upon detecting these symptoms or in case of evident fault.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 0020037988
Hydraulic group with reference 0020037988. 12 verified compatibilities: Isofast Condens F 35 E and Isofast Condens F 30 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Isofast Condens F 35 E | Isofast Condens | Contrasted |
| Saunier Duval Isofast Condens F 30 E | Isofast Condens | Contrasted |
| Saunier Duval Isofast 21 Condens F 35-B | Isofast Condens | Contrasted |
| Saunier Duval Isofast 21 Condens F 25 | Isofast Condens | Contrasted |
| Saunier Duval Isofast F 30 E H-MOD | Isofast (non-condensing) | Contrasted |
| Saunier Duval Isofast F 35 EA | Isofast (non-condensing) | Contrasted |
| Saunier Duval Isofast F35E H-MOD | Isofast (non-condensing) | Contrasted |
| Saunier Duval Themafast Condens F 24E | Themafast Condens | Contrasted |
| Saunier Duval Themafast Condens F 30E | Themafast Condens | Contrasted |
| Saunier Duval Themafast Condens F 30 H-MOD | Themafast Condens | Contrasted |
| Saunier Duval Themafast F 30 E H-MOD | Themafast | Contrasted |
| Saunier Duval Themafast F 25 E H-MOD | Themafast | 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. 0020037988 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 0020037988. 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 0020037988 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 heating system is partially working: some radiators heat up while others remain cold.
Cause: The hydraulic block does not distribute the water flow properly throughout the system.
Check if the issue is related to bleeding or imbalance in the system before inspecting the block.
- 02
The integrated pump makes noise or vibrates noticeably when the boiler is on.
Cause: The pump shaft may be worn or have trapped air in the circuit.
Bleed the heating circuit properly and repeat the test before replacing the part.
- 03
You notice that the domestic hot water and heating do not work as well at the same time.
Cause: The hydraulic block manages both circuits; a fault can affect only one of them.
Note whether the problem occurs always or only when you request domestic hot water and heating at the same time, before deciding on the replacement.
- 04
There is dripping or water leakage under the boiler, in the area of the block.
Cause: Internal seals can lose tightness over time and with temperature changes.
Dry the area and check after a complete cycle to confirm that the leak is coming from the block and not from a nearby fitting.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.75 | The control does not detect an increase in pressure when the pump starts (lack of water/pressure or pump/sensor fault). | If the circulator (block 0020037988) is blocked, does not start, or does not respond, the pressure sensor does not detect the expected increase and the boiler locks out with F.75; check electrical/PWM start-up, consumption, and that the rotor spins after bleeding. |
| F.23 | Safety shutdown due to excessive temperature difference between flow and return. | A blocked pump or one working at minimum power prevents circulation, increases the ΔT, and triggers F.23; check that the circulator is rotating, its consumption and flow rate, and bleed the primary. |
| F.24 | Safety shutdown due to excessively rapid temperature rise. | If the circulator of block 0020037988 is seized or has insufficient power, the water does not dissipate heat and the temperature rises quickly; check the pump's rotation/consumption, PWM signal, and bleed the circuit. |
| F.20 | Safety shutdown of the temperature limiter (overheating). | The lack of circulation due to a blocked pump in block 0020037988 causes overheating in the heat exchanger; check the start and flow of the circulator, free the shaft if it is seized, and bleed. |
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.
Data sheet for the Saunier Duval hydraulic group 0020037988
- Catalogue reference
- 0020037988
- Brand
- Saunier Duval
- Type of part
- Hydraulic units
- Units in stock
- 7 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Frequently asked questions about the hydraulic group 0020037988
Is this hydraulic block compatible with my Semia F 24 boiler?
Which boiler models are compatible with this hydraulic block?
Does this hydraulic block work for a Themafast Condens F 24?
What are the fault codes that may indicate a problem with this hydraulic block?
Can I use this hydraulic block in a Isofast F 30 E H-MOD boiler?
Spare parts related to Saunier Duval Isofast Condens
