Wilo ZRS18/4-1 Ku Circulating Pump - Saunier Duval Isomax / Isotwin - Ref. 4517752/4616124
Wilo circulating pump, model ZRS18/4-1 Ku, identified by its label with article codes 4517752 and 4616124. It is installed in Saunier Duval boilers from the Isomax and Isotwin ranges and circulates water in the heating or domestic hot water circuit. It is replaced when the boiler stops heating due to circulation failure or the pump does not start.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 05738300
Circulating pump with reference 05738300. Six confirmed compatibilities: Isomax C 28 E and Isomax F 28 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Isomax C 28 E | Isomax | Contrasted |
| Saunier Duval Isomax F 28 E | Isomax | Contrasted |
| Saunier Duval Isomax C 28 E2 | Isomax | Contrasted |
| Saunier Duval Isotwin C 24 E | Isotwin | Contrasted |
| Saunier Duval Isotwin F 24 E | Isotwin | Contrasted |
| Saunier Duval Isotwin F 28 E2 | 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 ref. 05738300 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 05738300. 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 circulator pump 05738300 resolves.
The circulation pump circulates the water in the heating circuit. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler is on, but the radiators are cold or just lukewarm.
Cause: The pump is not moving the water, so the heat is not reaching the circuit.
Touch the pipe right at the outlet of the pump: if you don't notice a temperature difference compared to the inlet with the boiler calling for heat, the pump may be failing.
- 02
The pump does not start, it doesn't even make a noise when the heating is turned on.
Cause: The rotor may be blocked or not receiving power.
Check if there is power at the pump connector before assuming that the motor is broken.
- 03
You can hear the pump running, but it makes a strange noise, like a rubbing or rattling sound.
Cause: There may be air in the rotor or dirt accumulated in the pump.
Bleed the highest point of the circuit and wait a few minutes with the pump running to see if the noise decreases.
- 04
After turning off the heating for several months, now it doesn't heat at all when turning it back on.
Cause: The rotor may have seized up due to not being used for a long time.
Try to manually unlock the rotor using the front screw before replacing the pump.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 11 | Pump blocked. | If the sanitary pump 05738300 seizes or fails electrically during the DHW recharge, the electronics detect circulator blockage and trigger "11". Verification: force DHW demand, check 230 V and current in the pump, and release/inspect the shaft from the front cap. |
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 05738300 circulation pump.
- Catalogue reference
- 05738300
- Brand
- Saunier Duval
- Type of part
- Pumps
- Units in stock
- 5 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- Manufacturer
- Wilo
- Model / code
- ZRS18/4-1 Ku
- Item codes
- 4517752 / 4616124
- Pressure / protection rating
- PN6 - IP44
- Insulation class
- Class F - TF95
- Speed
- 2100 min-1
- Current
- 0.31 A
- Power
- 71 W
Frequently asked questions about the circulator pump 05738300
Is the Wilo ZRS18/4-1 Ku pump suitable for the Saunier Duval Isotwin F24E?
What is the power of the Wilo ZRS18/4-1 Ku pump in the Isomax C28E?
Does the Wilo ZRS18/4-1 Ku pump circulate heating water or domestic hot water in the Isotwin C24E?
What Wilo article codes are on the pump label of the Isomax Condens F35E?
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