Saunier Duval Themafast F25 E Air Pressure Switch Ref. 605.99534

Saunier Duval boilers compatible with reference S5744100

Pressure switch with reference S5744100. 21 verified compatibilities: F 30 E H-MOD and F 35 E1.

Proven compatibility

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. S5744100 is the part for your boiler

The part reference, model, and equipment revision must be verified against the manufacturer's documentation.

1. Find the reference printed on the installed part and check whether it matches the catalogue reference S5744100. If it is not visible, do not identify the part from its shape alone.
2. Check the full boiler model on its data plate and look for it in the model associations on this page.
3. Compare the connections and physical body with the original part before installation.
4. If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.

Symptoms that require diagnosis in the pressure switch S5744100

The pressure switch controls the air or water pressure to authorize operation. These are the typical symptoms and what to do:

Common symptoms and faults

• 01

  The extractor is spinning, but the burner does not ignite and the boiler locks out with a fault warning.

  Cause: The pressure switch does not close the contact that confirms that the extraction is correct and the gas does not activate.

  Check that the external flue terminal is not obstructed, especially if the outlet is horizontal and short.

• 02

  The boiler modulates strangely, abruptly increasing and decreasing power, and sometimes it locks itself.

  Cause: A limit pressure switch may oscillate near its switching point when the fan changes speed during modulation.

  Before replacing it, check that the modulating fan responds smoothly throughout its range, without jerks.

• 03

  The extractor starts and stops repeatedly before the boiler completely locks out.

  Cause: The retries of the control board are waiting for the signal from the pressure switch that is not arriving.

  Check that the silicone tubes are not pinched by other components in a tight assembly, typical of compact boilers.

• 04

  The fault is more frequent when it is very cold or there is a lot of condensation in the siphon.

  Cause: The condensate water can reach the pressure take-off tubes if the siphon does not drain properly, leading to an incorrect reading of the pressure switch.

  Check the siphon and the condensate drain before assuming that the pressure switch is faulty.

Fault codes Saunier Duval that require diagnosis

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.

Datasheet for Saunier Duval pressure switch S5744100

Catalogue reference

S5744100

Uniclima internal SKU

PCSTF25E

Brand

Saunier Duval

Type of part

Pressure switches

Units in stock

7 units

Status

Refurbished

Warranty

1 year

Shipping

Delivery time shown at checkout

Return

14 days

Part data and available documentation

Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.

Component code

605.99534

Switching pressure (setpoint)

59/51 Pa

Electrical classification

1(0.5)/250~

Internal code

116189

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.