Saunier Duval Air Pressure Switch Isofast F30 E / Themafast F30 E - 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 boiler tries to ignite but quickly shuts off or the burner does not start.

  Cause: The pressure switch does not close the air contact, which causes the control board to cut off the gas for safety, even though the fan is working.

  Check that the extractor is rotating correctly and at a good speed. Ensure that the silicone tubes of the pressure switch are not disconnected, crushed, or contain condensate water.

• 02

  The display shows a fault or blockage related to air or flue gas evacuation, and it needs to be reset to attempt to ignite again.

  Cause: The PCB indicates that the pressure switch does not confirm the minimum depression required to allow ignition.

  Check the flue duct for any obstructions, such as birds, ice, or a blocked condensate trap that may reduce the draft, before replacing the part.

• 03

  The extractor works normally, but the boiler gets locked and does not allow the gas to pass.

  Cause: The pressure switch validates the pressure generated by the fan; if it does not switch, the control board interprets that there is no safe exhaust and does not open the gas valve.

  With the boiler off, gently blow through one of the silicone tubes and listen for the pressure switch to click; if it doesn't switch, the fault may be in the tube or the connection, not in the part.

• 04

  The fault is intermittent: sometimes it starts up properly and other times it locks up for no apparent reason.

  Cause: A loose diaphragm or a loose connection can cause the pressure switch to toggle right at the limit and fail only with wind or back pressure.

  Check that the electrical connectors (Faston) are properly fitted and free of rust, and that the pipes are not bent at any point along the route.

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

PCTF30HMOD

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.

Label code

605.99534

Set (opening/closing)

59/51 Pa

Contact electric charge

1(0.5)A / 250V~

Internal code

116189

Batch code

SFSEFF

Manufacturing date (week/year)

45/05