Vaillant Air Pressure Switch VMW ES 24/282/4-5 Ref. 0020041905

Vaillant boilers compatible with reference 0020041905

Pressure switch with reference 0020041905. 17 confirmed compatibilities: VMW 24/282/4-5 RV and VMW 24/282/4-5 RV R2.

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. 0020041905 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.

1. Find the reference printed on the installed part and check whether it matches the catalogue reference 0020041905. 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 and faults that the pressure switch 0020041905 resolves.

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 starts the fan pre-purge but locks out before igniting the burner.

  Cause: The pressure switch does not close the contact that detects the pressure difference generated by the fan during the pre-purge.

  Make sure that the fan spins freely and at a good speed; if it spins slowly, the pressure switch will not receive enough pressure to switch.

• 02

  The ignition fault is intermittent: sometimes the boiler starts up properly and other times it stops just after the pre-purge.

  Cause: A limit switch on the pressure switch causes small variations in draft to determine whether the boiler ignites or locks out.

  Check the silicone tubes of the pressure switch to see if they are partially blocked or poorly connected at either end.

• 03

  After cleaning or handling the flue duct, the boiler started to show an air pressure fault.

  Cause: A small misalignment in the duct can change the back pressure just enough for the pressure switch to stop switching within its range.

  Check again that the flue duct is properly assembled and sealed after handling, before replacing the part.

• 04

  The fault only appears when cold, right after starting the boiler in the morning, and the rest of the day it works without any issues.

  Cause: The condensation accumulated overnight in the pressure intake pipe can clog it just enough to prevent the first switch of the day.

  Cut off the power for a moment and disconnect the silicone tube from the pressure switch; check that no accumulated water is dripping before declaring the part faulty.

Fault codes from Vaillant that this part resolves.

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.

Vaillant 0020041905 pressure switch datasheet

Catalogue reference

0020041905

Brand

Vaillant

Type of part

Pressure switches

Units in stock

0 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.

base code

605.99561

pressure differential (opening/closing)

80/68 Pa

electric charge

1(0.5) A / 250V~

manufacturing batch

UPJEHI

manufacturing date

week 47 of 2008 (47/08)

number marked on the part (does not match the catalog reference)

4000121232

Manuals and technical documentation

Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.

• Vaillant VMW 24/282/4-5 RV Manual (PDF)Document © Vaillant, provided as a technical reference.