Huba Control Air Pressure Switch for Vaillant Turbotec Plus VMW 21/245 - 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

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 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 that require diagnosis in the pressure switch 0020041905

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, stops after a few seconds, and needs to be reset to attempt again.

  Cause: The pressure switch does not close the switching contact, and the control board interprets that there is not enough air pressure, cutting off the gas for safety.

  Check that the extractor is spinning normally and that both silicone tubes of the pressure switch are properly connected and not crushed.

• 02

  The display shows a fault warning for the air pressure switch, and in some cases, a lock code also appears on the control.

  Cause: It is the signal emitted by the control board when the pressure switch does not confirm the expected pressure differential during the ignition cycle.

  Before replacing the part, check the flue for possible blockages and clean the condensate siphon if the boiler is a condensing type.

• 03

  After a long period of not being used, like after the summer, the boiler started to show this fault repeatedly.

  Cause: With the boiler off, the silicone tube may have come loose slightly or accumulated dirt, leaving the pressure switch without the pressure it needs.

  Visually check that the pipes are properly fitted at both ends, both at the pressure switch and at the air collector.

• 04

  The fault is intermittent and seems to depend on the wind or the orientation of the flue outlet.

  Cause: This pressure switch operates with a narrow switching margin, so external back pressure can push it out of its range.

  Note if the fault occurs on windy days; if so, check the external flue terminal before replacing the pressure switch.

Vaillant fault codes 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.

Vaillant 0020041905 pressure switch datasheet

Catalogue reference

0020041905

Uniclima internal SKU

PCVTT21/245

Brand

Vaillant

Type of part

Pressure switches

Units in stock

0 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.

Manufacturer

Huba Control

Manufacturer code

605.99880

Pressure differential (open/close)

85/70 Pa

Electric charge

0.2(0.1)A / 30V~

Maximum allowable pressure

1500 Pa

CE marking / notified body

CE 0085 22

Manuals and technical documentation

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

• Vaillant VMW 21/245/4-5 manual (PDF) Document © Vaillant, provided as a technical reference.