Frequently asked questions

Payment

Which payment methods do you accept?

Bank card (Visa, Mastercard, American Express), PayPal, cheque, bank transfer and administrative purchase order for French public bodies.

Is my payment secure?

Yes. All transactions are carried out under strict confidentiality with SSL/TLS encryption. No bank details are stored on our servers.

Do prices include VAT?

Yes, all our prices are shown including all taxes. Any shipping costs are displayed before you finally confirm your order.

Delivery

Where do you deliver and how long does it take?

We deliver to mainland France, Corsica, Monaco and the European Union. Delivery to the European Union costs from €4.99 to a relay point and €7.99 for home delivery (UPS Standard); express delivery is also available.

How can I track my order?

A confirmation email summarises your order, then an email with the tracking number is sent as soon as the carrier collects the parcel. You can also find your full order history in your customer account.

Orders & quotes

Can I order as a professional?

Yes. Installers, plumbers, architects and resellers benefit from tailored conditions. Contact us via the contact form or at domux@casabill.com for a personalised quote.

How does the administrative purchase order work?

French local authorities and public bodies can pay by administrative purchase order: place the order in your account, choose "Payment by administrative purchase order" and enter your purchase order number. The detailed guide is available on the page Payment by administrative purchase order.

Returns & warranties

What is the withdrawal period?

You have 14 calendar days from receipt to return an unused product in its original packaging. Products that have been cut or made to measure are not covered by the right of withdrawal. Contact our customer service to obtain a return form.

What warranty do DOMUX products have?

Products are covered by the legal guarantee of conformity and the guarantee against hidden defects. If you notice a defect, contact customer service with your order number and photos of the product.

Our products

How do I choose the diameter of my vent grille or ventilation valve?

The diameter is that of the duct the product is fitted to: DN80, DN100, DN125, DN150, etc. If in doubt, our customer service can advise you on +33 9 72 53 57 57, Monday to Friday, 9 am to 6 pm (French time).

Are your vent grilles suitable for outdoor use?

Stainless steel grilles with insect mesh are designed for facade mounting and withstand bad weather. For indoor use, choose the white lacquered steel models.

Installation & ventilation

How do I install a ventilation valve?

Make an opening in the ceiling or wall at the nominal diameter of the duct (DN100, DN125 or DN150), insert the spigot, fix the valve and adjust the airflow. Follow our valve installation guide.

Which duct diameter should I choose?

The diameter must be the same along the whole run and suited to the airflow: DN100 up to 60 m³/h, DN125 up to 110 m³/h, DN150 above that. See choosing airflow and diameter.

How do I clean a vent grille?

Every 6 months, with warm water and washing-up liquid, no abrasive products, checking the insect mesh and the adjustment flap: maintenance guide.

My ventilation is noisy or no longer extracts: what should I do?

In 9 cases out of 10: clogging, a crushed duct or no air transfer between rooms. Full diagnosis in the ventilation troubleshooting tutorial.

More guides : see the DOMUX help centre and the technical ventilation FAQ.