Should a backwater valve be open or closed?

A normally closed valve stays closed at rest. A normally open valve stays open while water goes down. A CMMTQ plumber picks the type. We clear the line.

Does a backwater valve stop water coming in through the French drain?

No. Water along the walls is the French drain. See clean a French drain and water in the basement.

Will I get the price before the work?

Yes. We give you the estimate over the phone. You approve it before the work. Book your slot online; any extra work is estimated separately. No charges for work you did not approve.

Do you serve my area?

Yes. We serve Greater Montreal, including Montreal, Laval, Terrebonne, and Repentigny. If you are unsure, call 514-700-6731 and we will confirm.

What a backwater valve does in a backup

August 27th, 2026•1 min de lecture

A backwater valve, or anti-return valve, stops sewage coming back from the city into the basement. It does not unclog a drain. If water comes up through the toilet or floor drain, we treat the clog first. Book emergency unclogging. Estimate over the phone.

House valve and normally open valve

The house valve sits on fixtures below street level: basement toilet, floor drain, washer. A normally open valve stays open while flow goes the right way, then closes if the sewer comes back. The City of Montreal describes the duty for new buildings since 2011, and after a backup, on its backflow stop valve page. Check the borough for the permit.

The valve does not replace unclogging

A stuck valve does not by itself explain a slow drain. Grease, paper, and roots stay in the line. We unclog. We camera if the line needs it. We hydrojet if the pipe holds. The valve protects against the municipal network. It does not clean your lateral.

Installation price

We do not sell valve installation as a HydroGo product. For an installation estimate, use a CMMTQ contractor. The City publishes RénoPlex aid examples on the same page. Those are not our rates. Our visit is flow and the cause of the backup.

If water is coming up now, call 514-700-6731 or book emergency unclogging.

Par Benjamin

Questions sur le clapet anti-refoulement

Le clapet anti-refoulement doit-il être ouvert ou fermé?

Un clapet normalement fermé reste fermé au repos. Un clapet normalement ouvert reste ouvert tant que l'eau descend. Un plombier CMMTQ choisit le type. On dégage la conduite.

Un clapet évite-t-il l'entrée d'eau par le drain français?

Non. L'eau le long des murs, c'est le drain français. Voyez nettoyer un drain français et eau au sous-sol.

Aurai-je le prix avant les travaux?

Oui. On vous donne l'estimé au téléphone. Vous le validez avant les travaux. Réservez votre créneau en ligne; tout travail de plus est estimé à part. Pas de frais pour un travail que vous n'avez pas approuvé.

Desservez-vous mon secteur?

Oui. Nous desservons le Grand Montréal, y compris Montréal, Laval, Terrebonne et Repentigny. En cas de doute, appelez le 514-700-6731 et nous confirmerons.

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514-700-6731

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