Irrigation pipes banging when toilet flushed

Help Support Plumbing Forums:

marlonc497

Member
Joined
Jul 19, 2019
Messages
20
Reaction score
3
Location
NY
Thanks for the suggestions, I'll do them as soon as I can. Does anyone know why the backflow valve would chatter continously until I shut the zone or valve down?
 

Twowaxhack

Professional
Professional
Joined
Feb 9, 2021
Messages
4,806
Reaction score
2,141
Location
United states
Thanks for the suggestions, I'll do them as soon as I can. Does anyone know why the backflow valve would chatter continously until I shut the zone or valve down?
Every zone valve or just one ? If it’s just one then it’s a bad zone valve most likely.
 

Twowaxhack

Professional
Professional
Joined
Feb 9, 2021
Messages
4,806
Reaction score
2,141
Location
United states
Choke the outlet of the backflow device going to the zone valves some.

Large inlet pressure drops can cause chattering. By choking the outlet it may help the valve maintain inlet pressure.

Experiment with how much. Monitor for noise.

Also choke the flow rate down on the toilet, make it fill slower.

See if that doesn’t stop the trouble.
 
Last edited:

marlonc497

Member
Joined
Jul 19, 2019
Messages
20
Reaction score
3
Location
NY
Will do, its been raining today so the cycle got canceled but ill monitor it the next time it runs. Thanks!
 

marlonc497

Member
Joined
Jul 19, 2019
Messages
20
Reaction score
3
Location
NY
Quick update, per Twowaxhack's recommendation I choked the outlet of the backflow preventer about halfway and since then I've had no chattering (knock on wood). The backflow preventer still "locks up" for a split second when either zone 1 or 4 turn on so I suspect it must be faulty zone valves closing or opening too quick. Nonetheless the main problem was the chattering and it seems to have been solved. Hoping no one touches the outlet valve now that it's working haha.
 

Twowaxhack

Professional
Professional
Joined
Feb 9, 2021
Messages
4,806
Reaction score
2,141
Location
United states
Thank you for the update. It was a guess on my part so this was definitely a learning experience for me.
 

Latest posts

Top