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General Plumbing and Gasfitting Talk => Ask Plumbers (Public) => Plumbing => Q & A - Wetbacks => Topic started by: Jaune on March 29, 2020, 12:36:56 PM

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Title: Wetback noise
Post by: Jaune on March 29, 2020, 12:36:56 PM

Hi all

I have a Rinnai wet back hot water cylinder connected to a Woodsman Tarras 3 wood burner
When the burner is going full steam there is a boom noise coming from either the hot water cylinder or the pipes 
Both of these are about 2 years old as they where installed when the house was built
Now I am no expert in this field but I cant imagine that this would be normal
I have attached a photo of the sticker of the hot water cylinder
Any help or advice on this would be great
Thank you
Jaune

Title: Re: Wetback noise
Post by: Plumber on April 01, 2020, 04:11:27 PM

Hi Jaune,

It sounds like your wetback has a pulse valve to assist the siphon. When the valve heats up the spring is loaded, at a certain temperature there is a tipping point and the release sounds like a bang.  More details here >> http://www.pulseflow.co.nz/

Title: Re: Wetback noise
Post by: Jaune on April 01, 2020, 04:49:26 PM

Hi Plumber

Thank you for that so i assume it is normal then and doesn't pose any danger of blowing the side of my off
 

Title: Re: Wetback noise
Post by: Plumber on April 01, 2020, 05:46:08 PM

Nothing is ever 100%. What im suggesting would be the most common reason for what you are describing. The valve should be visible behind the wetback, to be sure, light the fire and watch it to confirm. Also make sure the wetback is open vented (just to be safe).