Pump on, Hayward heater off but still noisy.

[Dearoledad]

With filter pump running but the Hayward H400 heater off a considerable water noise is heard at the heater header. This header noise just started after 13 years of use. It is not steam as the heater is off. I have a video so the sound can be heard but couldn't figure out how to attach it to this post.

Bad by-pass valve? Bad thermal control valve? Some other problem? Just an annoyance or needs to be fixed?

 

[ajw22]

I would start with the Bypass Valve or the Thermal Control valve....

https://hayward-pool-assets.com/assets/documents/pools/pdf/manuals/h-series-millivolt-owners-manual.pdf?fromCDN=true

Page 33

 

[1poolman1]

Check for a section leak at the pump. Most noise is air in the system.

 

[Dearoledad]

Thank you for your recommendations.

If I have an air leak, should I see water dripping at leak source? The pool jets are not blowing air bubbles.

When I remove the header at the heater, will I need to replace gaskets or is it a reusable? The task looks pretty simple. Is it?

 

[ajw22]

If I have an air leak, should I see water dripping at leak source? The pool jets are not blowing air bubbles.

A suction side air leak does not drip water out since it is sucking air into the leak. A leak on the pressure side of your pool equipment will leak water out.

Suction Side Air Leaks

If you see air bubbles coming out of the return lines in your pool, you likely have a leak. Some signs that a suction side plumbing leak has occurred include: Read more

www.troublefreepool.com

When I remove the header at the heater, will I need to replace gaskets or is it a reusable? The task looks pretty simple. Is it?

I always like to replace gaskets if I can when opening places like that up.