Heater bypass

[Splitpi]

Added a heater bypass last night. Used these 2" ball valves.

https://www.amazon.com/dp/B09ZTVF5MV?psc=1&ref=ppx_yo2ov_dt_b_product_details

After the initial movement of the ball, it is very smooth. My only complaint is that the Orings can call out when placing the valve body. But with enough lube, they stick. Valves seem extremely robust. Now I can hunt down the small leak in the heater manifold. Maybe a liter of water every 2 - 3 days. It severely cracked 2 years ago in the Texas freeze and I fiberglass / epoxied it back together. With this years freeze a small crack opened. I have a new manifold, but would rather wait and use as backup.

 

[ajw22]

The problems with using three ball valves for a heater bypass are:

• A misset valve can dead head your pump
• You can trap water pressure in the heater which will engage the pressure switch and allow the heater to run while bypassed

Heater Bypass - Further Reading

www.troublefreepool.com

You should install a flow switch to replace the pressure switch...

Heaters Parts | Heaters | Parts & Accessories | Commercial - Hayward Pool Products

Hayward commercial pool products are supported by a full range of replacement parts and accessories for heaters. Universal H-Series gas heaters combine industry-leading hydraulics,and energy efficiency and reliability, with low-NOx emissions.

www.hayward-pool.com

UHXFSW1930 - H-Series H150-H500 Flow Switch Kit - Hayward

This is a Hayward Flow Switch Kit for the H-Series Low NOx pool heaters, models H150 to H500.

www.poolweb.com

I got lucky...now I need help adding a flow switch

Evening, TFP World! We have an autocover that stays closed except when the pool is in use or needs to be left open to breath. Today, it was a beautiful day, so I left it open most of the day. I did not appreciate how much Crud was coming off the trees, and allowed both skimmer baskets to get...

www.troublefreepool.com

 

[Splitpi]

Interesting. That is a much simpler design with fewer parts.

 

[ajw22]

Interesting. That is a much simpler design with fewer parts.

For a heater bypass all you need is a 3 way diverter valve on the inlet and a check valve on the outlet pipe. The check valve should prevent enough water pressure to engage the pressure switch and run the heater.

To be safe you can still install a Heater Flow Switch - Further Reading

 

[JamesW]

Even with a check valve, there will be enough pressure to close the pressure switch.

Basically, if the pump is on, the pressure switch will close regardless of the valve types or configuration.

With a bypass, the only way to be safe is to add a flow switch.

 

[Splitpi]

@JamesW Do you have a reference to install a flow switch into a non-salt water Aqualink? Basically, trying to figure out the wiring into the control panel so that it shuts off the heater when no flow is detected.

 

[JamesW]

Put the flow switch in series with the heater pressure switch.

 

[ajw22]

The heater flow switch connects in series with the pressure switch in the heater, and does not make any connin the Aqualink.