Adding manual by pass to Master Temp 400

[jdlangley1]

Has anyone added a manual by pass to their master temp 400 after pool was built. This was not something I thought of during build and was not offered by builder. Just started thinking about it as I have to run my pump at 1800 rpm to satisfy flow switch on swcg. Would be nice to be able to lower rpm to around 1200 and run pump 24/7.

So I started looking at manual by pass info in the pentair manual. Considering adding but not sure if I have the room to do so.

Another question would be around always making sure valve is open when heater is operating. Can I program manual by pass actuator in ScreenLogic to open when I turn heater on?

 

[1poolman1]

Never understood why a bypass would be needed. At low speed, there is virtually no added head caused by a modern heater. That being said, you can add it any time, but your plumbing does not look like it would be easy as it wasn't planned for from the initial install. Doable, but not easy.
For the sake of your plumbing (and appearance, though those are some very clean glue joints), it would be good to get some +/- $1.00 an can flat or satin black Home Depot spray paint and paint the pipes. They can get sunburned if left white, especially in the Texas' sun.

 

[generessler]

My Mastertemp 400 caused a 5 psi pressure increase when I had my old single speed pump. It's lower with a VSP at modest speed, but my flow meter says it still costs about 8 gpm, so I do use the bypass to get the most of of the power investment. (We don't use the heater except to heat the spa now and then.)

It had the bypass when we took ownership, but I had to rejigger plumbing because the SWG was installed before the heater. Installed a new valve at that time.

It does look like you'll need some re-routing to fit a valve in that space. It's hard to see how much from the angle of the photo.

 

[ajw22]

You need to redo some of your piping to fit in a heater bypass. If you post full pictures of your equipment pad we can help think about different routing of the pipes.

You can squeeze a heater bypass into a tight spot. Below is my heater bypass. The problem with the way it was installed is the check valve cannot be replaced. I am going to need to redo it to replace the CV.

 

[JamesW]

Another question would be around always making sure valve is open when heater is operating.

Can I program manual bypass actuator in ScreenLogic to open when I turn heater on?

The actuator plugs into the heater.

It says Intellivalve, but a regular valve actuator should also work.

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/parts-sheets/heaters/pentair_heater_auto_bypass_valve_replacement%20_kit.pdf

https://www.pentair.com/content/dam/extranet/nam/pentair-pool/residential/heaters/mastertemp/manual/Manual-MasterTemp-472592-English.pdf

 

[W.J.Christy]

I am thinking about this as well. If i do install one it would purley be for efficiency sake and not to eliminate the heater completely. The issue with texas is how cold it may get and the need to go into freeze protection mode. The water would still have to flow through the heater in this event meaning the heater could only be partially blocked off. My plan was to forgo the check valve and install an actuator on the bypass valve set to be either 100% heater when in spa mode or 50% heater 50% bypass when in every other mode. That way I could negate the possibility of freezing pipes.

Something to think about.

 

[ajw22]

The actuator plugs into the heater.

That feature is only on the boards of the "connected" heater that has six buttons.

If you have a five button keypad you have an old board without that feature.

 

[JamesW]

 

[jdlangley1]

Let me know if these pics help. If not, I’ll grab ladder after work and take a pic from above.

I have plenty of space on side of booster pump to slide equipment done and make more room, but that would require redoing connections for filter and pump.

**** chlorine feeder is not in use. I need to remove it.

 

[jdlangley1]

Any harm in installing bypass right at filter outlet?

I’m terrible at drawing but envision a three way valve right off of filter. Seems like I’d have room there. And have bottom of the three way go to heater and then have the other side of three way routed to swcg piping. I’d have to redo swcg piping so that I can install check valve between heater and swcg.

Additionally, is it best to keep some water flowing through heater to prevent stagnant water sitting in heater?

 

[1poolman1]

Any harm in installing bypass right at filter outlet?

I’m terrible at drawing but envision a three way valve right off of filter. Seems like I’d have room there. And have bottom of the three way go to heater and then have the other side of three way routed to swcg piping. I’d have to redo swcg piping so that I can install check valve between heater and swcg.

Additionally, is it best to keep some water flowing through heater to prevent stagnant water sitting in heater?

Anywhere after the filter and before the heater is fine. Water sitting in a heater will get somewhat stagnant, but the real danger is that it will evaporate. When it does, it is just the water that goes away. All the "stuff" in pool water gets left behind, coating the inside of the heat exchanger.
The amount of head your heater introduces to a system at low waterflow speeds is negligible.
Unless you add an actuator to the valve and program it into your automation, you would have to manually remember to go to the pad and open the flow to the heater when you want to use it.
Pentair says they make a kit to automate this process, 462048. You can find instructions online, but can't find one anywhere. The only online store that even had one listed, though not in stock was at a staggering price, $850+