Heater Bypass and Other Plumbing Modifications

[W.J.Christy]

I am in the process of installing a heater bypass to help reduce pump speed required for decent flow and decrease the pH rise I get when my heater fully functional (recently my master temp 400 manifold bypass valve bit the big one).

So the question is, do i need a check valve to prevent flow from going backward into the heater?

 

[DrewLG]

do i need a bypass valve to prevent flow from going backward into the heater?

You mean check valve, right?

Maybe I don't understand how your heater bypass would be plumbed, but how would the flow go backward into the heater? Where would it go TO?

 

[W.J.Christy]

You mean check valve, right?

Maybe I don't understand how your heater bypass would be plumbed, but how would the flow go backward into the heater? Where would it go TO?

Yep meant check. Bypass would go directly from outlet of the filter to the swg. Heater would be a separate loop but still connected at the same time.

Set up kinda like attached in the photo.

 

[pjt]

do i need a check valve to prevent flow from going backward into the heater?

Most bypasses are plumbed with a three-way diverter valve before the heater and a check valve on the heater output pipe.

 

[pjt]

Here's a picture of my bypass:

 

[W.J.Christy]

@pjt that's a nice set up. I have seen that used when its desired to be able to completely remove the heater from the circuit.

I am looking more to provide a secondary path for flow. Mostly to gain efficiencies with the pump and to help reduce pH rise. I recently had the manifold bypass valve fail inside the heater which resulted in higher flow rates at lower rpm and a reduction in pH upward creep. Id like to mimic this in a more controlled manner. In larger piping systems i have seen similar things done to limit flow to equipment without a check but am unsure if there would be a negative affect on the heater.

 

[pjt]

You will gain substantial efficiency by using a bypass. For my setup, with the handle at the 9 o'clock position (not pictured) a little water flows through the heater and most of the water follows the path of least resistance and flows through the bypass piping.

 

[W.J.Christy]

Couple questions, are the pentair unions for their pumps, filters, and heaters all the same? I know the SWCG is its special deal, but are the others?

 

[generessler]

Couple questions, are the pentair unions for their pumps, filters, and heaters all the same? I know the SWCG is its special deal, but are the others?

I don't think that's good to assume. My Pentaire Clean & Clear filter and Mastertemp 400 unions sure look different. I don't know if they're thread compatible. Only the latest Pentaire pumps have unions built in. Afaik, the older ones all have a female NPT thread. I used this on my new Intelliflo, which seems to be working well.

 

[W.J.Christy]

I don't think that's good to assume. My Pentaire Clean & Clear filter and Mastertemp 400 unions sure look different. I don't know if they're thread compatible. Only the latest Pentaire pumps have unions built in. Afaik, the older ones all have a female NPT thread. I used this on my new Intelliflo, which seems to be working well.

Yeah, i am worried about the threads size too. Especially since they used something different on the SWCG than anywhere else. Any ideas on where to find the right unions? I found some on Amazon but its hard to tell if they work. I have a set of the ones you linked to. Maybe I will do a fit check.

 

[generessler]

Yeah, i am worried about the threads size too. Especially since they used something different on the SWCG than anywhere else. Any ideas on where to find the right unions? I found some on Amazon but its hard to tell if they work. I have a set of the ones you linked to. Maybe I will do a fit check.

In general, all the Pentaire stuff has reasonably good manuals available on line. At the back of each is an exploded sketch showing all parts. Under the sketch is a table with part numbers. Plug the number into Google, maybe adding "Pentair," but that doesn't even seem necessary.

The exception is that the MasterTemp manual doesn't include the female part of the union. Some digging turned up the part number "PKG 188". Looks like there are many options for buying them.

 

[Turbo1Ton]

The unions are all different. You can order them separately. That is what I did when I replumbed my stuff to add the heater bypass and remove the UV system.

I ordered them from Polytec Pools I think.

--Jeff

 

[W.J.Christy]

You will gain substantial efficiency by using a bypass. For my setup, with the handle at the 9 o'clock position (not pictured) a little water flows through the heater and most of the water follows the path of least resistance and flows through the bypass piping.

As the colder months are on the horizon and I am finally getting around to doing this, I had a question about freeze protection. Has there been any issue with either line freezing due to slow/no flow? I am assuming that the bypassed line would experience stagnant water and could potentially freeze if cold enough.

 

[pjt]

Has there been any issue with either line freezing due to slow/no flow? I am assuming that the bypassed line would experience stagnant water and could potentially freeze if cold enough.

No problems as long as the power stays on and the pump keeps running. Have a plan to quickly drain the water from your pump, heat pump, filter, SWG, and pipes in case the electricity stops.

 

[Turbo1Ton]

Has there been any issue with either line freezing due to slow/no flow?

I haven't had any. I keep mine with split flow so both paths have water flowing.

Like pjt said, make sure you have a plan in place ahead of time for a power outage so you aren't sitting out there in the cold trying to learn where all of your drain plugs are.

--Jeff

 

[W.J.Christy]

So my plan is to install an actuator and link it to the heat command in ET 8 so it fully closes the bypass and forces water through the heater. I think i will adjust the cam in it to only close the bypass valve half way to ensure flow through the heater at all times especially when freeze protection modes kicks in when there is no heat command.