Heater bypass effects on IFCS pressure

[bertschb]

Being a new pool owner I've logged some strange data over the past six months that took me a while to explain. One of them was filter and IFCS pressure. I knew pump rpm would have a significant affect on pressure but I didn't realize how much of an effect the heater bypass valve would have.

When we bought our house, the previous owner had the heater bypass valve set at the 50/50 position. At 2,750rpm, filter pressure was 17psi and IFCS pressure was 11. I log this to see how pressures are affected after cleaning the filter cartridges. Today I bypassed the heater entirely and the IFCS pressure jumped from 11 to 17psi! The IFCS jets are really moving some water this morning! I figured changing the heater bypass valve would make a difference but not that much.

When we bought the house the IFCS was set to run for four hours per day. I dropped that to 1.5 hours for a few weeks. Pool was still spotless. After calculating how little it cost to run the pump at the higher speed I use for the IFCS I decided to bump my IFCS run time to two hours. Now after seeing how much better the IFCS water pressure is with the heater bypassed I'm tempted to either drop the pump rpm or run time.

I continue to learn new things about pool ownership each week. Mainly from the amazing folks here but sometimes I stumble on it by myself.

 

[proavia]

Post a pic of your heater bypass setup.
Some have found that allowing the water to flow thru the bypass and thru the heater at the same time allows the most flow downstream of the heater bypass. But this may be dependant on how the heater bypass is installed.

For the IFCS to clean at the lowest rlm, you need the most unrestricted flow to the system - as you have now found out.

 

[bertschb]

Post a pic of your heater bypass setup.

 

[proavia]

So no check valve in the pipe with the red arrow?

Can you set the 3 way valve so OFF is pointed to the upper right (180* from its present setting)? In theory, this should allow most of the water flow to bypass the heater and just a little to flow thru the heater. While you may not notice a flow increase downstream, this should allow a little bit of filtered/chlorinated water to always flow thru the heater.

 

[bertschb]

So no check valve in the pipe with the red arrow?

Can you set the 3 way valve so OFF is pointed to the upper right (180* from its present setting)?

I don't know what a check valve is! More to learn...

I can only rotate the valve 90 degrees clockwise from its current position as shown in the photo above.

 

[proavia]

I don't know what a check valve is! More to learn...

I can only rotate the valve 90 degrees clockwise from its current position as shown in the photo above.

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Allows water to only flow one direction.

That looks like a Pentair 3 way valve. I think you would have to reset the stops on the semi-circular part under the handle. Probably not worth the effort for an unknown minimal gain.