View Full Version : SWG..before or after large heater

04-15-2006, 06:01 PM
Hi, SWG gurus,

My heater will be a large water-to-water exchanger that (I hope) will be changing my water temp by 30 degrees F. or so.

It seems if the SWG is installed downstream of that, it will incorrectly sense pool temerature and adjust itself erroneously.

Would you recommend installing before or after the heater?:confused:

Dave S.

04-15-2006, 06:31 PM
Definitely after....the high concentration of chlorine gas will destroy the heater.

04-15-2006, 07:05 PM
Just about every SWG manual that I have ever read suggests placing them AFTER the heater

04-15-2006, 07:38 PM
Yeah, guys, I agree, after the heater makes the most sense.

I am pretty sure they adjust Cl output based on the temp of the water, tho.

I can't figure out how it compensates for "heater on" water of maybe 110 or so and "heater off" water of around 80 or less? :confused:

Dave S.

04-15-2006, 08:27 PM
I believe the adjustment you're referring is for COLD water to prolong the life of the cell. COLD....is tough on the cell so the output is automatically adjusted with roughly 50 deg water or less. You won't notice a difference in 110 vs 80 degrees. My wife cranks our heater and I've never had any problems. Hope this helps, Tony

04-15-2006, 08:39 PM
Hi, Tony,

Yeah, that explains that temp thing. Makes sense. Thank you.:)

Dave S.

04-15-2006, 09:17 PM
my PoolPiliot has it's own temperature/flow sensor right by the chlorine generator.

04-18-2006, 03:19 AM

The Pool Pilot does have a temperature compensation that will increase the output if it senses an increase of water temperature. Note also that most heaters have a 2 - 10 degree temperature split between the inlet and outlet pipes of the heater. This should not fluctuate the Pool Pilot output that much.

04-18-2006, 10:59 AM
Hi, Sean,

Thanks. The reason for my post is this is a REALLY big heat exchanger and, while it is not yet running, I am calculating 20+ farenheit temp changes. Still no issues?


04-18-2006, 11:37 AM
I have an autopilot system. Would it be feasible to move the sensor section between the filter and heater. Replace the sensor section with a piece of pipe and leave the cell after the heater. Just a thought.
You would have to be carefull not to turn off or reduce the flow thru the cell. Since the flow sensor would not be at the cell.


04-18-2006, 05:55 PM
20 degree split on any heater, regardless of heat exchanger size, means insufficient flow through the heater. This can lead to premature damage. Other areas of concern if this is a heat pump is the evaporator coil. Any blockage around the coil will cause inefficiencies and higher temp splits.

splitting the tri-sensor from the manifold....hmmm too risky. All you need is for the cell to be scaled and the tri-sensor to not detect this condition (blockage of flow) and you can have a read disaster. "Don't do it" is my 2 cents, besides, it voids warranty.