Return Pump Question

[sp1187]

greetings.

if I run two return pumps, are I adding their gph output to get a total? or is there fuzzy math involved?

 

[Fritzhamer]

I've never seen someone use two pumps and it make sense to me. It always seemed like they were running two pumps just to run two pumps. I would use one pump that will push a little more than you need it to with head loss calculated.

 

[sp1187]

i want to have two separate returns, without ying off one pump, and also want to make sure I have one running at all times when one fails while I'm away.

 

[Fritzhamer]

I hear ya, I too have always had a backup pump because I'm paranoid and believe in being ready. I still have it twelve years later. I've changed my main pump so many times I now have a closet of backup pumps. I've yet to have any of them fail on me. I know it can happen but I don't think it's that widespread.

That being said I'm all about redundancy but also in keeping things simple. I don't have a dual overflow but if I did I'd never consider two pumps. I was planning a 180 a few years back and was going to run both drains to the basement (herbie on both) and a single pump back to the tank with four outputs.

With union fittings it's easy to swap a pump out. A much more likely catastrophe is a downed power line, for me anyway. While I don't believe in two simultaneous pumps I do have two battery backups on each of my circ pumps and apex.

 

[LobsterOfJustice]

If you plumb them back to the tank completely separately, you just add the GPH. This is the most efficient way to do it. If you tee the pumps together, there will be efficiency loss. Only do this if you have to. I run two return pumps this way because I have a single line run under the house but wanted the added redundancy of two pumps. The pumps are plugged into separate circuits and if one pump fails the tank will still receive 2/3 of its normal flow from the other pump until I intervene. I can adjust the apex programming remotely to make up the difference (pumps are DC and running at less than full power) until I am able to swap out the failed pump. If you have to tee the pumps together, use a wye fitting, not a tee, and upsize the pipe when you combine the two lines into a single line. You also need a check valve on the outlet of each pump before the lines join.

 

[sp1187]

thanks for the answers.