Replacement Pump Advice - Compatible with pool heater?

[mpclimber]

I'm a long time lurker but could use some input on a replacement pump for my pool. My existing pump is screaming like a banshee and also leaking from between the motor and pump body (even after replacing the seal), so I think it's time for it to go.

THE QUESTION?
I'm curious about recommended replacements. I'm concerned about (i) keeping a good flow rate because I only have one return and one skimmer and (ii) whether a multi-speed pump would cause issues with my heater (e.g. not enough flow rate to keep it running).

EXISTING EQUIPMENT:
I have a 22,000 gallon 36x18 concrete pool that was built in the 1970s.
It has one return in the center of the shallow end and one skimmer at the deep end. It had a main drain, but it was plugged. The whole system uses 1.5" PVC. The pipe run from the heater output to the return is probably about 40 feet. From the skimmer to the pump is probably only about 6 feet.

The other equipment is:
Filter - Hayward Sand Filter - S270T
Heater - Hayward H400FDN
Chlorination - Stenner Pump

The Existing Pump is a 1HP generic motor on what looks to be a Hayward Super Pump pump body.

CURRENT USAGE:
I'm in NJ, so I only run the pool from memorial day to labor day. I tend to run the pump 8 hours a day (6am-2pm). I use a mechanical instamatic timer. I only run the heater for the weekends, so I'll turn the heater on Friday night and the heater usually brings the temp up about 1 degree an hour. I'd love to save some electrical utility expense, but I've read that the heater has a minimum flow switch, so I'm worried that a two speed or variable speed pump would not work for me.

Anyone have any suggestions? Let me know if there are any other details or info you need.

 

[JasonLion]

Welcome to TFP!

Electrical rates aren't high enough in NJ to justify a large variable speed pump, but a smaller variable speed could be a very good fit. The heater will prevent you from using the very lowest speeds, but you should be able to find a low-mid range speed no problem that works with the heater and saves a great deal on electricity.

Also, you can lower the number of hours you run the pump, which will also save a great deal of electricity. 4 hours a day is enough for nearly all pools.

 

[mpclimber]

My big goal is to run the pump on a shortened schedule during the week and then run the pump and heater for longer periods on the weekend so it is ready to swim on Saturday and Sunday. Do you think I could use a variable speed pump to accomplish this by under-running the flow during M-Fri on a shortened schedule (so that the flow is low enough to cause a flow error on the heater and not activate it) and then run at a faster speed on Saturday and Sunday for a longer duration so the heater runs? Will I damage the heater by using this approach? What's a good variable speed pump that has 7 day scheduling?

The other option is to go with a either a 7 day programmable intermatic timer and manually turn the heater on and off or to go with an iAquaLink setup and program it that way. Thoughts?

 

[JasonLion]

None of the variable speed pumps I know of have 7 day timers. However, most of them are easy to setup using an external 7 day timer, and the 7 day timers aren't too difficult to find. For the timer, something like an Intermatic ET1725C would work. It has separate switches for the pump and the heater.

It is best to have a second method of controlling the heater, in addition to the water flow detection. When the flow/pressure switches are reasonably reliable, you don't really want to depend on that long term, as a failure of that switch could cause the heater to destroy it's self.

An iAquaLink would work, but it is overkill for this situation, unless you have a spa or other water features you haven't mentioned?

 

[mpclimber]

Thanks for the response! I'm starting to lean towards the aqualink because it would be easy to add a profile for "swimming tomorrow" so my wife could quickly switch over the set-up if she schedules an unexpected swimming play date for a weekday. Also, it would be really cool to hook the stenner into it and have a push button way of "shocking" the pool rather than futzing with the independent timer that governs the stenner dosage (right now operating a staggered 1 hour per day to inject roughly 1 gallon of chlorine to maintain target FC levels).