Plumbing advice needed for improving head pressure

[poolhousebythebay]

A year ago I had a Raypak 8450ti heat pump installed. I already had a Hayward propane heater. I wanted to keep both heaters so that I could use the heat pump in the warmer months and use the propane in the winter. We are in Arizona so the winters are mostly mild.

The installer changed the plumbing so that instead of bypassing the heater and returning directly to the pool it now either flows through the Raypak or through the Hayward. This resulted in lowered pressure at the caretaker valve for my infloor cleanning and a dirty pool. So to compensate I increased the rpms of my Pentair Intelliflo VSP to 3000. The caretaker was staying between 14-16 and the floor was getting clean. Unfortunately this pushed the pump too hard and the pump failed and had to be rebuilt. I am trying to find the perfect amount of rpms for the caretaker but I also would like to change the plumbing and reduce the head loss at the equipment. I have reached out to multiple companies and no one is interested in reworking the plumbing, so I am going to DIY.



I have a Pentair EasyTouch 4 for automation.
The pool is 15' X 30', so roughly 15,000gal.
I have ordered replacement popups made by Blue Square Mfg. They are supposed to require less pressure to get the popup to fully extend.

Here is the new pump schedule.
6AM - 10AM = 2750 rpms for cleaning
10AM - 6PM = 1850 rpms for turning over the pool

I am hoping with this new schedule, the new popups and the reconfiguration of the plumbing I will reduce my electricity bill and increase the life of my equipment.

What are your thoughts? Any advice is appreciated. Thank you in advance.

My existing equpment plumbing:

 

[ajw22]

Welcome to TFP. You have a lot to unpack.

First of all a few things about what you said…

A pool does not need any number of turnovers. Read Turnover of Pool Water - Further Reading

A pump should be able to run at its full rated speed for its lifetime. Running a pump at a faster RPM does not stress it more. If your pump failed when you cranked it up to 3000 RPM then it was at the end of its life and was going to fail soon.

A heat pump has more head than a gas heater and will require increased flow. A heat pump has smaller coils in its heat exchanger then a gas heater.

Your current setup has the two heaters in parallel with water flow through the gas heater or HP. You should see a difference in pop up cleaning performance and RPM required between the two.

When you are not heating the pool and when the pop up cleaning system is running which heater is the water flowing through?

Changing the heaters to be in series will increase the head and RPMs needed when you have the heaters in the water loop.

You don’t need both diverters and check valves on the inputs and outputs of your bypasses.

How do you expect your ET4 to control the two bypass diverters in your proposed changes?

A bypass design only needs a diverter on the heater intake and a check valve on the heater output.

What is the % of time you will run your system with…

• Gas heater?
• Heat Pump?
• Both heaters bypassed?

 

[poolhousebythebay]

Thank you for taking the time to provide feedback. I really do appreciate it.

A pump should be able to run at its full rated speed for its lifetime. Running a pump at a faster RPM does not stress it more. If your pump failed when you cranked it up to 3000 RPM then it was at the end of its life and was going to fail soon.
-- I agree. I am not sure why it failed, it was a guess. I do know that if I push it past 3000 rpms, I do not get an increase in gpm just more power consumption.

A heat pump has more head than a gas heater and will require increased flow. A heat pump has smaller coils in its heat exchanger then a gas heater.
Your current setup has the two heaters in parallel with water flow through the gas heater or HP. You should see a difference in pop up cleaning performance and RPM required between the two.
When you are not heating the pool and when the pop up cleaning system is running which heater is the water flowing through?
-- After some trial and error I realized there was difference and changed the diverter to default to propane when not calling for heat. This gave me a 2 psi increase at the caretaker.

Changing the heaters to be in series will increase the head and RPMs needed when you have the heaters in the water loop.
-- This is what I am worried about.

You don’t need both diverters and check valves on the inputs and outputs of your bypasses.
-- My pool is setup with 2 diverters for switching between pool and spa mode. Pool mode runs the the floor cleaning including the ones in the spa. The spa spills over into the pool when in pool mode. In spa mode it is a closed loop dedicated to the spa.

How do you expect your ET4 to control the two bypass diverters in your proposed changes?
-- I have an open relay that I thought might work but to your point I don't know how I would do it. I was hoping it was possible.

A bypass design only needs a diverter on the heater intake and a check valve on the heater output.

What is the % of time you will run your system with…

• Gas heater?
  • This will be used for on demand heating of the spa during Nov-Feb.
• Heat Pump?
  • Heats the pool/spa during the day Mar-May and Sep-Nov. I am going to monitor the temperature more closely this year and update the schedule to heat in the morning to bring up the pool temp and then turn off the heater for the rest of the day,
• Both heaters bypassed?
  • Jun-Jul the heat pump will only be used for heating the spa when needed.

 

[ajw22]

You need a 3 way diverter in the inputs and check valve to prevent backflow on the output….


1 has more head and will need more flow through both heaters

2 has three choices of water paths.

Your current setup has two choices. How is that IntelliValve controlled by the ET?

I doubt your ET can be reliably setup to manage one or two diverters automatically when a heater is selected. An IntelliCenter may be able to do it.