Heatpump bypass set suggestions and any other input

[FirstVallartaPool]

OK so I did a crude drawing by memory in Google keep. I am not at pool location now but will be in mid July. The heatpump needs to move a couple of feet or so to get more top airflow with a newly constructed deck. It has never had a bypass in its entire 10 year life when installed with new pool. Technically it is not necessary according to the manufacturer (heat siphon) as it is titanium and impervious to any chemical damage as well it is a 100% flow through design. However since we need to move it and reconfigure a few things anyway I'm going to put in some sort of bypass. It is only used at most 2 months of the year due to the climate in Vallarta.
Any thoughts and input would be really appreciated as this is our first pool and I am still getting my head around it.

 

[bdavis466]

Your drawing doesn't really make sense. Are there two separate returns to the pool?

 

[pooldv]

I think the plumbing going to the right goes to waste.

To plumb a heater bypass install a 3way valve where the shutoff is between the filter and heater with one pipe going to the heater and one going to a tee that goes to the return plumbing and the heater output. Put a check valve between the heater and the tee.

 

[FirstVallartaPool]

"Your drawing doesn't really make sense. Are there two separate returns to the pool?"
How so?. There is one line only currently coming off heat pump that goes to 2 return jets on one wall.

"I think the plumbing going to the right goes to waste"




exactly..yes out on right goes to waste and I believe Skimmer basket overflow is what is connected to that waste line from filter as well.
So as in below? The purpose of the check valve is to keep water in the heat pump when bipassed so it doesn't introduce air when 3way turns it back on?

 

[bdavis466]

That diagram is correct except you'll want a check valve on the opposite side of the bypass line right after the heater. You don't need a shut off after the heater and you don't need the check valve before it.

 

[FirstVallartaPool]

OK thanks I can't post final updated sketch to confirm due to over site limit by will post later. I'm pretty sure I get it and makes sense.

 

[pooldv]

Yep, just remove the check valve from the heater inlet pipe and put it on the heater outlet pipe.

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[Pchase]

I had a little variation to this in that I used three 2-way valves. Inlet and outlet and one in the bypass line and just let my system check valve do the job down stream.

When the heater is going to run, the heater inlet and outlet are fully opened and I will partially close the bypass. You can do the exact same thing with the 3-way. When I'm not running the heater, I open the bypass to reduce the head loss. Again, the 3-way will do the exact same thing.

The advantages are the 2-way has a union end and with the union on the boiler connections, I can easily remove the whole pipe sections from each valve to the heater. The heater can be taken out without bringing the system down. Also, I have a cartridge filter, so I can unscrew the inlet section, screw in a discharge hose, close the bypass and I have a pump to waste line.

It's a matter of preference, but the 3-way is probably a little easier for operation and the 2-way arrangement is better for maintenance. I would probably add another valve to the discharge piping so you can run the system if you take the heater out.

 

[bdavis466]

I don't see how you couldn't do the exact same thing with one three way instead of 2 two ways.

 

[Pchase]

I don't see how you couldn't do the exact same thing with one three way instead of 2 two ways.

Theoretically you could, but would be relying on a check valve on the discharge to hold back flow to operate with the heater out of service. I don't think I would trust that and would place another valve for isolation purposes.

 

[FirstVallartaPool]

OK..well all of those shut offs (2ways?) are already in place, although going on 10 years old now. I could move the old shut off to heater outlet just behind the check valve for saftey if I ever fully needed to take out heater and not rely on the new check valve only but I don't really see that as a realistic concern?