Need help with new spa installaion

[cvaparo]

Hi everyone!!
I am new to pools and new to forums, so please excuse my ignorance.
I have attached a picture of my pump room where I think there is something wrong with the design of the plumbing.
I have a 3 way valve after the pump so only part of the flow will go through the filter/ heat exchanger loop.
I can't get enough flow or pressure through this loop to even activate the flow switch. Is this whole design wrong or is there just that much loss through the exchanger?
[attachment=0:ihchwqae]IMG_0090.JPG[/attachment:ihchwqae]

 

[Bama Rambler]

Welcome to TFP.

Give us a few more details.
What speed are you running the pump?
Is that the heater on the very far right?
Do you have a drawing of the plumbing? (I'm guessing not)
Have you tried to adjust the 3-way valve on top of the pump to send more water to the heater? (Looks like it's about 1/4th to the heater and 3/4ths to the filter, if I'm right).

 

[cvaparo]

I am just starting to figure out what the best speeds are for filtering and heating. 1500 rpm seems to give me a smooth quiet flow with about 1 degree/hr rise from my 52 degree water this morning. Though the flow switch seems too tight to operate at any speed or valve setting.(so I am holding it manually)
You are right , the valve is set 1/4 x 3/4, but the 3/4 is to one loop of filter and heater. The 1/4 is going back to the spa. The filter/heater loop wont pressurize enough to fill the clear covered check valve, which is above the wye on the right side of the picture.
Yes the heater is on the right, a Rinnai tankless boiler with a closed loop header that has one loop for radiant heat, and one through a Flat Plate heat exchanger made for pools.

 

[Bama Rambler]

Is that the filter on the left?

I'm having a hard time figuring out the plumbing. The wye with the check above it makes no sense to me.

 

[cvaparo]

Yes the filter is on the left.
The wye is where the heated water returns back to the spa down through the floor. The check prevents water from pushing backwards through the heater and filter when the 3 way valve is open towards the wye.

 

[Bama Rambler]

What happens if you close the 3-way valve completely going to the spa (right branch)?

If I'm correct, the plumbing loop from the pump going to the left goes through the filter then the heater and through the check valve to the spa. To the right, it goes straight from the pump to the spa, bypassing everything. Is that correct?

 

[cvaparo]

If you close the right branch all the way the flow to the spa almost stops. the pump and the skimmer baskets look stagnant. though there is a very small flow

Oh sorry Dave, you are correct

 

[jblizzle]

Any chance you have the check valve installed incorrectly?

You are going to have a lot of head loss forcing the flow through all that 1"? copper pipe, but the flow should not stop.

 

[cvaparo]

Yes I took it apart to check...a 5lb. spring I think. But shouldn't the pump be able to build pressure
through the plate exchanger? Could it possibly be air bound?

 

[Bama Rambler]

What is the filter pressure gauge reading when you turn the valve each way?
Is the flapper on the check valve to the right or to the bottom port?
Has it ever worked?

 

[cvaparo]

At 1500 rpm the full filter loop setting is 10lbs, full spa setting 1 lb or less
Flapper on right and I just fired this up today. A plumber who had no pool experience set this up

 

[Bama Rambler]

It sounds like the heat exchanger is plugged or stopping flow somehow.

Crank the pump up to 2500 rpm with the valve turned to flow thru the heater and let us know what the filter pressure is?

I can't see well enough to know if there's something turned off.

With the flapper to the right the check valve is installed correctly.

 

[jblizzle]

Why do I not understand what "full filter loop" and "full spa setting" mean? Which way is the handle pointing for each of these?

If the valve handle is pointing to the right, then the filter/heater would be off right and you should read 0 pressure.
If the valve handle is pointing to the left, then the bypass is closed and all the flow should go through the filter/heater and you are reading 10psi, but getting no flow into the pool.

Is that correct?

 

[cvaparo]

Correct, there is flow with the bypass closed but not enough to keep the skimmer basket from floating. There is a drain valve at each side of the plate exchanger in the copper where I shut everything down, hooked a hose to it and water ran through it good. It is 6 gal/min minimum flow to work properly. I thought it might be plugged up with solder or pvc shavings. I also took the new filter apart and everything looked ok. All I can think of is either the pump can't build enough pressure for all that necked down copper with a multitude of bends or I can't get all the air out of it.

 

[jblizzle]

Have you tried turning up the speed yet? The motor should have no problem moving water through the heater (do you have more pictures of the actual heater) and pushing the air out. Seems like something is blocking the flow after the filter.

 

[Bama Rambler]

What's the model number of the boiler?

 

[cvaparo]

It is an RU80I, but the pool water in indirectly heated through a "Flat Plate" heat exchanger. No chlorinated water goes into the boiler.
Flat Plate has a web site for swimming pool applications in the hydronic heating section. I have the 8 plate model for up to 4000 gal pool, with 180 degree boiler temp

 

[cvaparo]

I raised it to 3000 rpm for 10 minutes. The filter pressure goes to 30 but still barely opens the flapper on the check valve

 

[jblizzle]

Is there increase flow in the spa? Does more come shooting out of the drain?

I am amazed that there could be that much pressure and lack of flow without some sort of blockage.

 

[cvaparo]

Thank you both for your interest in this. The only reason I put 3 way before the filter was to attain the maximum flow when I wasn't filtering and heating in order to use it as a swim spa. Maybe the flat plate just slows everything down too much. With the filter/heat loop closed off it just about sucks the skimmer dry at 3000 rpm