New installation - Low pressure from spa jets & heater issue

[newpoolNJ]

Setup Overview:
I have an 18x36 ft pool and an 8x8 spillover hot tub being installed in northern NJ. The system is new. I’ve attached lots of photos.

Equipment List:

• Pump: Pentair IntelliFlo3 VSF (variable speed, set to run pool mode 8 AM–8 PM & spa mode 2 PM–3 PM daily)
• Chlorine Generator: Pentair IntelliChlor IC40 (set to 55% output)
• Valve Actuator: (2) Pentair IntelliValve Valve Actuator (model 521485) to control flow between pool and hot tub
• Automation System: Pentair IntelliCenter (with High-Power Wireless Link Kit, part number 523418, for Wi-Fi connectivity)
• Heater: Pentair MasterTemp 400 (recently installed gas heater)

What Has Transpired:

• Pool and hot tub were filled by water tankers. Salt was added, followed by “Shock-It” treatment, and the IntelliChlor was set to 55% shortly after.
• Installed the IntelliValve to manage flow between pool and hot tub. Initially, one valve always returned to position 0 (even after saving at 24), but resolved with a workaround (saved 0 as home, 24 as secondary). Not sure why this was needed.
• Installed the Wi-Fi module for the IntelliCenter to enable remote control via the Pentair Home app.
• Noticed the hot tub jets have low pressure when the air bubbler is off, feeling much weaker than expected.
• The hot tub uses Waterway Poly Jet housings with Twist-Lock jet inserts (pushed in, twisted to lock). Some inserts twist easily to open/close or adjust flow, but others are very stiff and barely move. The builder applied liquid Teflon to the housing threads (for lock nuts, not inserts).
• Installed the Pentair MasterTemp 400 heater, but it makes a whistling noise and cuts off before reaching the desired spa temperature. Scheduled PSEG to upgrade the gas meter, as I was advised it might be too small.

Flow and Heater Issues I Need Help With:

1. Hot Tub Jets Losing Pressure: When the air bubbler is off, the hot tub jets have very low pressure. The pump speed stays at ~3450 RPM, but the water flow feels weak without air. Is this normal due to the Venturi effect, or could it be a flow issue? Might the IntelliValve position, pump settings, or plumbing be affecting this?
2. Stiff Hot Tub Jet Inserts: Some Waterway Poly Jet Twist-Lock inserts are very hard to twist (for opening/closing or flow adjustment), while others move easily. The builder used liquid Teflon on the housing threads. Could overtightening (due to Teflon) or residue in the Twist-Lock grooves cause this?
3. Heater Issues: The MasterTemp 400 makes a whistling noise and cuts off before reaching the desired spa temperature. Could this be due to insufficient flow (related to jet issues), gas pressure, or a heater problem? PSEG is upgrading the gas meter, but any other ideas?
4. General Equipment Check: Is my setup appropriate for an 18x36 pool and 8x8 spillover hot tub? Equipment:
   • IntelliFlo3 VSF pump
   • IntelliChlor IC40 (55% output)
   • IntelliValve for flow control
   • IntelliCenter with Wi-Fi
   • MasterTemp 400 heater

Appreciate any advice!

 

[ajw22]

Welcome to TFP.

Since you are asking about your heater, show us pictures of your gas meter, the data plates on it, and the gas line connection to the MasterTemp heater.

Is the MasterTemp connected to the IntelliCenter by Fireman's switch or RS-485? Is it setup in the IntelliCenter as Gas Heater or MasterTemp?

 

[newpoolNJ]

Welcome to TFP.

Since you are asking about your heater, show us pictures of your gas meter, the data plates on it, and the gas line connection to the MasterTemp heater.

Is the MasterTemp connected to the IntelliCenter by Fireman's switch or RS-485? Is it setup in the IntelliCenter as Gas Heater or MasterTemp?

It’s MasterTemp in Intellicenter. Confirmed it’s RS-485. Here’s some photos of the gas meter.

 

[ajw22]

Hot Tub Jets Losing Pressure: When the air bubbler is off, the hot tub jets have very low pressure. The pump speed stays at ~3450 RPM, but the water flow feels weak without air. Is this normal due to the Venturi effect, or could it be a flow issue? Might the IntelliValve position, pump settings, or plumbing be affecting this?

How many jets are in the spa?

What is the filter PSI in POOL mode and SPA mode?

What GPM does the IntelliCenter show for the pump at what RPM in POOL mode and SPA mode?

What size pipes were used to the spa jets?

Show us the RETURN and INTAKE valve positions in POOL mode and SPA mode. Four pictures.

1. Stiff Hot Tub Jet Inserts: Some Waterway Poly Jet Twist-Lock inserts are very hard to twist (for opening/closing or flow adjustment), while others move easily. The builder used liquid Teflon on the housing threads. Could overtightening (due to Teflon) or residue in the Twist-Lock grooves cause this?

Has the jets been removed and checked for any debris?

How is water flow without the jets installed?

1. Heater Issues: The MasterTemp 400 makes a whistling noise and cuts off before reaching the desired spa temperature. Could this be due to insufficient flow (related to jet issues), gas pressure, or a heater problem? PSEG is upgrading the gas meter, but any other ideas?

What GPM does the IntelliCenter show when in SPA mode with the heat on?

Do you have a heater bypass installed?

Heater Bypass - Further Reading

www.troublefreepool.com

1. General Equipment Check: Is my setup appropriate for an 18x36 pool and 8x8 spillover hot tub? Equipment:
   • IntelliFlo3 VSF pump
   • IntelliChlor IC40 (55% output)
   • IntelliValve for flow control
   • IntelliCenter with Wi-Fi
   • MasterTemp 400 heater

Your equipment is top of the line.

 

[ajw22]

It’s MasterTemp in Intellicenter. Confirmed it’s RS-485. Here’s some photos of the gas meter.

I cannot read any of the labels on your gas meter...



Your sediment trap is incorrectly installed on the gas line.

Heater Maintenance - Further Reading

www.troublefreepool.com

The correct sediment trap design is for the gas to make a 90 degree turn to go into the heater while the sediment can drop down into the sediment trap as shown in the Pentair diagram below. We see many gas line installations with the gas going straight and the sediment trap on a 90 degree bend. The sediment will not make that turn and continue into the gas valve eventually causing it to fail.

 

[newpoolNJ]

I cannot read any of the labels on your gas meter...

View attachment 645507

Your sediment trap is incorrectly installed on the gas line.

Heater Maintenance - Further Reading

www.troublefreepool.com

The correct sediment trap design is for the gas to make a 90 degree turn to go into the heater while the sediment can drop down into the sediment trap as shown in the Pentair diagram below. We see many gas line installations with the gas going straight and the sediment trap on a 90 degree bend. The sediment will not make that turn and continue into the gas valve eventually causing it to fail.

View attachment 645508

Thanks so much for the quick reply. I will try and get most of your questions answered with some testing tomorrow. Here’s a better photo of the gas meter label.

 

[ajw22]

Here’s a better photo of the gas meter label.

That label is not what I was looking for.

I think this CL 175-250 says your meter is limited to 250 CFM while the heater alone needs 400.

I have a 900 CFM meter in my house for my 400K heater + 250K furnace + gas stove + gas water heaters.

After the new gas meter is installed the dynamic gas pressure should be checked as described in the Installation Manual. The gas valve may have been adjusted to operate the heater with the low gas pressure and will need to be readjusted once the heater is getting more gas flow.

 

[newpoolNJ]

That label is not what I was looking for.

I think this CL 175-250 says your meter is limited to 250 CFM while the heater alone needs 400.

I have a 900 CFM meter in my house for my 400K heater + 250K furnace + gas stove + gas water heaters.

After the new gas meter is installed the dynamic gas pressure should be checked as described in the Installation Manual. The gas valve may have been adjusted to operate the heater with the low gas pressure and will need to be readjusted once the heater is getting more gas flow.

View attachment 645538

Sorry, yes you are correct it’s 175-250. I’ll check with the installer on the valve, seems like it could be a while before the new meter is installed.

 

[newpoolNJ]

How many jets are in the spa?

What is the filter PSI in POOL mode and SPA mode?

What GPM does the IntelliCenter show for the pump at what RPM in POOL mode and SPA mode?

What size pipes were used to the spa jets?

Show us the RETURN and INTAKE valve positions in POOL mode and SPA mode. Four pictures.



Has the jets been removed and checked for any debris?

How is water flow without the jets installed?



What GPM does the IntelliCenter show when in SPA mode with the heat on?

Do you have a heater bypass installed?

Heater Bypass - Further Reading

www.troublefreepool.com

Your equipment is top of the line.

16 Jets are in the spa. 12 jets on one “equal pressure ring” and 4 jets for the feet on another ring.

attaching photos of running in POOL mode

 

[ajw22]

16 jets is part of your problem.

Let's say your pump flows 80 GPM. The 80 GPM is divided among the 16 jets and each jet gets 5 GPM of flow.

For strong jet flow, you need 15-20 GPM, which would require 200 - 300 GPM for 16 jets.

You need multiple pumps servicing groups of jets.

 

[newpoolNJ]

16 jets is part of your problem.

Let's say your pump flows 80 GPM. The 80 GPM is divided among the 16 jets and each jet gets 5 GPM of flow.

For strong jet flow, you need 15-20 GPM, which would require 200 - 300 GPM for 16 jets.

You need multiple pumps servicing groups of jets.

Should I expect a stronger jet flow if I close most of the jets (after resolving why some are stuck) and leave only a few open? That would be fine with me, as it will mainly be just my wife and me using the spa.

 

[ajw22]

Should I expect a stronger jet flow if I close most of the jets (after resolving why some are stuck) and leave only a few open? That would be fine with me, as it will mainly be just my wife and me using the spa.

Give it a try. It should.