Brand new Pentair Heat Pump

[Yeshelloo]

Hello all, I’ve got a brand new Pentair Heat Pump (Ultratemp 110) that I’ve got hooked up and is operating and heating the pool; however, when the pool pump is on and the heat pump is off, there is a consistent knocking noise coming from within the plumbing of the heat pump. Has anyone ever experienced anything similar to this?

My pool pump is a single speed pump and seems to really move a lot of water through the lines quickly, pressure on the filter is typically around 18-20 psi even when the cartridge is clean. Suction and return lines are 1.5” and the pump is listed as 1.25 THP. Pool is kidney shaped, about 3.5 feet shallow end and just over 6 feet deep end. I believe total gallons are somewhere around 12k-14k. Any advice to remediate this would be greatly appreciated. (I’m thinking my pump is oversized).

 

[ajw22]

Welcome to TFP Y.

Ultratemp manual is here --> https://www.pentair.com/content/dam...Pump_Installation_and_Users_Guide_English.pdf

Install a bypass loop with a Jandy valve and you adjust the flow through and around the heater core by the position of the valve. Less expensive then getting a new pump. Although s VS pump is likely to pay for itself in energy savings in a year or two.

See page 4

Automatic Flow Control Valve
The inlet/outlet header of the heat pump comes equipped
with an internal automatic flow control valve. The
automatic flow control valve maintains the proper flow
through the heat pump at rates up to 120 gpm (456 lpm).
If the filter system flow rate is higher than 120 gpm (456
lpm), install a manual bypass valve, see image below.

Note: Be advised that if your circulation pump is over 2
HP or if the total flow exceeds 120 gpm (456 lpm), you
will have to add an external bypass valve. Excess water
flow will damage the heat exchanger.

If you are going to stick around here please put details of your pool in your signature. It will allow us to give better advice.

 

[JamesW]

That's the motor. What does the label on the pump say?

Do you have a picture of the system?

Does it only knock when the heat pump is off?

Are the inlet and outlet correct?

 

[Yeshelloo]

Welcome to TFP Y.

Ultratemp manual is here --> https://www.pentair.com/content/dam...Pump_Installation_and_Users_Guide_English.pdf

Install a bypass loop with a Jandy valve and you adjust the flow through and around the heater core by the position of the valve. Less expensive then getting a new pump. Although s VS pump is likely to pay for itself in energy savings in a year or two.

See page 4

Automatic Flow Control Valve
The inlet/outlet header of the heat pump comes equipped
with an internal automatic flow control valve. The
automatic flow control valve maintains the proper flow
through the heat pump at rates up to 120 gpm (456 lpm).
If the filter system flow rate is higher than 120 gpm (456
lpm), install a manual bypass valve, see image below.

Note: Be advised that if your circulation pump is over 2
HP or if the total flow exceeds 120 gpm (456 lpm), you
will have to add an external bypass valve. Excess water
flow will damage the heat exchanger.

If you are going to stick around here please put details of your pool in your signature. It will allow us to give better advice.

Hey, thank you for your reply and identifying this section. I was looking through the troubleshooting section and couldn't find anything about the knocking but based on the amount of water moving through the return lines, this is what I suspected. I think I'm just going bite the bullet and buy a VS pump because it will pay for itself in a short period of time and I'd rather not add a bypass if possible. Plus, with the amount of water my current pump is moving, my pool looks like a whirlpool so I can only imagine how much extra energy it is using. I will update my profile because I do plan to stick around, just moved into my house a year ago and still have a lot to learn about the pool.

 

[ajw22]

You should have a heater bypass valve anyway. It lets you take the heater out of the water loop for maintenance or when your pH may be questionable. Everything else in your plumbing is PVC or plastic except for the heater. Being able to take the heater offline can be very helpful.

 

[Yeshelloo]

You should have a heater bypass valve anyway. It lets you take the heater out of the water loop for maintenance or when your pH may be questionable. Everything else in your plumbing is PVC or plastic except for the heater. Being able to take the heater offline can be very helpful.

I hadn't thought about that, but totally makes sense. In regards to changing out my pool pump, have you had any experience with different VS pumps that you'd think are better/worse than others? Right now I have a manual switch to turn my pool pump on and off and a cartridge filter, everything has been inherited from the previous owners and I'm considering what my options are for upgrading down the road. Will have some pictures of the setup soon.

 

[Yeshelloo]

That's the motor. What does the label on the pump say?

Do you have a picture of the system?

Does it only knock when the heat pump is off?

Are the inlet and outlet correct?

Thanks for your reply. I am working on getting some pictures; however, I don't know if my pump actually has any labeling on it. The entire setup seems pretty old.

Only real noticeable knock is when the pump is off, as ajw pointed out, it sounds like there is too much flow which is what I expected.

Inlet and outlets are correct.

 

[ajw22]

You have a Pentair heater. If your path over time is to install a SWG and automation then I recommend you stay with Pentair. Pentair Intelliflo 011018 or 011028 (is the new model that should be in the supply chain soon) is a workhorse VS pump that can be setup through its own display and connected to Pentair automation.

A VS pump should be continuous powered and should have a surge protector to protect the electronics.

 

[Yeshelloo]

You have a Pentair heater. If your path over time is to install a SWG and automation then I recommend you stay with Pentair. Pentair Intelliflo 011018 or 011028 (is the new model that should be in the supply chain soon) is a workhorse VS pump that can be setup through its own display and connected to Pentair automation.

A VS pump should be continuous powered and should have a surge protector to protect the electronics.

Thanks for the info, really do appreciate it. For the pump portion, other that the programmable unit that is on the VS units, do you have a separate panel that controls your system? Also, with the pumps costing $1,000+, they really are that much more efficient that they are worth the price? In regards to surge protection, I have a whole home surge protector, do you think that would suffice, or should the pool equipment have its own protection? Also, here are a pictures of the current setup, please keep in mind this is what came with the house (not including heat pump).

 

[Yeshelloo]

That's the motor. What does the label on the pump say?

Do you have a picture of the system?

Does it only knock when the heat pump is off?

Are the inlet and outlet correct?

James, I've attached some additional pictures of my current setup above.

 

[ajw22]

An automation system like the Pentair Easy Touch or Intellicenter gives you a separate panel to manage your VS pump, heater, SWG, lights, etc. Otherwise the pump has a display panel to use. The new 011028 pump display is rotateable and can be removed and wall mounted near the pump.

You should have a surge protector near the pump electrical feed. You don’t know where the surge may enter the house. If it comes in through other then your main feed your whole house surge protector may not catch it. Think lightning strike near your pool equipment.

A SS pump running at 3400 rpm can cost $250/mo to run 24/7. A VS pump can run at 1500 rpm 24/7 for $25/mo. You can get payback on your VS pump in a few months. With a heat pump you will need to run the pump for long periods of the day. Chart showing savings here Switching to a VS pump

 

[Yeshelloo]

An automation system like the Pentair Easy Touch or Intellicenter gives you a separate panel to manage your VS pump, heater, SWG, lights, etc. Otherwise the pump has a display panel to use. The new 011028 pump display is rotateable and can be removed and wall mounted near the pump.

You should have a surge protector near the pump electrical feed. You don’t know where the surge may enter the house. If it comes in through other then your main feed your whole house surge protector may not catch it. Think lightning strike near your pool equipment.

A SS pump running at 3400 rpm can cost $250/mo to run 24/7. A VS pump can run at 1500 rpm 24/7 for $25/mo. You can get payback on your VS pump in a few months. With a heat pump you will need to run the pump for long periods of the day.

Good to know, I will look into adding a surge protector near the equipment as well.

I knew I needed to run the pump a lot for the pool heater, but that's a huge price difference. I'm in the process of adding solar panels to my house with the hopes I can bring my electric bill to a minimum, so I think adding a VS pump has now been brought to the top of the list. Thanks so much for the info. Looking at the prices for a separate automation system, for the current setup I have with my pool, I don't think I can justify that cost yet, but it really would be nice to control everything from inside.

Again, thank you so much for all your help and information, it's been so insightful.

 

[ajw22]

Solar still requires long pump run times. When your solar heat is on you will need more flow and faster rpm. Most folks with solar, and heat pump, and VS pump have automation and valve actuators to change the pump speed, valve settings, and equipment settings for no heat, heat pump on, solar on, etc. And to switch automatically from solar to heat pump and back.

Reread your post again and sounds like you are adding PV solar electric and not pool water heat solar. Never mind.

 

[Yeshelloo]

Solar still requires long pump run times. When your solar heat is on you will need more flow and faster rpm. Most folks with solar, and heat pump, and VS pump have automation and valve actuators to change the pump speed, valve settings, and equipment settings for no heat, heat pump on, solar on, etc. And to switch automatically from solar to heat pump and back.

Reread your post again and sounds like you are adding PV solar electric and not pool water heat solar. Never mind.

Yeah, my apologies, should have been more clear, you are correct, I'm adding PV solar to the house.

 

[JamesW]

The flow from that pump should be within the specifications of the heat pump. So, I don't think that it's an excessive flow issue. Do you have a video of the knocking?

 

[Yeshelloo]

The flow from that pump should be within the specifications of the heat pump. So, I don't think that it's an excessive flow issue. Do you have a video of the knocking?

I do, it's attached in this YouTube link:

 

[JamesW]

The only thing that I can think of that would bang like that is the check valve on the internal bypass, but I don't know why it would bang like that.

Are you sure that the knocking completely goes away when the heat pump is heating or does the sound of the fan and compressor mask the knocking?

Maybe consider a warranty claim to get it checked out.

Who installed the heat pump?

 

[Yeshelloo]

The only thing that I can think of that would bang like that is the check valve on the internal bypass, but I don't know why it would bang like that.

Are you sure that the knocking completely goes away when the heat pump is heating or does the sound of the fan and compressor mask the knocking?

Maybe consider a warranty claim to get it checked out.

Who installed the heat pump?

That's what I was thinking is that it's the check valve making the noise and I was wondering if it has something to do with the rate of water flowing through it. When I restrict the water flow by closing the skimmer valve and have it try to pull through the vacuum line, the knocking slows down and eventually stops.

I think that there may be some knock when it's on but it's hard to hear over the system operating.

So the back story on this heat pump is that it was manufactured in September 2018, I got it off of Craigslist for $250 from someone that had just built a house. The flow sensor was faulty and not working properly resulting in him getting a low flow alarm. Rather than replace the part, the construction company replaced the entire unit and left this one at the guys house. His HOA was going to start fining him for it because it was sitting in the yard, he threw it up on Craigslist which is how I ended up with it. An electrician friend of mine helped with the electrical part and I'm an advance DIYer so together we did the install. Since that's the case, as of right now, the warranty information has not been filed with the manufacturer.

 

[ajw22]

The heat pump is a reverse AC unit. Have you had the pressures and refrigerant levels checked?

I would remove the side panels if you can and then can better listen and identify which internal component the knock is coming from. It should be more obvious if it is coming from the water pressure control valve or the compressor.

 

[JamesW]

There is a check valve on the pvc line coming out of the heat pump with a clear lid. Look in the clear part to see if the flapper is banging. Is the check valve pointing in the right direction?