Pool pump energy usage

[JoyfulNoise]

To be fair, my installer said something similar regarding the anode. I asked for it based on everything I read claiming salt generators would cause corrosion to the heater. I figured it couldn’t hurt to add it. I also asked for it installed sideways or downwards but they were concerned it would be more likely to leak installed that way. Is the info about heat exchanger corrosion BS?

Corrosion is caused by poor water chemistry and, specifically, low pH. “Salt” has nothing to do with it. Your pool’s salinity is roughly 10% the salinity of seawater and even at 3600ppm it would still be considered only mildly brackish by the standard definitions of salinity. Pool builders and rando facebook internet “experts” love to state that salt water causes corrosion and make a big fuss about it without any proof otherwise. And, for all the people that hate on salt, guess what - every pool is a salt water pool because the chemicals and people we put in to the pool add salt. All chlorine based chemicals, both sanitizers and acid, end up as chloride eventually. So most pools will naturally have a salinity above 1000ppm and some get even as high as 2000ppm all on their own. So the idea that adding salt to water and using an SWG is somehow the death of a pool is bogus.

As for heaters, they corrode from bad water chemistry and, specifically, the improper use of trichlor pucks. Whenever TFP gets a new post from someone about how their heater is corroded and leaking, almost 99% of the time when they are asked for pictures you see a puck feeder sitting right after the heater in the plumbing. And, usually, when you dig in further you’ll find that they use a pool service and the pool guy adds chemicals directly to the skimmer or leaves pucks in the skimmer. The acidity of those trichlor pucks can not be overstated enough and trichlor feeders were never meant to be used on residential pools.

You have a heat pump. Most modern heat pumps use titanium tubing as the heat exchanger and so it is far less prone to corrosion than copper. Also, even if you put zinc and titanium in a galvanic couple, nothing will happen because titanium is not electro chemically active. It builds up a very strong and adherent oxide layer on the surface that will not conduct any electrical current. So the zinc anode does nothing for your heaters titanium heat exchanger.

So, at the end of the day, that zinc anode really isn’t doing anything useful but chemically corroding and throwing off scale into the plumbing. That may or may not be an issue but it is, at best, nothing more than a placebo. If you want to keep it there, fine, it’s not causing any chemical problems. But they are really not worth it or necessary to install.

 

[ajw22]

To be fair, my installer said something similar regarding the anode. I asked for it based on everything I read claiming salt generators would cause corrosion to the heater.

You did not read that here.

I figured it couldn’t hurt to add it.

It does not if installed correctly.

The picture you posted does not have the anode wired to the bonding wire. With no electric connection the anode is a lump of coal.

I also asked for it installed sideways or downwards but they were concerned it would be more likely to leak installed that way.

Sounds like your installer knew less about it then you.

Is the info about heat exchanger corrosion BS?

Yes.

 

[CausticMeasures]

Corrosion is caused by poor water chemistry and, specifically, low pH. “Salt” has nothing to do with it. Your pool’s salinity is roughly 10% the salinity of seawater and even at 3600ppm it would still be considered only mildly brackish by the standard definitions of salinity. Pool builders and rando facebook internet “experts” love to state that salt water causes corrosion and make a big fuss about it without any proof otherwise. And, for all the people that hate on salt, guess what - every pool is a salt water pool because the chemicals and people we put in to the pool add salt. All chlorine based chemicals, both sanitizers and acid, end up as chloride eventually. So most pools will naturally have a salinity above 1000ppm and some get even as high as 2000ppm all on their own. So the idea that adding salt to water and using an SWG is somehow the death of a pool is bogus.

As for heaters, they corrode from bad water chemistry and, specifically, the improper use of trichlor pucks. Whenever TFP gets a new post from someone about how their heater is corroded and leaking, almost 99% of the time when they are asked for pictures you see a puck feeder sitting right after the heater in the plumbing. And, usually, when you dig in further you’ll find that they use a pool service and the pool guy adds chemicals directly to the skimmer or leaves pucks in the skimmer. The acidity of those trichlor pucks can not be overstated enough and trichlor feeders were never meant to be used on residential pools.

You have a heat pump. Most modern heat pumps use titanium tubing as the heat exchanger and so it is far less prone to corrosion than copper. Also, even if you put zinc and titanium in a galvanic couple, nothing will happen because titanium is not electro chemically active. It builds up a very strong and adherent oxide layer on the surface that will not conduct any electrical current. So the zinc anode does nothing for your heaters titanium heat exchanger.

So, at the end of the day, that zinc anode really isn’t doing anything useful but chemically corroding and throwing off scale into the plumbing. That may or may not be an issue but it is, at best, nothing more than a placebo. If you want to keep it there, fine, it’s not causing any chemical problems. But they are really not worth it or necessary to install.

Thanks, yes there was a puck feeder in the old system. Glad to hear if I’m doing the right things corrosion shouldn’t be a concern.

 

[CausticMeasures]

You did not read that here.



It does not if installed correctly.

The picture you posted does not have the anode wired to the bonding wire. With no electric connection the anode is a lump of coal.


Sounds like your installer knew less about it then you.


Yes.

Yes I most likely read it elsewhere and panicked about potentially ruining an expensive piece of equipment. Unfortunately I don’t think I found this website until after we had the new equipment installed.

The bonding wire connection was added by an electrician after the equipment installation was completed. Based on everyone’s feedback I’ll most likely remove the anode when we open the pool in spring.

 

[mas985]

Don’t believe the plumbing or filter are restrictive or undersized. I upgraded the electrical to 100 amps to handle the heat pump. Hoping I can squeeze a larger pump in there if needed.

That looks to be 1.5" plumbing which for any pool built today is undersized.

I know at full speed the filter pressure was around 16 psi with fresh DE powder. I think it was around 12 psi at 80%.

How high is the filter gauge relative to pool water level?

What is the distance from the pool to pump?

What is the exact model # of the heat pump?

According to this data, it looks like all can operate down to 20 GPM. So there may be something else going on here.

XL Series Heat Pump Pool Heater | AquaComfort Solutions

AquaComfort has perfected the science of pool heating with the XL Series pool heater, engineered to capture more of the free heat from the surrounding air.

aquacomfort.com

 

[mas985]

Besides the above questions, can you also post a recent picture of the pad equipment with everything installed?

 

[proavia]

Install a heater bypass - this will allow a lower rpm while still satisfying the SWG flow switch whn not needing to use the heater.

Heater Bypass - Further Reading

www.troublefreepool.com

Cut out the zinc anode - it won't provide any benefit. Use it as a paper weight or door stop.

Use your K-2006C to maintain your pool water to TFP recommendations.

 

[Bill1974]

You said the heater will stop working when the pump is operated at less than 80%. Was it becuase of low flow or you just assumed it was low flow? Adjustment of a pressure switch might be needed.

As was stated early on installing a flow meter, and some pressure gauges will help figure out solution. They will also help in the future to know when to clean the filter and when something is not working as it should.

The plumbing does look like 1-1/2", you can check the fittings they usually have the size marked on them. It does not look like it should be overly restrictive.

If you need to run the pump at 80% to get 20-30 gpm through your heat pump to get it to run, I doubt 1-1/2" plumbing is the issue. Is it possible that you have a collapsed line or obstruction on the suction side and that is chocking off the flow? (this is where a flow meter and pressure gauges would help).

 

[1poolman1]

To be fair, my installer said something similar regarding the anode. I asked for it based on everything I read claiming salt generators would cause corrosion to the heater. I figured it couldn’t hurt to add it. I also asked for it installed sideways or downwards but they were concerned it would be more likely to leak installed that way. Is the info about heat exchanger corrosion BS?

Average salinity of pool water with an SWG is 3000 to 3500ppm. Average salinity of human tears - 10,000ppm. Unless you believe tears could cause corrosion to your heat exchanger, anyone saying that the salt level required for an SWG will do so is trying to sell you something you don't need.

Even pools without an SWG usually have a salinity in the range of 2000ppm or higher after they have been in use a while and any form of sodium-based chlorine (liquid or tablets) has been used. Was very surprised to learn that 25+ years ago when I first started installing SWG and almost put too much salt in a pool. Learned how important testing is to the proper operation of the system.

 

[CausticMeasures]

That looks to be 1.5" plumbing which for any pool built today is undersized.


How high is the filter gauge relative to pool water level?

What is the distance from the pool to pump?

What is the exact model # of the heat pump?

According to this data, it looks like all can operate down to 20 GPM. So there may be something else going on here.

XL Series Heat Pump Pool Heater | AquaComfort Solutions

AquaComfort has perfected the science of pool heating with the XL Series pool heater, engineered to capture more of the free heat from the surrounding air.

aquacomfort.com

You may be right. The pool was built in the late 90s, not sure if standard pipe diameter has changed since then? The equipment pad is likely 3-4 ft higher than the pool and the gauge is at the top of the filter so I would say it’s approximately 5-6 ft above the water line. The pad is approximately 20 ft from the pool. The heat pump model is ACT-1250. I don’t have any updated pictures of the equipment pad but will try to get one today.

 

[CausticMeasures]

You said the heater will stop working when the pump is operated at less than 80%. Was it becuase of low flow or you just assumed it was low flow? Adjustment of a pressure switch might be needed.

As was stated early on installing a flow meter, and some pressure gauges will help figure out solution. They will also help in the future to know when to clean the filter and when something is not working as it should.

The plumbing does look like 1-1/2", you can check the fittings they usually have the size marked on them. It does not look like it should be overly restrictive.

If you need to run the pump at 80% to get 20-30 gpm through your heat pump to get it to run, I doubt 1-1/2" plumbing is the issue. Is it possible that you have a collapsed line or obstruction on the suction side and that is chocking off the flow? (this is where a flow meter and pressure gauges would help).

The heater shuts down and displays low flow error code. It’s good to hear the pipe size hopefully isn’t the issue. Anything is possible with regards to obstructions or a collapsed line.

I suspect there is a leak in the plumbing somewhere based on water loss last season but haven’t attempted anything other than a bucket test and a dye test around the skimmer and return jets. My suspicion was the return side. Would a leak on the return side affect power consumption?

We plan to replace the liner next season and the current liner has a massive tear near the water line (poorly patched) so I’ve been trying to convince myself the liner will solve that problem

 

[mas985]

You may be right. The pool was built in the late 90s, not sure if standard pipe diameter has changed since then? The equipment pad is likely 3-4 ft higher than the pool and the gauge is at the top of the filter so I would say it’s approximately 5-6 ft above the water line. The pad is approximately 20 ft from the pool. The heat pump model is ACT-1250. I don’t have any updated pictures of the equipment pad but will try to get one today.

Based upon that information, the flow rate should be around 50 GPM @ 54' of dynamic head when at full speed.

At 80%, the operating point should be about 40 GPM @ 34' of dynamic head. So well above 20 GPM threshold. I suspect the issue might be that the HP pressure sensor is not adjusted properly to allow for lower flow rates.

Overall though, the head loss is very high but consistent with 1.5" plumbing and a heat pump. One of the downsides of a heat pump.

 

[CausticMeasures]

Based upon that information, the flow rate should be around 50 GPM @ 54' of dynamic head when at full speed.

At 80%, the operating point should be about 40 GPM @ 34' of dynamic head. So well above 20 GPM threshold. I suspect the issue might be that the HP pressure sensor is not adjusted properly to allow for lower flow rates.

Overall though, the head loss is very high but consistent with 1.5" plumbing and a heat pump. One of the downsides of a heat pump.

Is the HP pressure sensor something that can be fixed diy or would that need to be through the manufacturer?

 

[1poolman1]

Is the HP pressure sensor something that can be fixed diy or would that need to be through the manufacturer?

https://www.aquacomfort.com/wp-content/uploads/2015/03/XL-Series-Service-Manual.pdf

 

[mas985]

This one may have a little better description:

https://www.aquacomfort.com/wp-content/uploads/2015/03/Vintage-Signature-Service-Guide.pdf

 

[CausticMeasures]

This one may have a little better description:

https://www.aquacomfort.com/wp-content/uploads/2015/03/Vintage-Signature-Service-Guide.pdf

Thanks! So my priority is to add a flow meter between filter and heater. If the GPM is too low, check for issue in suction line? We do get a good amount of air bubbles out the returns when the pump is running at lower speeds. Could an air leak at the pump cause the gpm to drop as well?

…If GPM is sufficient, attempt to adjust flow switch. Also here’s the current equipment pad if it helps.

 

[mas985]

Thanks! So my priority is to add a flow meter between filter and heater.

Flow rate through a plumbing system like yours is the same right before the pump, after the pump, before the filter, after the filter, before the heater or after the heater. It doesn't matter. However, it is best to put it anywhere after the filter so debris does not affect the measurement.

If the GPM is too low, check for issue in suction line? We do get a good amount of air bubbles out the returns when the pump is running at lower speeds. Could an air leak at the pump cause the gpm to drop as well?

If the air leak was large enough to cause a large change in flow rate, the pump would lose prime. Small amounts of air do not change the flow rate much. It is proportional to volume. However, if you see air out of the returns, I would start looking for an air leak as that could cause issues as it increases. If it is coming from the suction side of the pump, then you should see air in the pump basket as well.

…If GPM is sufficient, attempt to adjust flow switch. Also here’s the current equipment pad if it helps.

If it were me, I would adjust the pressure switch as it is now. I am fairly confident in the calculations I did for flow rate but you can do what makes you feel more comfortable. Since the flow rate is ~40 GPM now @ 80%, if you can set the RPM to 50%, the flow rate should be around 25 GPM which is above the lower limit. You can then adjust the flow switch so that the heater no longer reads low flow.

Besides the heater, multi-port valves also have quite a bit of head loss which is not helping the situation.

 

[mas985]

Correction. The flow rate is 40 GPM @ 80% so going to 50% should be 25 GPM.

 

[CausticMeasures]

Correction. The flow rate is 40 GPM @ 80% so going to 50% should be 25 GPM.

Circling back now that we opened the pool yesterday. We had the pool liner replaced and I added a flow meter after the filter. 80% pump speed gets 45 gpm. We also had the return and suction lines pressure tested and thankfully there were no leaks. The majority of the buried pool plumbing is believed to be 1.5” black poly irrigation pipe. I know that’s not ideal but hopefully that doesn’t change anything regarding the head loss?

My plan is to adjust the heat pump flow switch as was previously recommended. Unfortunately the linked manuals are no longer functional. Does anyone have access to the aquacomfort 1250 service manual?