Omnilogic and "Freeze Protection" are going to destroy my new pool

[zerocylinders]

We just had a small plunge pool (9x15x4) built in ground. Yes it is freezing cold outside, but we had to finish the pool to be able to install pavers in spring. Anyway, we have Hayward equipment - Omnilogic panel, 100K BTU gas heat, and 2 speed pump. We also have 3x5hp swim jet pumps and 3x strip drains, one skimmer. Pool builder went on vacation after he thought all was working, but of course it isn't working and I am convinced there is a configuration issue with "freeze protection" that is going to kill our new pool. Any help or ideas greatly appreciated.

Before our pool builder left, I noticed that the pool, normally set at 85 degrees, was dropping overnight a couple of degrees every few hours (even with the cover on). The builder came out did some tests, called Hayward, and they decided the problem was the swim jets and lack of sufficient back pressure due to the large diameter pipes in the swim jet system (6" PVC). So he winterized the swim jets and closed them off, then also reduced the pressure switch on the heater so it would not require so much back pressure to activate. That was Dec 23 and he is now on vacation.

Meanwhile, even with swim jets shut off, we have the same problem. Except I noticed the pattern - the temperature starts dropping as soon as freeze protection turns on. Turn off freeze protection (manually at the panel, then restart pump of course) and the heater immediately comes back on.

So to summarize:
Freeze protection on = heater off, pump on
Freeze protection off, restart pump = heater on

Looks like weather here in Chicago will stay in the freeze zone for next week so this is an issue (especially if it drops below 10 pipes can freeze very quickly).

I would be inclined to just disable freeze protection, keep heater and pump running non-stop until weather warms up above 32. However, I can only disable freeze protection for 180 minutes max on the panel - I need to get into programming mode - if there is such a thing - to fix the internal programming on freeze protection. Currently, I am disabling freeze protection once per day, letting heat stay off overnight, and then restarting everything in morning (disabling freeze protection) to get pool back up to temp.. then it drops back overnight on freeze protection.

Would like to figure this out and fix it, but I am not familiar with Hayward equipment at all so appreciate any insights and guidance here. Specific guidance on programming the controller would be helpful or at least viewing the programming would be great - the panel user GUI really is limited I need something like an expert mode if one exists where I can access from my computer and rewrite the freeze protection script- that would be ideal. In any case, I do NOT think it is the pressure switch on the heater, because merely disabling freeze protection will instantly restart the heater. If it was the pressure switch, that woudn't work.

Possible issues/fixes I can think of (but no idea how to fix):

1 - Possibly the freeze protection is setting pump to LOW, which does not generate enough pressure to turn heater on; then when I restart pump it goes to high? I think the pump is two speed, but not sure (the swim jet pumps are two speed, but the filter pump is separate so I am not sure).

2 - Temporary fix - I need a way to disable freeze protection long term at least 1 week, but how?

3 - Ideally, would want to program freeze protection to turn on ONLY IF the pump is not already running. That would solve 90% of this problem.

4- If the issue is not #1, then the Omnilogic must be actually turning off the heater on freeze protection. It should not do this, but how can I view the programming/logic to see if this is an intentional decision and if so, how to modify the logic?

Best regards and thanks to everyone!

Jeff

 

[kimkats]

Hi and welcome to TFP! Most people in you neck of the woods close their pools to keep them and the pipes safe.

Your electric/oil/gas bill is going to be out of this world if you try to keep the pool heated all winter. May not be a problem for your wallet but man it would hurt mine.

As far as how to keep the pump and heater running I am not sure how to do that. This post should get more eyes on your thread.

Let us know what you end up doing.

 

[JJ_Tex]

We have different automation systems, but mine will let you select what will be included in the freeze protection. You just go to each circuit/piece of equipment and there is a check box for freeze protection.

Does your have something similar where you could include your heater in freeze protection? Alternatively you could make your "pool" circuit associated with the heater as well.

Hopefully someone familiar with the Omnilogic will chime in. In the meantime, I would play around with what I mentioned above, and also fill out your signature with your equipment so we know what exactly we are dealing with.

 

[zerocylinders]

Thanks Kimkats! The cold weather is why we built such a small pool. Many folks keep their hot tubs heated through the winter, so this is really just a big hot tub in terms of size ~ 4000 gallons. We designed the small "plunge" pool so we could keep it open in the winter .. In ground, so it is easier to keep heated without spending a ton of money on gas and electric versus a hot tub; a mostly sealed automatic cover to deal with evaporation; and the heater is natural gas 100,000 BTU which is oversized for the pool. We had a larger (50,000 gallon) pool at our old house with no cover and a 20 year old gas heater, and we kept that running all winter one time - the gas bill for that was around 1400 per month which was expensive (but keeping open partially offset by not having to pay an average of $4,000 to open / close the old pool, which needed heavy maintenance each year after opening due to freeze/thaw cracks). In any event, I am betting that with the cover, a more efficient heater, and smaller pool, our gas bill should should be no more than 300 or so extra. Will track and let you know.

Still trying to solve the heating / freeze protection issue. I found another post in another thread that mentioned that the web version of Omnitrack has more features versus the App. I can confirm that - through the web (unlike the app) I can turn off freeze protection from my computer (but only for 3 hours). So at least I don't have to run outside now. That is progress!

 

[kimkats]

Make sure to look at @JJ_Tex post above your last one.

Sounds like you are making progress...........keep playing with it WHILE taking notes to help your remember what you did and what it did in response.

Big hot tub-got it! You planned ahead with the cover and everything. WELL DONE!

Kim

 

[zerocylinders]

@JJ_Tex - there is no option I can find to selectively enable or disable freeze protection. It is possible that you can do so in the setup wizard, which is locked with an installer password. I may try to hack into that if I get desperate.. I bet my builder just used the default password but i haven't tried that yet.

I added my equipment in my signature.

 

[ajw22]

It is possible that you can do so in the setup wizard, which is locked with an installer password.

That is your problem. Freeze protection is enabled or disabled individually for each device. There is no permanent master on/off for freeze protection.

See https://hayward-pool-assets.com/assets/documents/pools/pdf/manuals/omnilogic-hlbase-install.pdf page 26 & 30 & 31& 33 & 36 & 39-42 in Configuration Wizard to enable or disable Freeze Protection for various devices.

Also https://hayward-pool-assets.com/assets/documents/pools/pdf/manuals/omnilogic-hlbase-operation.pdf

See page 19

In the Hayward heater manuals https://www.hayward-pool.com/assets...uals/UHS-Service-Installation-011717-RevT.pdf and https://www.hayward-pool.com/assets/documents/pools/pdf/manuals/UHS-OwnersManual011717-RevJ.pdf there are multiple warnings not to use the heater for freeze protection. The OmniLogic is enforcing that when it goes into freeze protection mode...

Winterization :
In moderate climates, the heater can continue to operate during short-term cold spells. Do not use the heater to maintain the water temperature just above freezing or for freeze protection. Care must be taken to avoid freeze-up in the heater. When it is used during freezing weather, the pump must run continuously. The heater is not warranted against freeze-ups. In regions where freezing temperatures are encountered, all water must be drained from the heater when it is out of service, to prevent damage to the heater and piping. Draining the heat exchanger is recommended as part of the season’s shutdown procedures.

 

[kimkats]

Fiberglass + EcoFinish??????? I know this is off topic for this thread but I want to hear about this way of finishing a pool.

 

[zerocylinders]

@ajw22 thank you! We are using the pool all winter hot tub "Nordic" style so the warning doesn't really apply. We are keeping the temp at 85 degrees all winter, and the pump is running continuously (in warmer weather, I will use the schedule to turn the pump off during the day). I think what you cited though confirms my intuition, that freeze protection should just be turned off entirely when the pump is kept running and the heater kept on. Since the heater is supposed to be running all the time, the fact that freeze protection turns the heather OFF is endangering the heater itself. That it exactly my concern, as water must be flowing through the heater non-stop. By turning off the heater, freeze protection is endangering my year round hot tub pool! I am hoping that there is not already damage.

@kimkats My understanding is that ecofinish was originally developed for fiberglass pools. We used it to repair our last pool that was > 20 years old. For our old pool, the builder ripped out the old fiberglass panels that were irreparably damaged from cracks and bad seams, and put in all new fiberglass, then finished with ecofinish. It was basically a new pool at that point (he also redid the plumbing and concrete deck).

For our new pool, we decided to stick with fiberglass mostly for cost reasons. Our builder hand lays the fiberglass over wood as a frame, then adds the EcoFinish. He was able to work in 30-40 degree weather using a tent and propane heater (and flame thrower for the EcoFinish). I am sure that poured concrete would be a superior choice for a complex shaped pool, but our simple rectangular fiberglass pool was about 1/4 cost versus what we were quoted for a "simple" concrete pool. So even if this pool lasts only 5-10 years .. still cheaper! And we fan always relay the fiberglass as we did with our 20 year old pool in the last house if problems develop over time. Of course most hot tubs are fiberglass so thinking of this as a big Hot Tub it seemed like the right choice. Ask me in a few years though!

 

[ajw22]

We are using the pool all winter hot tub "Nordic" style so the warning doesn't really apply.

Do you know if Hayward has tested and rated your heater for "Nordic operations"?

There is more then just keeping the water flowing to prevent freeze damage in the heater in a prolonged deep freeze. Condensation lines can freeze and clog, sensors can freeze, moisture can form internally in the heater and freeze.

Keep an eye on your heater if you get any Chicago deep freezes in the coming winters. I believe you are using your heater in ways Hayward did not intend.

Do you have a Plan B if your heater and/or power fails during a deep freeze?

Preparing Pool for Cooler Months - Further Reading

www.troublefreepool.com

 

[JoyfulNoise]

Even with a small volume of 4,000 gallons (~ 32,000 lbs of water), a 150kBTU/hr heater operating at 80% efficiency (that's about what you can expect from nat gas and it gets worse when it's cold), is only going to get you about 3.6F temperature rise per hour. In the depths of a Chicago winter, you are going to easily lose 6-8F overnight (and I suspect it's a lot higher). Autocovers are very thin and they sit in direct contact with the water because you need the buoyancy to help support the cover weight. That direct contact means the cover is simply going to transfer the heat out of the water and into the air. It's better than no cover at all but you are battling against freezing air temperatures, and it's battle that a small gas heater is not going to win.

Yes, the pool is in-ground, but in the Chicago area, the frost line can be as deep as 40". That means most of the shell of the pool, unless it was built with insulation, is in direct contact with essentially frozen earth (32F). All of the piping is in contact with freezing ground too. Unless the builder used thermally insulated PVC (yes, it does exist), then all of the pipes are radiating heat into the ground. Finally, unless the equipment is in a heated shed, or even just a covered shed, the above ground equipment itself is going radiate heat away too. All of these heat losses add up and overwhelm the heater's ability to keep the water warm.

Finally, as @ajw22 has noted, your heater is NOT designed to work out in freezing temperatures. The incoming air from the inducer motor (the blower) is below freezing. It mixes with natural gas and at that temperature combustion will be incomplete at best. Incomplete combustion can lead to soot forming in the heat exchanger. Also, condensation of flue gases at low temperatures can create a very acidic condensate which can cause all kinds of problems if it is not properly drained.

I know you really want to have a "nordic experience" but I don't think your plunge pool is going to survive for long. You can certainly keep the gas heater and pumps running but it's going to cost you a lot of money to do so. Hot tubs are not a good comparison because they are designed to work in cold outdoor environments. They have hard covers that are thick and insulated and do not contact the water. The internal parts of the hot tub are often sprayed with foam insulation to keep the heat in. And, of course, a hot tub is 1/10th the volume of water you are trying to heat. Even under those conditions, a hot tub running out in the open in freezing air temps will lose more heat from evaporation than the tiny heater can supply and so people rarely spend a lot of time sitting in a hot tub when the air is freezing.

Not trying to be a naysayer and I wish you luck in getting this all sorted out, but fighting against mother nature rarely results in a win....

 

[ajw22]

Finally, as @ajw22 has noted, your heater is NOT designed to work out in freezing temperatures. The incoming air from the inducer motor (the blower) is below freezing. It mixes with natural gas and at that temperature combustion will be incomplete at best. Incomplete combustion can lead to soot forming in the heat exchanger. Also, condensation of flue gases at low temperatures can create a very acidic condensate which can cause all kinds of problems if it is not properly drained.

Heater Condensation - Further Reading

www.troublefreepool.com

 

[kimkats]

Thank you for telling me how they did it! I bet it last a good, long time! Now go have a long soak for me in your warm pool!

 

[zerocylinders]

Thanks for all the info. Have some things to think about. I was already concerned about the cover, but my builder assured me it would insulate as well as an insulated hard cover. We will see, but if it doesn't insulate well I can always add a spa type folding hard cover over the top. At the least, the massive loss due to evaporative cooling is avoided with the automatic cover, and I can tell you from experience with an uncovered pool in winter that evaporative cooling is much much more serious than direct contact cooling.

@ajw22 I looked at the manual, not much information there. Part of the manual (quoted above) says that in freezing temps the pumps and heater must be run continuously, which is what I planned to do anyway. But there is the warning that there is no warranty for freezing so that is concerning to me. This is the heater my builder recommended and he has several pools open all winter. What heater would you recommend that is rated for freezing temps? If there is a better choice, I might be able to get the builder to swap out.

@JoyfulNoise The volume of our "pool" is exactly equal to the hot tub spa we were considering purchasing, so I think it is a valid comparison. Although the frost line sometimes goes that deep, it is rare in Chicago to have frozen earth deeper than 24" (lake effect warming keeps area near lake a few degrees higher in winter so usually only the top 1-2 feet is frozen). Even so, at 32 degrees earth is still a much better insulator than air at 0 degrees. Plus, since the pool is kept at 85 the ground around the pool will not be at 32 degrees. The heat radiated from the pool walls will be kept in the surrounding earth, which holds heat pretty well. There are a lot of in ground pools around here that stay open all winter (at the cost of heating gas and electricity). I ran my older in ground pool all winter with no issues other than a big heating bill, and that was with a 20+ year old gas heater. Plenty of above ground spas run all winter here as well. This cannot be rocket science, though I am concerned about the Hayward system my builder chose as I am not sure it is up to the task at all.

As far as backup plans, we have a 100A generac with automatic cut on so electricity should not be an issue. If the heater fails, the backup would be to drain the system as quickly as possible. As long as the pump can run, it will take a long time for the pipes to freeze though the heater would probably be destroyed if it stopped working and froze. If the pump fails too, that would be really bad. I might think about a backup to that, but I am not sure if a backup would even help - if the pump dies by the time I swapped in a new pump the lines would probably be frozen above ground. What would you recommend?

 

[ajw22]

Hayward says:

Winterization :
In moderate climates, the heater can continue to operate during short-term cold spells. Do not use the heater to maintain the water temperature just above freezing or for freeze protection. Care must be taken to avoid freeze-up in the heater. When it is used during freezing weather, the pump must run continuously. The heater is not warranted against freeze-ups. In regions where freezing temperatures are encountered, all water must be drained from the heater when it is out of service, to prevent damage to the heater and piping. Draining the heat exchanger is recommended as part of the season’s shutdown procedures.

Part of the manual (quoted above) says that in freezing temps the pumps and heater must be run continuously, which is what I planned to do anyway. But there is the warning that there is no warranty for freezing so that is concerning to me.

No where does its say that in freezing temps the heater must be run continuously.

I agree it is poorly worded. I think "When it is used during freezing weather, the pump must run continuously." used refers to the pool being open and water flowing through the heater, not that the heater is on and generating heat.

This is the heater my builder recommended and he has several pools open all winter.

Do you know if these pools and heaters work the way you expect yours too? They could all be problematic. And a lot of this depends on the vagaries of winter weather.

What heater would you recommend that is rated for freezing temps? If there is a better choice, I might be able to get the builder to swap out.

I have not seen a gas pool heater that the manufacturer rates for outdoor freezing use. I think if you look at resort heated pools in snow country the heater and pool equipment is indoors in some type of heated enclosure so the equipment including the heater is not ever in freezing air temperatures.

The volume of our "pool" is exactly equal to the hot tub spa we were considering purchasing, so I think it is a valid comparison.

Hot tub spas use various forms of electrical heat that do not have the issues that gas heaters do of operating in freezing air temperatures. And a lot of insulation to retain heat all around.

For what I understand your desires are I would have recommended a larger 400K BTU gas heater or even 500K BTU heater with equipment in a heated equipment shed. At this point all you can do is see how well your setup works. Maybe global warming will help you with mild winters. Or you be resigned to going through heaters every few years. And if heating your pool get too problematic then winterize it for 2 or 3 months in the winter.