Dry heater tried several things…

[Jason Kichline]

Hi, thanks for reading my question. I have a dr wellness spa with 2 pumps. Pump1 has the heater in-line with the filter. If I run the pump, the heater will kick on and continue running normally for several hours. But then eventually the heater gets dry and stops working. I’ve done a lot of googling which taught me to change the filter and burp the air which seem to fix it for several hours (as I said). I also saw how debris can get in the pipe screens and cause restrictions. So I checked the pipes that go in to the pump and heater and it was clean but also I didn’t see any screens. I even replaced gaskets because I found a slow leak during the process. So I removed the filter completely just to try something new and I still have the problem. I’ve been fighting this for about two months and need to run the pumps at least once a day to keep the water hot. Any ideas what else I should be checking? I’m not sure what to check next.

[CanadianSpaTech]

When you turn on the breaker and wait past the PR (priming mode) does the pump 1 eventually start on it's own and run in low speed? Does the heat indicator on the topside then flicker for a minute and then go solid? Post photos of the circuit board, the topside and the schematic on the inside cover of the pack so we can see what control system you have installed.

[Jason Kichline]

Thanks for quick response! I’m pretty sure the heater just flickers and does not go solid but I’ll confirm this weekend. And yes, pump 1 will start on its own at low speed after the priming cycle. The heater will also flicker when heating is needed. I’m not sure how long it takes for things to stop working but it’s definitely less than 1 day. I’ll also get some pics and post. 

[Jason Kichline]

I just realized I do have a couple pics attached here. Pump is WUA400-II. Controller is EnergySaver LPI501ST part number 56882

 

Edited December 14, 2023 by Jason Kichline
Picture upload

[Jason Kichline]

I was able to verify that the heat indicator will turn solid after a minute or two of flashing. I manually started it last night (by running pump at high speed) and it heated right up. It is still maintaining temperature now (>12 hours later) and the pump will start on its own (at low speed) when it needs heat. The schematic (attached below) indicates there are two temperature sensors and you can see them in the heater in the pic. They go to J16 and J17 on the board with small black molex connectors on the right hand side of the board but (can't see it in the pic because all the other wires are in the way). I wiggled and pulled on them (lightly) and they seem to be inserted properly. The pump actually kicked itself on while I was checking it out (before I touched anything). Just odd to me that the whole system seems to run fine for a while. I just wonder if the pump running at low speed is somehow slowly creating an air pocket within the pump. I can't imagine how unless there was some sort of intake restriction. I don't think I have any leaks since the wood frame underneath is dry and the water level doesn't seem to be dropping. I did repair a very minor leak at the output of the heater last weekend but that didn't help the problem. Like I said above, the problem happens even without any filter installed. Just yesterday, I installed a brand new one. My old filters have been cleaned several times over the past 2-3 years so I figured it was time for new ones.

When the display is telling me I have a dry pump, I assumed that is somehow managed with the two thermocouples in the heater. But I really don't know how the circuit determines "dry" vs. "low temp". Maybe if there is a large difference between the two sensors? If that's the case, is it possible one of the two thermocouples is faulty or intermittently dropping out? I will say that when I get the "dry heater" message, I still get a temperature reading but it's just low because it isn't running.

I noticed there is a switch that would add high speed on pump 1 with heat (switch #2). Do you think that is something to try? If it worked, it would probably just be a bandaid to the actual problem.

I am comfortable with electronics but don't have much experience with control circuits. If there are voltages or resistances that I should be checking, I have no problem with that. I'm open to any ideas/suggestions.

Edited December 16, 2023 by Jason Kichline
Had an additional thought about the HS pump 1 option

[CanadianSpaTech]

4 hours ago, Jason Kichline said:

I noticed there is a switch that would add high speed on pump 1 with heat (switch #2).

This means you can run 1 pump on high speed and the heater at the same time. When you engage the second pump the heater will cut out. So.. you can run pump 1 on low and pump 2 on high but when you engage pump 1 into high the heater will turn off. This is due to breaker size. If you have a 50amp GFCI then this is the set up you need if you have a 60amp GFCI you can set it to run both pumps AND the heater on high. I am always surprised when I see the 60 amp not being used but often main panel restrictions come into play.

 

4 hours ago, Jason Kichline said:

My old filters have been cleaned several times over the past 2-3 years

Filters need to be cleaned weekly/biweekly at most. Dirty filters will slow the flow of water and cause flow errors. Any time you have issue with the spa remove the filters and run without until issue if fixed. Take them out of the equation. Just make sure there is nothing in the spa that can go down the hole.

4 hours ago, Jason Kichline said:

I assumed that is somehow managed with the two thermocouples in the heater. But I really don't know how the circuit determines "dry" vs. "low temp". Maybe if there is a large difference between the two sensors? If that's the case, is it possible one of the two thermocouples is faulty or intermittently dropping out?

The sensors test or poll the temp coming into the heater tube and going out of the heater tube. If there is a variance it will send an error msg. 

4 hours ago, Jason Kichline said:

I was able to verify that the heat indicator will turn solid after a minute or two of flashing. I manually started it last night (by running pump at high speed) and it heated right up. It is still maintaining temperature now (>12 hours later) and the pump will start on its own (at low speed) when it needs heat.

So it's working as it should now?

4 hours ago, Jason Kichline said:

I just wonder if the pump running at low speed is somehow slowly creating an air pocket within the pump.

unlikely

4 hours ago, Jason Kichline said:

When the display is telling me I have a dry pump

It's telling you have a DRY heater not pump. Water is not moving across the sensors at each end of the heater tube.

 

5 hours ago, Jason Kichline said:

"low temp"

 

5 hours ago, Jason Kichline said:

I still get a temperature reading but it's just low because it isn't running.

 What do you mean low?... the temp is showing a lower temp reading below what the actual water temp is?

[Jason Kichline]

1 hour ago, CanadianSpaTech said:

I am always surprised when I see the 60 amp not being used but often main panel restrictions come into play.

I wasn't aware of that. I never even thought of it. When I bought the spa, they said it was a 50Amp system so that's what I installed. It would have been harder to install 60 Amps but I would have if I needed.

My spa (even with a 50Amp breaker) will run both pumps at high speed with the heater on. I just double checked that now.

1 hour ago, CanadianSpaTech said:

Filters need to be cleaned weekly/biweekly at most.

I don't disagree but it's difficult to keep up with that schedule. I usually do it once a month or so.  I did run without filter for a few days but the problem never went away. We also don't use it very often. Once a week at most.

 

1 hour ago, CanadianSpaTech said:

The sensors test or poll the temp coming into the heater tube and going out of the heater tube. If there is a variance it will send an error msg. 

Makes sense. Is this the "dry heater" error or something different? I just went out to check it and got a "heater flow fail" error. I haven't seen that before. So I turned the pump on high then back down to low and the heater flickered for a while then check to solid. The temp dropped to 97 while it wasn't working. Only difference is I just installed a new filter.

1 hour ago, CanadianSpaTech said:

So it's working as it should now?

Only for a while as noted above.

 

1 hour ago, CanadianSpaTech said:

It's telling you have a DRY heater not pump. Water is not moving across the sensors at each end of the heater tube.

agreed. I meant "dry heater" but accidently wrote "dry pump"

1 hour ago, CanadianSpaTech said:

What do you mean low?... the temp is showing a lower temp reading below what the actual water temp is?

I think the answer is yes but not 100% sure. There have been times when it reads 65 degrees but the water feels much warmer than that. Then when running the pump, the reading rises quickly. I thought if there was air in the heater tube, the temperature reading was sensing air temp. Then, when I turn the pump on, the thermocouple senses the warm water and the reading rises quickly. However, I think I remember a time or two where I didn't see any temperature at all. But didn't pay close enough attention back then.

[CanadianSpaTech]

Things I might try...

Check the face of the pump for debris. Disconnect the union at the face of the pump and check for anything that could be blocking the flow of water. I often see the spring loaded "flapper" that sits at the bottom of the filter basket break away and end up at the face of the pump blocking flow... or further down the line and it gets into the heater tube and lodged up against the heater element or sensor and that is the next place I would look... remove the heater tube and check for debris in the tube like the flapper or other material that can affect the operation of the sensors.

 

 

[Jason Kichline]

14 minutes ago, CanadianSpaTech said:

Things I might try...

Check the face of the pump for debris. Disconnect the union at the face of the pump and check for anything that could be blocking the flow of water. I often see the spring loaded "flapper" that sits at the bottom of the filter basket break away and end up at the face of the pump blocking flow... or further down the line and it gets into the heater tube and lodged up against the heater element or sensor and that is the next place I would look... remove the heater tube and check for debris in the tube like the flapper or other material that can affect the operation of the sensors.

 

 

Thanks again for helping! That's a good thought. I've already checked the intake to pump 1, the pipe from the pump to the heater, and the heater tube and all are really clean. I didn't realize there was a spring loaded flapper at the bottom of the filter. I thought that maybe I should snake that pipe out just to double check. I guess something like that could be stuck in the middle. I think I'll try that next. We're getting tons of rain today so I won't have a chance to look at that until next weekend. Do you know why there is a flapper?

[CanadianSpaTech]

1 hour ago, Jason Kichline said:

Do you know why there is a flapper?

When the spa is running on low for filtering/heating the spring loaded flapper is closed so the water is pulled down through the filter from the top. When you engage high speed the pump needs extra water to feed the pump so the flapper opens and the extra needed water gets pulled from the suction returns in the foot well.

Some spas might have a one way check valve installed in the plumbing to essentially do the same job with the spring loaded flapper in the valve. 

[CanadianSpaTech]

One Way check valve...

 

Flapper at bottom of filter basket... If your has one you should be able to see it with the filter removed...

 

Watch this video: https://www.youtube.com/watch?v=BUaTiSMfKDU

 

[Jason Kichline]

So I got out there before the rain got too crazy. I removed the filter and could see the flapper you mentioned. It looks like it’s in good shape. But you got me thinking about the footwell intakes. I have three and they all had a small amount of debris in them. So I took them off, clean them up and put them back in. I’m running again now without the filter out. Well

[Jason Kichline]

So cleaning the footwell screens didn’t help either. I’m running without main filter and still have the same problem. I guess the only thing left to do is snake the pipes. After that, I’m out of ideas

[Spa Board Doctor]

Hello,

It seems like maybe the low pump may be dropping out sometimes.  You should set the filtration timer to continuous operation i.e. 24 hour circulation and see if the problem goes away.

Brandon

[stanconnie]

Does the Intertek 3168033 WUA400-ii motor have only a run 40 uf capacitor?

[Jason Kichline]

I set to 24 hour filter time last night. It was still running this morning and seems ok. Not sure about how to find out about pump capacitor other than what it says on the sticker. Is that a replaceable item? Is that under the large cover on top of the pump?

some additional info… about a year ago, the impeller on that pump cut a hole in the manifold so I replaced it. I don’t think it’s related but who knows. I didn’t have any issues until several months after that.

[Spa Board Doctor]

Hi,

Keep it in continuous operation until you are satisfied that the problem has been resolved. 
My recommendation would be to replace the pump with an AquaFlo XP2 or Waterway EX2 pump with the same voltage and amperage as the original (230V 12.0/4.4A) as the LX pumps are, IMO, junky junk.

brandon@spaboarddoctor.com

[Jason Kichline]

Gotcha. So far continuous operation is working for the past 24 hours. I’ll keep monitoring. I hate to replace the pump unless I’m sure it’ll fix the problem. Hard to tell exactly what’s happening without watching it 24/7. Looks like the pump you recommended is roughly $250-$300. 

[Jason Kichline]

So the pump has been running fine since I set it to continuous Tuesday night (3 nights ago). Does mean there’s a problem with the pump in general or just problem with the pump starting. Seems like maybe a weak starting capacitor would cause that kind of a problem. What do you think?

[stanconnie]

I have the same system with the same problem. The pump will not start in low speed but will start in high speed and will run in low speed till the set temperature is reached. I replaced the 40 uf capacitor with a 45 uf capacitor and got some better results ( see pictures below)

Before capacitor change:                                                After capacitor change:

 

[Jason Kichline]

16 hours ago, stanconnie said:

I replaced the 40 uf capacitor with a 45 uf capacitor                               

That’s great data! I assume the 45uf fit just fine and it’s rated for the same voltage? I will replace my capacitor and see what happens. What do you use to monitor temperature? I definitely want to get something like that

[stanconnie]

 

 

The 45uf capacitor from Amazon I used is:

VEXUNGA 45uF 45 MFD 370VAC 440VAC 450VAC 50/60Hz CBB65 CBB65B Run Start Capacitor for AC Unit Fan Motor Start or Pool Pump or Air Condenser Straight Cool

The floating temperature and WIFI system I use from Amazon is:

INKBIRD 2nd-Gen Floating Pool Thermometer Digital with IBS-M2 Wi-Fi Gateway Combo, Wireless Swimming Pool Thermometer Set, Easy Reading, Digital Pool Thermometer for Swimming Pools

Please be aware that this only fixed the problem some of the time!

[Jason Kichline]

7 hours ago, stanconnie said:

Please be aware that this only fixed the problem some of the time!

Thanks for the info! I ordered the cap and a different temp monitor. Hopefully it helps. So what do you mean it’s only fixed some of the time? Does the motor still fail to start?

[stanconnie]

As you can tell from the second picture, the pump failed after several cycles when it tried to start to bring the temperature up to the set value!

[Jason Kichline]

15 hours ago, stanconnie said:

As you can tell from the second picture, the pump failed after several cycles when it tried to start to bring the temperature up to the set value!

Ah. Interesting. I didn’t notice the failure until you brought it to my attention. Now that I look closer, it’s weird how (when it failed) the temperature drops slower than the other cycles. I’m not sure if that means anything or not. Is your pump still failing to start or is the heater not coming on (or both)? Have you been able to figure out the root cause of the problem? Did you remove the filter for your troubleshooting?

I got my capacitor last night. I’ll put it in today. My temperature monitor isn’t expected to arrive until Jan 3 even after amazon showed 2-day delivery when I bought it.