Heating Issue

[Mbad]

I have a 2009 Arctic Spa hot tub and I’m having hard time getting it to heat to 104°.  I’ve had several issues over the winter which caused replacement of the pump with impeller, heater, cover and pressure switch.  On low the heater  kicks in (amps are 23 and volts at 240) but the problem is the tub never really heats past 100°. If I turn the pump on high and continually turn it back to high I can get it to 104° but settles back down around 100. This causes the pump the run continuously on low because the temp set point is never reached.  I had tested the temp probe and high limit probe for resistance and both were closing to normal readings. The only thing I know is broken is the bypass valve in the bottom of the filter canister. Could this being broken cause low enough circulation that the tub doesn’t adequately heat on low?

edit: also no error codes 

[RDspaguy]

5 hours ago, Mbad said:

I had tested the temp probe and high limit probe for resistance and both were closing to normal readings.

How close? What readings?

5 hours ago, Mbad said:

Could this being broken cause low enough circulation that the tub doesn’t adequately heat on low?

Yes, but it wouldn't work at lower temps and stop magically at 100*.

Post a pic of the circuit board, wiring diagram, and equipment area.

[Mbad]

42 minutes ago, RDspaguy said:

Yes, but it wouldn't work at lower temps and stop magically at 100*.

You’re right that it didn’t magically stop there but at the southern Ontario temps we’ve been having (-5°C to -10°) that’s about where it was sitting for the last week. If I turned the set point to 99° the heater would shut off and the pump would shut down but turn it back to 100° or above and it would just run continuously and not warm any further unless I put it on high speed. 

 

47 minutes ago, RDspaguy said:

How close? What readings?

The temp probe was 6290 ohms at 97°. 

I’ll get pics of the equipment in the morning  thanks for your reply

 

[RDspaguy]

When testing sensors you must test both and compare the two readings. 

The pump running non-stop will produce some heat. A typical spa heater wired at 240v will increase the temp by 6-8 degrees per hour. The pump by itself will take much longer. Do you have a separate thermometer to verify the actual temp in the tub?

The mystery is that it heats to 100, then stops with no errors. Not heating at all is common and pretty easy to figure out, but heating partway repeatedly is rather odd.

But I haven't seen a spa I couldn't fix yet, so I am confident we'll get there. Maybe not as fast as if I were there...

If it gets too hairy we can always call on @CanadianSpaTech to solve the mystery. He will tell you to "remove your filter until the issue is resolved, just take it out of the equation". Which is excellent advice, especially if the bypass valve is broken. Try that.

Thanks, @CanadianSpaTech. You're my hero! I'm going to be just like you if I ever grow up! 😂

[CanadianSpaTech]

Is the temp probe through the side wall of the spa? If so make sure there is a plug or cover over the back of the probe inside the spa cabinet to prevent the probe from reading incorrect temp.

If that fails remove your filter until the issue is resolved, just take it out of the equation...lol

Where in Ont.?

Did you find the bypass valve flapper or did it get sucked in? 

Another thing I would check is for a plaque build up on the heater element.  Hot tubs in hard water areas, or those that are filled from a well can have trouble with metals and minerals. Lime & calcium can naturally collect on a heater element surface, forming a white coating. This layer of scale will slow heat transfer, resulting in lower efficiency, longer heater run time, and a higher internal element temperature. The plaque buildup will not let heat escape efficiently

[RDspaguy]

46 minutes ago, CanadianSpaTech said:

Did you find the bypass valve flapper or did it get sucked in? 

I assumed the flapper was stuck or found when the pump was replaced. Not sure on the temp correlation though. Why 100*? It should constant or random, not temperature related.

9 hours ago, Mbad said:

I’ve had several issues over the winter which caused replacement of the pump with impeller, heater, cover and pressure switch.

Please describe these issues.

 

58 minutes ago, CanadianSpaTech said:

The plaque buildup will not let heat escape efficiently

Now you're just showing off... 🤣

[Mbad]

8 hours ago, RDspaguy said:

When testing sensors you must test both and compare the two readings. 

This I didn't do.  The temp probe is spray foamed into the shell and didn't want to remove it yet to compare the 2 in the same air temp.  My meter died before getting a chance to test the high temp probe so I didn't get a reading off of that.  You'll cringe at this but I hung the high temp probe out of the cabinet and ran the tub to see if that was some how cutting off the heater with no error code, didn't help.

 

8 hours ago, RDspaguy said:

Do you have a separate thermometer to verify the actual temp in the tub?

I did, it was about a degree difference

[Mbad]

7 hours ago, CanadianSpaTech said:

Is the temp probe through the side wall of the spa? If so make sure there is a plug or cover over the back of the probe inside the spa cabinet to prevent the probe from reading incorrect temp

It is spray foamed in and I haven't taken it out to inspect but at this point I'm assuming it hasn't moved

 

7 hours ago, CanadianSpaTech said:

If that fails remove your filter until the issue is resolved, just take it out of the equation...lol

I've had the filter out for the last 2 weeks...no change

 

7 hours ago, CanadianSpaTech said:

Did you find the bypass valve flapper or did it get sucked in? 

Oh yeah that was found in the impeller on the old pump, nothing to worry about now

 

7 hours ago, CanadianSpaTech said:

Another thing I would check is for a plaque build up on the heater element

The new heater element was installed on January 17th as the old one was causing a short tripping the GFCI,  Water was leaking by a post in the heater tube.

 

7 hours ago, CanadianSpaTech said:

Where in Ont.

Whitby

[CanadianSpaTech]

Whitby! (spits on ground) sorry to hear that...lol I am West of Milton so way out of my area.

I would be trying a new set of sensors next. Always sucks to throw parts at a problem but...

If you can find something to plug the hole where the temp probe goes through the side wall of the spa and pull out the sensor and see if anything changes. Might have to drain the water down below the sensor to remove it and plug the opening then top it up again.

You could give Gecko a call directly and see if they have encountered this odd set of circumstances 1 800 784 3256 they are usually very helpful. Assuming its a Gecko pack.

[RDspaguy]

2 hours ago, Mbad said:

The temp probe is spray foamed into the shell and didn't want to remove it yet to compare the 2 in the same air temp. 

The point is to test them where they are. Turn temp down and run pump for a minute to clear any residual heat and test. This is assuming it is not a gecko pack. 

2 hours ago, Mbad said:

but I hung the high temp probe out of the cabinet

Ok. Not a gecko.

 

[Mbad]

31 minutes ago, CanadianSpaTech said:

Whitby! (spits on ground) sorry to hear that...lol I am West of Milton so way out of my area.

I would be trying a new set of sensors next. Always sucks to throw parts at a problem but...

If you can find something to plug the hole where the temp probe goes through the side wall of the spa and pull out the sensor and see if anything changes. Might have to drain the water down below the sensor to remove it and plug the opening then top it up again.

You could give Gecko a call directly and see if they have encountered this odd set of circumstances 1 800 784 3256 they are usually very helpful. Assuming its a Gecko pack.

A new set of sensors is tough to swallow on a hope but I think that's my next step.  I appreciate your advice.  I never thought to actually call the manufacturer, good call.  Thanks!

[Mbad]

10 minutes ago, RDspaguy said:

The point is to test them where they are. Turn temp down and run pump for a minute to clear any residual heat and test. This is assuming it is not a gecko pack. 

Ok. Not a gecko.

 

I will try that out today then with them in place.  I didn't know if it would alter things enough with the high temp sensor compressed on the heater tube and the temp probe actually in the water.

And yes it us a gecko M class.  The heater tube is not in the spa pack, it is separated and a foot away.  The high temp probe is a 48" cable that travels out of the spa pack and over to the heater in the next access panel.  I left before sunrise today but will get pics when I get home.

[RDspaguy]

3 minutes ago, Mbad said:

I left before sunrise today but will get pics when I get home.

My condolences.

[Mbad]

So I put a Wi-Fi thermometer on the heater tub 36 hours ago when I took the high limit probe out and let it sit outside. For those 12 hours the tub didn’t heat properly. Yesterday around dinner time I shut down the tub to check something and turned it back on. As you can see in the photo it’s worked flawlessly for the last 24 hours. Yesterday in a frustrated state I forgot to put a back access panel back on which is why the peaks are so much lower until this morning when it was put back on. Not feeling like messing with it tonight I placed the high limit probe back on the heater tube. If it messes up again tonight I know it’s the high limit probe. I’ll check the resistance in both sensors tomorrow to confirm.  Man I hope this is it, it’s been a fight for while now. 

[RDspaguy]

4 hours ago, Mbad said:

If it messes up again tonight I know it’s the high limit probe.

Not sure how you came to that conclusion, but I disagree. In fact, if it messes up again it is almost certainly a flow issue.

 

4 hours ago, Mbad said:

Yesterday in a frustrated state I forgot to put a back access panel back on which is why the peaks are so much lower until this morning when it was put back on. No

??? The fact that you had a panel off should not effect the temp that it heats the water up to, just the speed that it gets there and how long it holds. Is your probe in the water or on the outside of the heater?

 

[Mbad]

7 hours ago, RDspaguy said:

Not sure how you came to that conclusion, but I disagree. In fact, if it messes up again it is almost certainly a flow issue.

 

??? The fact that you had a panel off should not effect the temp that it heats the water up to, just the speed that it gets there and how long it holds. Is your probe in the water or on the outside of the heater?

 

Can you explain why you think it’s a flow issue if it fails with the high limit back on the tube?  I’m not doubting just trying to reason this out. I’m just grasping for answers in my own head which haven’t been right so far. 

You are right, having the panel off does not affect how the tub heats. The tub water was still heating to 104 and shutting off. The high limit probe was installed by the factory against the outside wall of the heater tube under a piece of foam. When the access panel is taken off its exposed to outside air which shows a lower value. The Wi-Fi probe that I put in is in the exact same spot so when the panel is off the values are lower but show the on and off of the heater in the previous pic. The tub water was actually still 104 but the reading on the outside of the heater tube was not having outside air exposed to the high limit probe 

i appreciate your patience with me. 

[RDspaguy]

4 hours ago, Mbad said:

Can you explain why you think it’s a flow issue

Mainly because I got my threads mixed up and thought we were talking about a balboa system, which would have errors for a faulty sensor. Not sure on an old gecko how "smart" it really is. As I recall, it should throw an error if shutting off for hi-limit overheat but will not for a sensor discrepancy. 

@CanadianSpaTech, you know these gecko controls better than I. What do you think?

The temp sensor is what sends the reading to the controller and determines when to turn the heater on and off. There is nothing that I can think of that would turn the heater off early and not show an error. Except economy mode. 

[CanadianSpaTech]

My $.02 is already in the pot

[Mbad]

Sensors on order, awaiting delivery. 
 

thanks guys 

[Mbad]

So I installed both the temp sensor and the high limit sensor yesterday and it worked fine for about 9 hours and then things stop working right.  The temp stays where it is and the heater continues to call for heat and the pump never shuts off.  I woke up this morning and power cycled the tub and it shut the pump/heater off for about 5 minutes and then it kicked back in.  Then continue to run never kicking back out.  The saga continues.