mountainguy

Fixed... everything works now. The FL1 was a problem of my own making - when I originally opened the tub a couple of months ago i was so angry with the leaking flow switch that was "professionally" repaired that i tightened it by hand 1/4 turn and screwed the direction of the flapper thingy. I figured this out even before opening the hot tub, I remembered that episode when i went to pick up some plumber tape to redo the switch. The "professionals" had used just a couple of turns of thin tape and it was not working...(random thought - HF has MUCH better tape than HD, it is much thicker). So I removed the flow switch, re-taped it and put it back on, pointing in the correct direction. FL1 is gone, heater working, etc. I will let it run for 48 hrs and then do a deep clean with Ahhsome and replace the water. CanadianSpaTech - I cannot thank you enough for your help and advice... I really appreciate it!

Thank you for the great trouble shooting guidance. I will do that over the weekend. The circ pump seems to be working and I suspect it is the flow switch but will see how it turns out... Thanks!

Partial progress... replaced the terminal block, snubber and the burned wires today and fired it up. The display turned on, both pumps work... Thank you CanadianSpaTech for your help to get me running again! Now, the partial part - I have a FL1 error on the display and the heater does not turn on. All I had time to do was clean the filter, which did not help... will do some more trouble shooting and will try to purge air over the weekend. I only know FL1 is switch stuck open or dirty filter/air pocket so need to research a little more.

perfect, thank you! Ordering now...

Thank you CanadianSpaTech - the thread you referenced seems to be covering the same or very similar problem that I am dealing with... apparently is not an isolated incident. After much delay I finally was able to get to the hot tub this weekend and did some further dismantling/trouble shooting: - Removed and inspected the board - looks fine to me and I did not see any obvious shorts/issues/damage. Pics attached, let me know if you see anything that looks unusual or problematic - Removed the snubber - looks ok visibly but based on testing per YouTube instructions it appears to be blown. I was planning to replace it anyways because it does not pass my smell test - I had a short that melted 10ga wire at the same spot where the snubber was attached... no way in my book it is still good. I will try to source one from the thread in the post above, hopefully they still have 'em. - The wire terminal/connector where the main power line connects to the board is bad due to the short. Not sure if you can see well from the pics below but the terminal is a two piece design with a rivet. I presume when the short occurred, the plastic attachment point on the terminal body melted and allowed the 2 metal pieces to come apart a bit... or it could be that that attachment point was loose and actually caused the short. Anyways, it is bad and need replacing - any ideas if that part is available to purchase or do I need to get a generic terminal piece? - Lastly, I also checked the pump where the flow sensor was dripping - under the cover everything looked fine so it appears the only damage is on the outside. I plan on disconnecting that pump when I first turn on the hot tub after i repair it, just in case. If anyone has a suggestion on sourcing a terminal replacement please let me know - the part number is GP GPT53000021 but my initial search is coming up empty for that number... As always - thank you very much for your help!

Hi folks, just a quick note that i have not forgotten about this thread but was not at the location of the hot tub for a while. I hope to be able to replace the burnt wires this weekend, weather permitting, and will update after that...

nothing that was notable enough to remember. I was also thinking whether this could have been a defect with the black wires, you scenario of possible screw loosing over time fits the bill. I will check the tightness of the screw when i get to the tub again but it may be welded from the short so not sure if that will give me a definitive answer. What blows my mind still is that two 10ga wires melted together and burned off and that did not trip the breaker or blow the fuse on the control panel. It seems to me that the protections that are supposed to catch that sort of thing are not really working...

Thanks for the reply - posting a few more pics here... In looking further at pics I think you are exactly right about J8 - it looks to be heater in. At least that might mean the water pump MAY not have been the culprit. The incoming power wires can be seen on one of the pics below - the black is burnt a bit from the fire on the other side, I will cut a few inches and strip fresh wire. I have plenty of length available.

my bad, fixed the pictures - thanks for letting me know

Certa 780 with 2 pumps... Woke up one to day to find no power to the hot tub (display is dark). Breaker was not tripped. Turned it off and opened the control board box to find the two black wires going from the outside power connector(TB1) to J8 and the SC-30 fuse melted and burned out right after the connector. Shockingly the fuse appears good - could not test under load but tested continuity with fuse removed. After the shock that 2 10ga wires managed to melt and burn without tripping the breaker or the SC-30 fuse wore off, I looked at the board more closely and do not see any other obvious/visible damage. Looking at the circuit diagram, it appears the wire from TB1 to J8 is bypassing the fuse - am I looking at this wrong? Leads me to think that the problem was on that side of the wiring... What is J8 powering? Outside of the control panel box, I see the flow sensor was likely dripping as it is right over one of the pumps and I see some corrosion on the box where the power goes into the pump assembly. I wonder if the pump shorted and led to the short in the panel box. Apart from the idiotic design decision to place the pump power box right under the flow switch, the other ridiculous thing is that right about a year ago we had a problem with the flow switch and I thought of replacing it myself but since we were just inside the 5yr warranty we called the authorized dealer to repair under warranty and it appears they did not screw the flow switch tight and it was dripping... Just blows my mind to think about the lack of attention or competence... Anyways, I am wondering where to event start with this thing now...Should I even bother replacing the two burned wires? It is hard to imagine that these wires melted without damaging the board? Since I probably have some wire laying around in my work shop, I am wondering if it is worth disconnecting the power from the pump, replacing the two burned wires at the control panel, and powering up to see if anything is still operational. Any help is greatly appreciated!

Awesome, thanks! I will see how it goes and will report back. chem geek - I really appreciate the help and advice! MG

Chem Geek, Thanks for your response - your post is as always full of wisdom. I apologize for going silent but I went off-grid this weekend more than I was planning to. I do not have a ozonator. What is CO2 outgassing? You refer to it as the use of jets - our system is set to cycle twice per 24hrs, but honestly I am not sure how much time on each occurrence, will check next time. One newbie question - I have the air vents set to full for when we use the jets - does that mean that when it cycles it uses that setting as well?. It sounds like the outgassing will lower FC but raise PH? Now back to issue at hand... The plan currently is that the maintenance person will drain and refill after each rental, balance the water, open the the dispenser just a notch(our dispenser is of the type that can be fully closed or can be opened just a tiny smidge if you want) and set the temp to 80F while there is no renter. Then at the day of the renter arrival, he will balance the tub, set the temp to 102F and open the dispenser more depending on the number of people arriving. So obviously this is not an exact science because there may not be a direct correlation between the number of people renting the house and and number of them that will use the tub, but this is the best guesstimate we can use. For example, on the current cycle, the renter comes in on Friday and leaves Sunday. The water is replaced on Monday and tub is balanced, set to 80, etc. Next renters come in on Friday, so Friday morning the maintenance guy comes and balances the tub and raises the temp and opens the dispenser more. Whole thing repeats the following week... So if I understand this correctly, other than guesswork on actual spa usage during rentals, the other main concern from our approach will be the increased acidity from the use of trichlor. I am not worried the potential to build up CYA levels to where they make the FC ineffective because the water will be replaced fairly offen, am I correct on this? What level of acidity do I need to be concerned about? I know the target is 7.4-7.6, but what is a danger/concern level? The taylor kit did not make it in time for this weekend so I could do any precise measurements. I will report back the next time I can make some. I understand there are shortcomings to this setup when you do not fully control the environment on a daily basis, but we have to come up with the best option available out of a pool (no pun intended) of alternatives that does not contain a perfect solution. Is there another approach that you would recommend for a rental? Thank you so much for your help! MG

Hi all, I am a new member and the first thing I want to say is thank you for all the great resources on this forumI It has helped me learn a lot about hot tubs water chemistry. I have a 300 gal newish hot tub in a rental house that my family uses as well. We have a maintenance person that services it and drains the water after each rental. He is very adamant in recommending us to use chlorine for sanitizer. He would use dichlor at start up and then put in the 1in trichlor tabs in the floating dispenser to maintain the chlorine level. He will be going basically once a week to balance the water and also balances the water before each rental. I have read many of the write-ups here on chlorine based systems and the recommendations not to use the trichlor tubs in hot tubs and I asked him about the acidity, etc. He explained that because of the frequent water changes (last month we had 4+water changes) he believes the acidity will not be an issue. I called the place that we bought the tub from and they confirmed that in a rental property they will not consider use of trichlor to be something that will void warranty. So I wanted to see if anyone has experience with a situation like this. I have read about a couple of people using trichlor in their tubs and I guess if you have weekly checks to fix the PH then this should work - am I missing anything? Another question - how much acidity does trichlor add? Our spa is ~300 gal, how much FC and acidity will a 1in puck add? I apologize if this is said somewhere, I looked and could find that information. I looked at the thepoolcalculator.com but could quite figure out how much trichlor is impacting PH. Since I go to the house 1-2 times per month, I plan on removing the dispenser upon arrival and using dichlor/bleach while we are at the house in order to relieve the acidity impact from trichlor. I have already ordered the Taylor test kit and plan on measuring/adjusting the water balance whenever I am at the house. Speaking of which, is there any other effect from Trichlor - is adding anything else other than FC and CYA that I need to be measuring? I would obviously pay special attention to PH... Is there a benefit to using more Borax - I know that it raises the PH a bit and also borates help stabilize PH? I asked too many questions already so I will stop at this time... Any help and thoughts are greatly appreciated! thanks, MG