Tubcat Posted June 6, 2020 Report Share Posted June 6, 2020 Before I go forward with an expensive support call, I wanted to see if anyone else may know what is going on with my tub. The heater works fine, but randomly every couple of weeks, I will get the dashes on the display indicating hi limit tripped, and the heater will be shut off, while everything else works. I have replaced the filter, replaced the hi limit sensor, both with brand-new parts and it is still happening. I have taken the heater relay board out to inspect, and there are no obvious flaws to me and I had also checked all wiring with a multimeter (to the best of my ability - not an expert here), but 240 is going to the heater when it is on. So, does this sound like a heater relay board problem, a main board issue, or is this something else? Edit: Turning power off and then back on will immediately fix the issue for days to weeks until it happens again. Circulation pump seems fine as the circulated water output is strong. Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted June 6, 2020 Report Share Posted June 6, 2020 I would suspect the circulation pump. Quote Link to comment Share on other sites More sharing options...
Tubcat Posted November 18, 2020 Author Report Share Posted November 18, 2020 Replaced the circulation pump and the problem still occurred. The latest thing I am checking is whether it is the pressure switch. This is in a Low Flow Trombone Heater, but for now, after spending time on every other solution, I have simply bypassed the sensor on the circuit board with alligator clips and will see if I get the same error. 5 days so far with no problems, but the error can sometimes take a few weeks to occur. Anyone replaced a pressure sensor in a Low Flow Trombone Heater? Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted November 19, 2020 Report Share Posted November 19, 2020 On 6/6/2020 at 8:55 AM, Tubcat said: replaced the hi limit sensor, both with brand-new parts a So, did you replace one or both? 8 hours ago, Tubcat said: Anyone replaced a pressure sensor in a Low Flow Trombone Heater? It just screws in on the outside. Disconnect the wires and unscrew it. Have the new one ready to screw in. Quote Link to comment Share on other sites More sharing options...
Tubcat Posted November 19, 2020 Author Report Share Posted November 19, 2020 I have replaced the: filter (they were always clean, but got a brand-new one and a back up which is relatively new), high limit sensor, circulation pump (the older one was noisier and 10 years old, so I figured the new one was going to be needed soon anyway). The trombone heater look like the following, and the pressure switch/sensor is in the black casing. I just wasn't sure how easy it was to replace as all the pressure switch examples I've seen are visible when the tub is opened up: Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted November 19, 2020 Report Share Posted November 19, 2020 11 minutes ago, Tubcat said: examples I've seen are visible when the tub is opened up: That's the one in my garage I went to check before replying. Can't say I've ever seen one of those. Have you tested the switch? It should be closed (have continuity, 0 ohms on an ohm meter) when the circulation pump is on, and be open (no continuity, no reading on your ohm meter) when it's off. 16 minutes ago, Tubcat said: high limit sensor, I always recommend replacing both sensors at the same time. You can test them with an ohm meter, set to 20k if adjustable. Be sure heater us off for at least 10 minutes before testing. Post results. An intermittent issue can be a serious PITA to track down. Maybe @castletoniahas some insight. Quote Link to comment Share on other sites More sharing options...
castletonia Posted November 19, 2020 Report Share Posted November 19, 2020 Assuming the pressure switch is good, I would lean towards the main control board, but I'm not confident enough to say go replace it since it is a $400 circuit board. Heater relay boards don't typically work intermittently, either it works of its fried. Quote Link to comment Share on other sites More sharing options...
Lawnmedic Posted January 10, 2021 Report Share Posted January 10, 2021 Tubcat any resolve with this issue as my Caldera is doing the same exact thing. Thanks! Quote Link to comment Share on other sites More sharing options...
Tubcat Posted January 10, 2021 Author Report Share Posted January 10, 2021 Nope, but I believe I have exhausted everything but the actual main board at this point. I've done the following, (a recap of the above posts): - new filter - new high limit sensor - new circulation pump - checked the heater relay board for obvious signs of any issues - bypassed the pressure sensor as I didn't want to replace something that didn't need replacing. There are also no trees in the backyard or near me, so the water has never had leaves or any other sort of debris in it, and we enter the tub from a deck. So all signs point to main board issue. Everything works great otherwise, but every 3 weeks or so I have to turn power off and back on to resolve the heater being shut off and the 3 dashes on the display. Doing this has always resolved the issue over the last 3 years. The only frustration is that I'm in the North, so during the cold Winter months I have to check every day that the heater is still running and present the tub from freezing. Quote Link to comment Share on other sites More sharing options...
Paul Caliente Posted March 7, 2021 Report Share Posted March 7, 2021 Tubcat, I have this exact same problem, the spa may run for hours or days before the error occurs. My circuit board is identical to the picture you posted. I started the spa yesterday and monitored every hour for 8 hours, the temperature stayed at the 99 degree set point and it stayed running. I checked it at 24 hours and evrything looked fine. At 30 hours, I checked it and the 4 dashes were displayed again. Powered the circuit breakers off then back on again and it’s running for now. I too am very hesitant to replace the control board due to the cost! I’m very interested in hearing your solution. Quote Link to comment Share on other sites More sharing options...
Tubcat Posted March 7, 2021 Author Report Share Posted March 7, 2021 The 'solution' is to check often, especially during cold winters, and turn off and on when the dashes appear. The only option I have now is to get a new motherboard, which I haven't bothered doing. Turning off and on has worked for three years now, so I've accepted that for now. The tub is 2008/2009, so I'm done putting money into it. Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted March 8, 2021 Report Share Posted March 8, 2021 On 1/10/2021 at 4:24 PM, Tubcat said: I believe I have exhausted everything but the actual main board at this point. I've done the following, (a recap of the above posts): - new filter - new high limit sensor - new circulation pump - checked the heater relay board for obvious signs of any issues - bypassed the pressure sensor as I didn't want to replace something that didn't need replacing. On 11/18/2020 at 10:38 PM, RDspaguy said: always recommend replacing both sensors at the same time. You can test them with an ohm meter, set to 20k if adjustable. Be sure heater us off for at least 10 minutes before testing. Post results. I can't help but notice that you did not test or replace the temp sensor. Sensors can be tested using an ohm meter if you want to verify before buying parts. The dashes typically indicate a sensor issue, which can be the sensors themselves or a flow issue. It could be the board, but without testing everything you'll never know. 1 Quote Link to comment Share on other sites More sharing options...
CCGifford Posted May 10, 2021 Report Share Posted May 10, 2021 I have the same exact problem with my tub same age and board. I did have to replace my heater relay board, I also replaced flow switch, filter, circulation pump' What is left control board High limit temp sensor Are there any other ways to test or check. This has been a problem for a year now, recently now my 2 speed pump will not run at low speed. This makes me think the board is going out Thoughts ?? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.