Tom 7506

Yeah, that's a pic of the new board before I noticed they were wired differently. The old card and the new installed card have white AC to W1. I checked and double checked they were wired the same...I don't have an installed pic. It's 25 miles away. This is a pic of the old board which I was going to try to repair. I was also struggling with the dip setting A5. dips.pdfdips.pdf I assumed the pump ran on high and low speeds. Panel: I know the temp up and down buttons work. The lights can be turned off and on. When an error code is thrown, the jets button does nothing as the pump stays on high. Could a bad panel cause overheating? Your suggestion above about a stuck relay? The old card had no obvious damage on the back so I tested both with a 9v batt and continuity tester. I got a good "click" and the circuit closed on both. Tracing the circuit, both relays get the same signal from J12 so why only 120v when I tested. My brain hurts.

Update: ARGGG! I checked the hot tub the next day and was pleased to find it was at 104°. A few days later, we heard from a guest that it wouldn't awaken from "sleep" and was too hot. I went back yesterday and found it had a code HH (different from the first code OH), 120° and the pump was on hi speed. That explains why the control panel wouldn’t respond. I'll note here that the OH means the spa saw 110° and HH means is saw 118°. Both times I recorded temps quite a lot higher. I have now installed a replacement OEM heater tube and OEM main circuit board. The new circuit board has identical dip switch settings and jumper wires. I also verified the replacement board has identical model and version numbers. All the jets are open and the water is roiling so it's certainly not a flow issue. I turned off the power for now. When I received the new board, the jumper wires were configured differently from the old. I called Spa Guts support and they basically said if it was working with the wires in the old configuration, go with that...so I matched up the connections using the old board as a template. Is this a problem? So, I’ve run up against 2 issues so far. First, the coil had shorted so I replaced it with a new OEM heater and sensors. Second, 120v power was going to the coil even after the tub reached its set temp. I suspected a stuck relay on one side of the 220 power to the coil so I replaced the controller board. Plan: When I go back, the tub should be cold. I'm going to power it back up and do some checking. First, I’ll pull the tabs to the coil and make sure I have 220 to the coil. I’ll also make sure the amperage across both sides of the 220 are roughly the same. What else should I look for? It's going to take a few hours to get to 104. Question: why in the world is power continuing to be applied to the heater coil after reaching operating temp. I am aware the temps I’ve found are dangerous and will make sure we won’t allow any users until I get this figured. I appreciate your time look and welcome your help…again! Tom

It appears all the default timeouts and filter cycles are set to default: 2 hour filter cycle, 2 hour low speed and 15 minute high timeout. I was thinking, once you mentioned the stuck relay, it might have contributed to the shorted heater coil. I just don't know the history of it overheating as the rental just came to us recently. So now I've ordered a new board to replace the old one and a new coil to repair the old heater. I'll look into replacing the relay so we have spares.

Yes, water was at 109. Yes, I verified the coil was centered in the tube, nothing was touching the sides. Sounds like I'm pulling that board. I'll get one on order. Do you try to repair these or just toss them? Thanks for the prompt response! Tom

I have a hot tub with a Balboa VS500Z controller and a ML200 control panel. At first, I couldn't reset the breaker. After some troubleshooting I found the heated coil had shorted. I replaced the exact OEM coil. I checked on it the next day and it had an OH overheated code. I followed the Balboa troubleshooting chart for OH and didn't find anything wrong. With the tub set to keep the temp between 102 and 104, I found the tub at 109° on the way to overheating again. There should not have been any voltage to the heater. I clamped both power lines to the heater and found one line running 120v at 12 amps. The other line had no voltage. Am I correct in thinking there's an issue with the circuit board. I read somewhere the problem is almost always the front panel. Help!