How to diagnose and repair a hot tub heater

Heaters is our next segment. So we are gonna take a look at a heater; some tests and troubleshooting on the heater and replacing a heater. So we’re… Lets get some access, because we’re gonna wanna take a look at some of the connections inside. Take the plate off. We’re looking at the pack. Here are your two heater leads, right here. You’ll notice right off the bat that there’s two wires. There’s a one lead with two wires, second lead with two wires coming off of this one as well. It’s going into your plug, so when you pull your plug off, you’ll notice again that there’s four pins. So we have four power pins, and the flat one is your ground. So these four power pins obviously when they go back to the heater or to the elements are going to be going back together again. So when you’re checking the heater for it’s continuity we’re going to have to match those up. I’ve got a heater right here. So what we’re going to check is the continuity of this heater. Place that so you can somewhat see it.

Now, we look at these pins; if I go to these far two pins right here, those two pins are connected to one side of the elements and you’ll notice right there, that I have zero resistance, well .1, which we can classify that as zero. And if I can go to the other two remaining power leads which will be this one and this one, again, I’ll have zero resistance because they’re running the same line to one side of the element. Now if I cross over, I’m going to end up. . . Right now it’s in the 10.9. We’re going to run anywhere from 9 to 11 point something. That’s the resistance that you’re gonna wanna be coming across for your heating element. So, you’re gonna want your resistance sitting around 10. Then we have to test off of the ground, we wanna test from to ground to all four of those power leads, and you should get nothing. There should be no buzz and no current going across whatsoever because you don’t want power going into the ground. You can also check any of your power leads and know that there’s no current than can pass from one of the power leads to the ground, so that’s sitting fine.

Alright, we’re gonna plug the heater back in. Another test, the heater must be plugged in so if you don’t have the heater hooked up whatsoever and you check, you could get a reading of your 240 volts; but it’s false and it’s under milliamps. So have that plugged in so it’s under-load with the heater, check across your voltage see that you got voltage going to the heater. So you’re going to read your voltage also this one isn’t plugged in, I don’t have anything for you to read. Yes I got voltage going to the heater, the icon is saying that the heaters on. You can switch to average. Have an amp meter on you always. Go across your leads. You should read, 20-21 amps. If you have less, then you have less wattage of heat going in, but 20-21 amps is your 5500 watt element. Now, we’re gonna run through all the build for all of that. If there’s no amperage going and you’re voltage is going and the heater icon is going, obviously your heater is failing; or if you have a direct short, like the breaker is tripping immediately, so you check from ground to any one of your leads and you’re getting continuity across there, then you need to replace your heater as well.

So, we’re gonna go over replacing the heater. Heater is sitting behind this pack, and it’s possible to change the heater without taking the pack out, but for filming reasons we’re going to remove the pack so you can have a better visual.

Now we have the pack removed, and I’ve got some visual for you guys to see the heater; so we’re gonna go about removing this heater. Gonna take the leads off the pressure switch. This bald is full of water. We have unions on both sides, or bald-outs, and balds. So you got a bald-out on your suction side, bald-out on the pressure side. Gonna close those off to eliminate a spark when draining. Remove these unions. Remove your high limit probe. When removing these unions, and unthreading them, when you get to the end, you’re gonna wanna watch, sitting right inside, you have a flat gasket o-ring just sitting in there. You can have a gush of water that comes out so you want to make sure that water flows out, your o-ring doesn’t get washed away or washed underneath the pump and lose it.

So make sure you save those and set them off to the side. Pull your heater up, you’re gonna take a flathead screw driver and disconnect the ground wire. And you have your faulty heater. You’re going to take your new heater, and place the used pressure switch onto it, threads, on your pressure switch are a tapered thread. It’s a tapered pipe thread on both sides so you can put a bit of Teflon tape, but if you just continue to tighten it as you tighten it, it will actually become a tighter fitting. Pressure switch is put on, ground wire is hooked up. You can see here: heaters all come with new heater tail pieces and the flat gasket o-rings inside here. So when I thread this on, that’s a brand new heater tail piece, you can take that and put it in to stock and you have a brand new flat gasket o-ring. So you might as well, just for cautionary measures, always use the new o-rings or put it in to inventory for a later date.

Now the unions snugged up on both sides, you can take your high limit probe and then take our leads for the pressure switch. Plug those both in. Take our pack, we’re going to mount it back in place; but what we’re going to do right now is plug all the equipment in. Plug all the equipment in, turn the pack on, run the spa, open your bald-outs. And just make sure that it fires up so now you can turn it on, fire the spa up, make sure there’s not an air lock, have the heater running, and while the spa is running and heating you can put the rest of the bolts in, put the pack back in to place, put the cover plate on, and you know it’s ran for a couple of minutes before you leave the problem.

I’m just gonna quick run down on some key points, your power leads two of them share, so these two outside share, these two share, for each side of the element. You’re checking voltage, make sure the heater’s plugged in or you’re gonna get a false reading. Check your average is roughly 21. Continuity is going to be roughly 10. And have a great day.
Oh, one last little note is don’t forget to always be checking for leaks; we’re at the spa, we’re looking around so if we’re replacing the heater, there’s total point in taking a look around the rest of the spa, see if the works, what you just worked on. So once it’s up and running we got everything sealed up, we know it’s going good, take a look back at the last unions you were just working on, and even bring the customer down, explain to them where the unions are, how the unions work, the o-rings, etc, so the customer is comfortable working on the o-rings or the unions get the o-rings in them to run. Bye.

More details about the type of heater used in Arctic Spas can be found here.

More hot tub repair tutorials and videos are here.