Diagnosing and Fixing an Infrared Sauna

Here’s a project not everybody will find terribly interesting, probably like when I wrote about replacing a water heater in Resist Zine.  However, it was a bit of a learning experience for me, and since I was already taking pictures so people could help with the diagnosis, I figured I might as well share my experience.

A few years back I bought Rachael an infrared sauna.  Most years these Minnesota winters are really tough on us.  The days get so short that if you have a normal job you barely see the light of day during the week.  The temperature can drop below zero for days at a time with the wind making it feel even colder.  Then there’s the snow.   Some years it seems like you spend half the winter shoveling, and the piles get so big you run out of places to put it all.  It seems like you’re always cold.  For some of us, it really starts to wear on our psyche.  Some folks use sun lamps to help.  We figured an infrared sauna would probably do the trick.  We found a used one that a couple were selling because they were losing their house and moving into an apartment.  I kind of felt like a vulture buying it from someone who could no longer afford to keep it.  It broke down into 6 panels and we loaded it into the van.

She’s been using it the last couple years pretty regular.  Just recently, a few of the heating elements started working intermittently.  Sometimes they would work, sometimes they wouldn’t.  Sometimes when they weren’t working, I would go on top and check the connections.  3 of the panels had heating elements, plus one on the front of the bench, so each had power connections like the 3 prong power cords on desktop computers.  I would pull them apart, take a look, and put them back together.  Sometimes just doing that would get them going again.  I would think that the problem had been solved, and then it would happen again the next time.  When they were not working more often than working, I figured I’d better dig deeper and see what I could figure out.

The heating elements that weren’t working were all on the same panel.  There were two on the back wall, and the one on the front of the bench that plugged into the back wall.  Also on the back wall was the control panel for setting the temperature and timer.  If it was something with the control panel, I figured it would affect all the heating elements, not just the ones along the back wall.  The connection seemed to be fine, so it must be something else.  I figured the only way I was going to find out was to start taking it apart and tracing the wiring looking for problems.  I thought maybe I’d find a fuse broken or loose fuse connection or something.  Only thing was, I couldn’t seem to find a fuse.  While I was pulling stuff off the top, I found the owner’s manual which showed where to find the fuse.  The problem was, the owner’s manual was wrong, and it wasn’t where it was supposed to be.  However there was one bit of useful information in there, a wiring diagram.  Two actually.  The second one seemed to make sense.  It showed 3 heating elements on one fuse, and 2 on another.

2nd of 2 Electrical Diagrams

Since the fuses weren’t where they were supposed to be, I started unscrewing the top of the top panel.  Sure enough when I got enough screws out to pull up one edge, I could see an electrical box.  I tried to take out a few more screws so I could pull it up further and open it, but the electrical box was screwed shut too.  So I had to take the entire top off, and then unscrew the lid of the electrical box.  That’s where I found the fuses.  They weren’t glass ones, so it wasn’t readily apparent if they were burnt out, but since the elements were still working intermittently, I didn’t figure that could be it anyway.  Also, the connections for the fuses looked just fine.  Back to the wiring diagram.  There was only one other thing that made sense.  Those 3 elements also had their own relay.  I’d seen relays go bad on motorcycles (also the places I’ve seen fuse connections go bad), so I figured that was the culprit.  On a motorcycle when that happens, you can just jump the poles with a screwdriver, because it’s just for the starter and it’s just a battery.  I was a bit apprehensive about trying the same thing with wall power.  Instead I loosened the screws and stuck a piece of copper wire between them, effectively bypassing the relay.  Then I turned on the sauna and waited to see if the elements would heat up.  The first time I jumped the wrong relay and nothing new happened.  Then I switched the jumper wire to the other one and got all the elements to heat up.

Jumping the relay

Now I just had to figure out where to find one of these relays.  I’d posted a picture on Facebook while I was diagnosing this to see if other folks had differing ideas.  The opinions mostly agreed with the relay being the most probable cause (even though they’re solid state and almost never fail) with some folks saying to check the connections, maybe use some contact cleaner.  I posted again to confirm the relay diagnosis, and an acquaintance said that he had a bunch of those from an old project.  Still not being 100% sure of my diagnosis, I was thinking about buying new ones, just to be sure I got working ones to test my theory.  He confirmed that he’d tested them and knew they were in good working order and sent me a couple the next day.  (Thanks Matt!)

We had a busy schedule, so it took me a couple days to get it installed, even though it’s a super easy job.  Rachael freaked me out by telling me that she’d kept using it with the relay jumped.  Yikes!  I should have pulled that jumper wire out instead of just unplugging the sauna.  After she told me that, I got right on top of getting that new relay installed.  There’s nothing too complicated about it.  I used a socket driver to remove the relay from the box, and then one screw at a time transferred the wires from the old one to the new one.  Rachael used the sauna yesterday and informed me that everything is working fine.  Now I can close up the electrical box and put the top of the sauna back on.

Replaced relay