The itsy bitsy job-security spider

Written on: October 1, 2012 by Wayne Lawrence

…the itsy bitsy spider
hid in the burner rail,
got himself real comfy,
made the burner fail,
along came the technician
attempting a relight,
but due to lack of training,
 received an awful fright….

I yelled up to my partner, Roy, through the many years of dust that rained down from the trussed ceiling onto our heads and the top of the never-had-been-cleaned suspended unit heater we were just working on.
“Yes, I’m OK. You?” Roy yelled back down to me as he was shaking the dusty hair coloring from his head (I must add, it made no difference! Grey hair, grey dust—he looked the same! Roy, you’re the best and this job wouldn’t be the same without you!) Anyway, we were there to perform seasonal maintenance and system start up on the many gas and propane units this company had. This heater was in a prefab garage that served as a storage area for construction machinery, and it hadn’t been in use for several years.
We had just replaced the gas valve, pilot assembly, installed a new thermocouple, tubing assembly with fittings, cleaned all the ribbon burners, lit the pilot, closed the cover, and started the unit. It had a nice looking blue gas flame on the ribbon burners, with no flame lift. All looked good from what we could see with the cover on. We were waiting for the fan control to make on temp rise, checking to make sure the fan worked. Roy was still 15 feet above the floor at the unit heater standing on a work platform, and I was now at the thermostat when we became better acquainted with our new job security making friend—the “yellow sac spider.” The flue pipe was now lying on the floor, having just missed me as it fell; the heater’s service door was open, swinging on its hinges, and the heater was now in non-working order—again! So much for “productivity” this day. Thankfully, Roy was on a platform instead of using a ladder like we have done so many times in the past working on these suspended “coffins.”
Until now, I had never known the name of the spider that likes the odor of gas, natural gas, and propane. My thoughts shifted to write about this as I watched one run across my van windshield while on lunch today. The weather is changing, and he is probably now a tenant in my van somewhere! Of course, while I’m heading to a service call, he’ll probably decide it’s the perfect time to drop down from my van visor to make sure I’m fully awake! This is the same eight legged creature with the Latin name Cheiracanthium Inclusum, that causes me to invent curse words each season while trying to start my BBQ and getting the look of “Now what?” from the hungry!

I was now looking on the internet to try and find a way to keep them out of the many greenhouse heaters that Roy and I work on this time of year. I happened to find, while doing my research, that this creature is responsible for the job security that the Mazda Corporation was not too happy about at the start of 2012. However, I feel the factory service technicians should be as grateful as I am these days to have work in this very tough economy. I discovered that 65,000 Mazda 626 cars had been recalled due to a design that lets this creature finds its way into the fuel vapor system.
We learned a very valuable lesson that day. While we have had to clean these spiders out of our BBQs each year, Roy and I took for granted that these spiders are able to get inside the small burner orifices and restrict the flow of gas in pool heaters, floor mount furnaces, and even suspended unit heaters. That is what happened to us while working on that suspended unit. The last ribbon burner orifice was severely restricted—the spider laid its eggs inside. The other ribbon burners lit, all except that one, and the gas was slowly pooling inside the cover, until the moment the air/gas mix was just correct.
Because of this lesson, we remove and clean every orifice while performing seasonal maintenance whenever working on outdoor appliances. You would be amazed how many are found to be restricted. We have tried “roasting” them clean with a torch, blowing them out with compressed air, using small brushes and wires to clean them, but the best and most thorough way is to remove, clean, and reinstall the orifice. For any unit that happens to start with a delay or fails to relight because it blows out the pilot, a check for spiders would be first on my list.
There is no better teacher than experience. I am sharing this in hope that you keep “nature’s job security” in mind when working on any gas, or propane fired appliance, and remember, these spiders also bite!
Stay safe, Wayne