My Gas Water Heater Story - A possible Lab?

I have a recommendation for a possible “Lab.”

A few days ago I noticed my gas water heater had some indicator lights on. It was an error code for “System in lockout.” I did not know the water heater was not functioning until I saw the LEDs. Before researching the code I increased the temperature to make the WH turn on. It would start up and turn off in less than one minute. After it shut off, it would try again after about another minute and turn off again.
From the WH manual, “System in lockout” could be one of these problems:

  1. Gas supply is off or too low to operate

  2. Hot Surface ignitor not positioned correctly

  3. Low Voltage to the water heater

  4. Electric Polarity to unit is incorrect

Today I had to take a cold shower and that got me in gear! A little Googling and Youtubing at 4 am before work led me to the culprit, a dirty flame sensor.
My WH normally has 10 minute ON cycles. I think Sense could EASILY pick up a series of irregular (short) 1 minute cycles and highlight a possible problem with the WH. From the web app I did go back and found the 1 minute cycles, when the WH was trying to start up. I don’t know what the ratio of electric to gas WHs is, but a lab could help up to 50% of people see a problem when it happens. At the very least Sense did help me troubleshoot the problem.

I just cleaned the flame sensor, the burner, and enclosure, and now the water heater is heating! Only problem now is Sense is picking up the WH in OTHER!!!

Normal Operation

Short Cycles due to dirty flame sensor


Similar could be applied to a furnace induction motor. For instance if the induction motor started but the blower motor didn’t. I’ve always wondered why Sense completely merges components of a device instead of a pie chart bubble. In your instance repetitive short cycles when there shouldn’t be.
I imagine something like this would require some significant algorithm and modeling changes in order to determine which specific cycle signatures are normal vs abnormal. An oven, stovetop, electric blanket, coffee maker, etc… all cycle on and off repetitively. Motors such as a modern washing machine, some pressure pumps, also cycle repetitively. Would be a great feature though.

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Pretty cool @Kevin_K - I’m sharing this with our team!

After the cleaning I lost the water heater detection for a couple of days, but it’s back!

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You must have a power vent HWH then? My gas HWH has no electricity going to it at all. I needed to replace it almost exactly a year ago, and we were debating doing with a hybrid heat pump water heater. A. There’s no electricity running to it now, so I’d need to run conduit and a new 220 breaker, which my wife was VERY skeptical about, and B. despite telling plumbers we were interviewing that we were interested in a heat pump, none could tell us about them. That didn’t instill any confidence in getting that unit maintained over the years. One was telling us we were thinking about a power vent, and we told them no. To their credit, they called someone else in the company who did know about heat pumps, but said they’re not common in our area. I caved and let my wife get an equal replacement to our normal 55 gal nat gas unit. Of course now were adding solar…

It is definitely a power vent water heater. I’ve started shopping for my replacement as mine is over 17 years old. The cleaning I did last week was the first problem I’ve ever had with it. I’ve considered tankless but I’m so happy with the reliability I’ve experienced so far. There’s also the energy consumption…The usage meter tells me It’s using 0.3 - 0.4 kWH a week. I really don’t think I could easily get something more efficient. At this point in my life I’m ONLY looking for things which lead to the smallest utility bills.