Our Nearly New Furnace Had a Hiccup


Lennox SLP98DF070V36B-01 Furnace

Our house power went out for a couple hours late Thursday morning. No telling what caused the power outage, the weather was fine. I assume someone either took out a power poll somewhere or a powerline transformer blew.

When the power came back on, everything but the house furnace worked OK. The house furnace had electricity and gas, but it would not turn on. We had a new Lennox furnace put in a few years ago when our old furnace from the 1960s stopped working.

I checked the thermostat and it was sending the “turn on” signal to the furnace. I noticed a single letter LED inside the control box of the furnace that was running through some kind of code, but the code made no sense to me. They did not match any of the codes that were on a troubleshooting sheet on the front of the furnace.

I called the shop that had installed the furnace and they said the earliest they could come out would be December 26 and the minimum charge would be $120. That would mean eight days with no heat. I told them I would try to find someone who could come out sooner. I eventually got in contact with a repair company that would send someone out the next day. That still meant a cold night and a very cold wake up in the morning. We live in the South SF Bay Area, but it is currently 54 F (12.2 C) outside, and the low overnight would be 34 F (1.1 C).

Even with someone coming the next day to fix the heater, I wasn’t going to freeze overnight without trying everything I could. I took another cover off the furnace and discovered that the LED readout is upside down. It was displaying the code H E228.

The manual for the furnace says Error 228 means the furnace is “Unable to perform successful pressure switch calibration.” Under “Action Required to Clear and Recover” in the manual, it said,

Retry after 300 seconds. Error counter cleared when exiting lockout, unable to perform pressure switch calibration. Check vent system and pressure switch wiring connections.

So, I kept trying to restart the furnace every 5 minutes. I did that by manually turning the furnace power off and then on using a switch that I had the furnace people install back when they put in the new furnace. Every time I turned the furnace power on, the LED told me that the controller was calibrating the furnace pressure switches, and then it would error out again with the H E288 code again. I kept at it for about an hour, when all of a sudden, the furnace came on after the calibration cycle. Hooray!

I let the furnace cycle several times on its own to make sure it was working correctly before canceling the appointment with the heater service person that was going to come the next day.

The furnace has been working correctly for several hours now. Apparently, there was a spec of dirt or something that was causing the pressure switches to not be able to calibrate. After all of my restarts, the dirt particle apparently went away and everything is working.

Newer furnaces are seemingly fussy that way. This furnace had a problem about a week after it was installed. The installers came back out and found some PVC particles from the installation that were causing trouble in a vent. They cleaned the vent out and the furnace had been working until this latest power outage.

Have you had trouble with your furnace this Winter?

22 thoughts on “Our Nearly New Furnace Had a Hiccup

  1. Hi Bryce, Glad to hear the furnace is working properly again. We still have the original burner in our house witch would make it a bit over 20 years old. We have been keeping money aside for the day the sucker dies on us. I have always kept it clean and part of our yearly contract with company who installed it is preventive maintenance. So I believe that has helped it last longer then most (that’s what they tell me anyways). After looking at the picture of yours appears to be an efficient system. So good luck the rest of the way with it. Nothing like staying warm in the winter and having hot water is always a bonus. Have fun and stay warm my friend.

    1. Hi Mike, a well-maintained twenty year old furnace is probably good for at least another 20 years. Even though it’s nice and comfy in our house now, I’m having a hot chocolate just because. Only thing missing is a candy cane to put in the hot chocolate.

  2. The R.P. furnace went out a couple years ago. Turned out to be a power-limiting transformer. “Power-limiting” in this case means there is no fuse in the circuit – the transformer acts as the fuse and burns out. Great design, huh?

  3. Way to DIY the repair, Bryce. That’s a great catch with the code being upside down…I probably would have never noticed that.

    Knock on wood, our 1994 heater/AC combo is still trudging along…

    1. Hi Done by Forty, Thanks for the nice comment. If your heater/AC combo were just a forced-air gas heater, I would expect it to last 40 years. The addition of AC could make its lifespan shorter. I don’t have any experience with combo units, but central AC units usually take more maintenance than central heating units. Hopefully, you will get another 20 years out of it.

    1. Hi Brian, I couldn’t think of anything else to do other than delve into the venting system, which looks a bit complicated. It was either keep messing with it, or give up, get cold, and pay an expensive repair bill. I am not one to easily give up.

      Thanks for your comment.

    1. Hi Kurt, Yes, I was a little upset at the thought of waiting a week. That’s why I called a few other places. Because of their Grinchiness, I will probably NOT use the original installers ever again.

  4. I just bought a home and was disappointed to discover a rather large leak in the HVAC plenum leading from the inside air handler to the ductwork. The home inspector should have caught this but failed to do so. I am now looking at $400-$600 to replace the plenum!

  5. I have never had any experience with furnaces before so I cannot really know what it is like. But what I can say is that I am glad for you that your furnace is working again. Saved you a lot of trouble, didn’t it?

    1. Hi Jen, It not only save us a lot of trouble, but it saved us having to bundle up and see our breath in the house for several days, as well as having to pay at least $120 for a service call.

      Thanks for your kind words.

    1. Hi Moneycone, Thanks for your comment. If it happens again, I hope I know what to do. There’s no guarantee that my start-up fix will work again, although the furnace has been working fine for the past three days.

  6. Strange how newer, more technologically advanced pieces of equipment also seem to have more ways to fail, isn’t it? Facing a night of cold, I would have kept at it for hours…lol. The oddest thing to me is that the installation company wouldn’t try to fit you in somehow earlier – having no heat is a rather serious predicament to be in!

    1. Hi Brock, I often find that the bells and whistles that are added to new appliances, vehicles, and what-not, are all the things that typically break. And yes, I was rather upset at the thought of at least one night, and possibly more, without heat.

      Thanks for your comment.

  7. The pressure swatches ar terrible! Our furnace was not 3 years old before we had our first problem. You have to take off the hose from the housing that connects into the pressure switch and blow into the switch. The furnace stops working and I have to do this once or twice every year. Really a bad design for a top of the market furnace.

    1. Hi Marc, When our furnace is working, it works great. We had trouble with it 60 days after installation, and now this startup problem. You may be right that blowing into the pressure switch hose could have fixed the problem.

      Thanks for reading and commenting.

    1. Sealing your heating ducts can be an effective way to improve your existing heat system. If you have a home energy audit, the auditor will do a blower door test to assess the air leakage from your duct system. Do not allow anyone other than a trained professional to conduct this test in your home.

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