Talk about quality control!

[etpm]

My furnace quit working. Looking online I found a site that advertises experts who can help. Offhand I don't remember the site but I did get good advice and I think it cost me 33 bucks. Way cheaper than a visit from the furnace folks during the coldest weather we have had on Whidbey for at least a year. On the weekend.
But the reason for this post is that not only did I get good advice about the problem I also got a lesson in good quality control. The problem with the 17 year old furnace was a bi-metal switch called a "Flame Rollout Sensor". In any case there are two of these switches. They are easy to reset but I was told that if one needs to be reset and there is a flame present then the switch is failing. So I was told to buy two switches because if one failed the other one will fail soon. So I bypassed one switch and the furnace started working again. Two days later the second switch failed. That is some great quality control. After 17 years of operation the switches failed within two days of each other. I am impressed. It's a good thing I took the expert's advice and ordered two switches.
Eric

 

[etpm]

Well, it may be that the rollout sensor switches are working properly. After further research the furnace vent may be obstructed. So the furnace off for now and tomorrow I will be checking the vent. It could be bad switches and great quality control or it could be bad venting or something else.
Eric

 

[old and tired]

One other thing to check, had it happen to me, a leaf got into the intake and blocked enough of the air to not allow enough air to fire up the furnace. Furnace would shut down, leaf would fall down (not block) and depending on our luck, it might lite up the next time... but mostly, it blocked the in take.

This was right before air entering into the unit. easy to remove the rubber boot to connect the PVC pipe to the furnace. Hope it's easy fix for ya... Might not be a bad idea to blow the air intake out from that location.

 

[ray66v]

Roll out sensors don't normally just fail for no reason. Usually, it's because they got over heated.

You may simply be able to reset it, and it will work again. Other times, they get fired.

If you have a high efficiency condensing furnace things can be complicated. It could be the intake, the exhaust, the draft motor, the primary or secondary heat exchanger, or damaged burner(s). All these have to be in good working order for the system to function properly.

I had a junk Carrier furnace that came with the house, which presented a ton of these issues for years, before I ripped it all the way apart, (it's like a heater core replacement, everything has to come out to get to it), to inspect the secondary heat exchanger. As expected, it was clogged up.

Apparently, that particular furnace was fine, when running on natural gas. But, a nightmare if you ran it on propane. They knew it, but didn't care enough to make it right.

I scrapped it, and put in an Armstrong. Much better furnace.

 

[ultrarunner]

The AC coil at the farm was dirty and the furnace would stop… airflow issue.

The filter changed regularly but air could also get around and dust along with enough pet hair built up over 10 years.

After deep clean and a much larger airtight filter box I think we are good.

Proper Airflow is critical on modern furnaces

 

[dodge man]

Before we had geothermal we had wasps building in the intake and the exhaust pipes.