I suspect that the last time a technician repaired the furnace (replaced the ignition module with a White Rodgers 50E47-843) that some things were not set up correctly.

As soon as there is a call for heat from the thermostat, the blower turns on and about 30 seconds later the vent exhaust fan turns on.

At the 60 second mark the igniter heats up and appears to be at full brightness in about 5 seconds but stays on for a full 45 seconds before the gas kicks in (the time the igniter stays on I am pretty sure can be rectified by getting the correct code chip for the controller).

The furnace runs fine until (and excuse my lack of terminology here) it hits the low limit temperature, then in locks out as though it has hit the high limit temperature and won't kick back in until it hits the lower low limit temperature (the one that shuts the blower off after all the residual heat is gone from the furnace).

It almost seems like all the limits have been shifted over by 1, the controller thinks the low limit is the high limit, the minimum temperature for the blower to be on is the low limit and the status as soon as you call for heat where the blower should be off is the minimum blower on temp.

Anyone have any obvious ideas about whether this seems like a wiring issue or a flaked out controller?

Furnace info: https://lh3.googleusercontent.com/-Y...330_124237.jpg

Controller: https://lh5.googleusercontent.com/-s...330_123209.jpg

 

The card in the controller is D (violet) which is listed in the manual as a 45 second ignitor warmup:

https://lh5.googleusercontent.com/-J...330_123253.jpg

It looks like F (yellow) is the card that should be in there to reduce the warmup to 17 seconds:
http://www.emersonclimate.com/Docume.../0037-6426.pdf

 

Welcome to the forums.

I'm not familiar with Olsen furnaces although they use many of the same parts that others use. In the servicing info for your unit would be listed the igniter warmup time and prepurge time.

In your picture I see a Honeywell fan/limit control box. Has that wiring been changed ?

 

There is certainly more wrong than just the ignition timing card. The blower should not come on as soon as there is a call for heat. It almost sounds like someone reversed the venter & blower wiring. Can you supply a wiring diagram for the furnace? They are often located on the inside of the blower compartment door.

 

Wiring diagram:
Diagram

Apparently I also have to make sure the post is more than 25 characters.

 

I have been the owner since '97 and the limit control box has never been changed under my watch, always possible in the first 7 years though.