Model GCI115X35A/P1155313F - There is a Manual Reset Limit Switch mounted on the blower housing, what will be the effect if I push it in?, what is its purpose? I’ve included the schematic if it helps, hoping it can be zoomed for viewing. Thank you
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Attachment to WhiteRam’s Amana 80 question.

 

Welcome to the forums.

Usually you start off by asking about a problem.

I see two manually resettable limit controls in that furnace. One is called the Primary rollout limit. This one is usually just above the burner and will trip when the burner (flame) is out of control and is spilling out of the burner chamber. If this one trips..... get service.

The other switch is called Aux limit control. If this one opens..... it cuts all 24v power to the control board. I don't know exactly where that switch is located so I'm not 100% sure what it's protecting. It could be plenum temp. Typically only the flame rollout switches are manually resettable and the high heat limits are auto reset.

They may have converted that furnace to manual reset for a reason.
Overheating is a problem that needs to be addressed.

Possible service manual

 

Thank you, and for having me PJ. Yes I’ve been working on a problem.. furnace makes a fast clickclickclick sound and shuts gas off, blower fan stays running while the fan inducer motor recycles (off for 5s then back on) igniter glows up, furnace fires and continues to work.. this will happen every 5m until thermostat setting is achieved - this happens about 1 out of 3 times, the other 2 times furnace runs from start to finish with no problem. Here’s what I’ve done and checked so far: Replaced flame sensor, replaced high limit switch. Flue, filter, intake & registers are all clean, plenum has no measurable soot. New high limit switch put in 3 days ago, 2 days before that the blower fan started ending its last cycle (blowing the last warm air out of entire system) about 45s sooner than it used too and this did not change after installing new high limit switch. Yes it may have an overheating problem, but I’m starting to think something is giving a ‘false reading’ of it overheating when it’s actually not.

 

That could be a thermostat problem. Set the thermostat to OFF.
Jumper from R to W1 at the control board and see if the system still cycles.

 

ps. Furnace has 5 jets producing flame into the burner, across the base (starting point) of these 5 jets.. there is a line of flame connecting across all the jets, is this normal?

 

There are crossover ports so that one burner lights the next burner in line.
Usually the igniter lights the burner at one end and the flame sense rod is at the other end.
This is to check for all burners to light.

Pictures are always helpful..... How-to-insert-pictures.

 

It was the Limit Switch in the heat exchanger, it was opening at 180F degrees which was the hottest the air ever achieved in the exchanger, this Limit Switch is isn’t supposed to open until 230F. It was the furnace’s original switch made in 1988. I’ve ordered an OEM replacement but it’s rating is 220F, I think it’ll be fine, pic attached is the original. Thank you

 

L230-40F - specifications:
Cut in temp: 190°F
Cut out temp: 230°F
Differential: 40°F

L220 will be ok.