Hi, I have a York furnace and I am having problems with it staying on. The warning message I get is a red light blinking 4 times, Limit switch open. What does that mean? Any suggestions?

https://fireplacehubs.com/york-furnace-red-light-blinking-7-times/

https://upgradedhome.com/york-furnace-red-light-is-blinking/

Witch blower is running, the inducer or the systems blower?
System blower could mean the the high limit is opening and shutting down the systems gas train, I would check this out first.

The other problem could be with the pressure switch for the gas train, it is supplied from the inducer motor, check to see if it is operating fully.

HSI boards do go from time to time, this sounds more like a system control problem.

your ventor motor has to come on first to close limit switch,follow tubing from switch to ventor motor see iffu have 120 volts going to it, if 120 volts replace ventor motor assembley, no reset on board, board will reset every time u turn of power and back on

Gas furnace fault or error codes for common furnaces - Gray ...

www.grayfurnaceman.com/-ifc-failure-codes.html
Each color will also flash a specific number of times to signify a specific error. ... 4 redcolored flashes may be signaling that the "high-limit" switch might be open. ... 3 green colored flashes on your furnace has the same meaning as 2 green colored flashes. ....If a system problem occurs, a blinking LED shows a fault code.Missing: xenon

7 Tips and Tricks to repair your Furnace DIY - YouTube

? 13:25
https://www.youtube.com/watch?v=rAtcvPqUsBA
Dec 18, 2012 - Uploaded by JRESHOW .
Flash sequence codes 1 through 11 are as follows: LED will turn "on" ... 4 RED FLASHES: This indicates that the main limit switchhas opened ... This no-light condition occurred 3 times (2 retries) during .... My furnace trane xe80 is only flashing once my manual says something about flame being locked out ...Missing: xenon ‎efficiency

You'll need to replace the fan limit switch. This little switch is what tells your blower when to kick on and when to shut off. It's stuck open.

Hi,
Check on the back of the bottom blower cover...I think it is either pressure switch or high limit...

But the codes are always listed on that bottom cover on the inside...

Here is a tip that will help you try to figure out why your furnace is not working.

Basic Furnace or Heating System Troubleshooting

heatman101

Try the heat limit switch it could be stuck open take it out and clean the back off it

Hi,
One of the limit switch in the furnace is tripped or went bad....
Try to find all of the reset switches and push the little red button on the top to reset them...
If that don't work you will need to take an electric meter and test each switch to see which one is bad...

heatman101

how can I fix the spill limit switch, also how do I found it

There may be more than 1 limit switch. Look at the wiring diagram and follow it to all switches. Or jump out the complete circuit.