HVAC

Have HVAC questions? Ask an HVAC Expert for answers

Ask an Expert,
Get an Answer ASAP!

How do I fix a limit switch being open on a furnace model #

Customer Question
How do I fix...

How do I fix a limit switch being open on a furnace model # DLASO75BDD

Contractor's Assistant: Did you check the furnace's filters?

It doesnt have any filters. Its a direct forced air furnace

Contractor's Assistant: Do you plan on doing the work yourself?

Yes if possible

Contractor's Assistant: Anything else we should know to help you best?

Theres a flash code that blilnks 4 times. Says its due to a limit switch being open. Need to know how to close it

Submitted: 1 year ago.Category: HVAC
Show More
Show Less
Ask Your Own HVAC Question
Answered in 2 minutes by:
5/18/2017
HVAC Technician: Rick, HVAC Supervisor replied 1 year ago
Rick
Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 24,383
Experience: 40+ yrs. experience as a licensed oil & gas technician.
Verified

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.

You can try resetting the rollout switch(es) (see attached pic for typical). They are located just outside the burner chamber. Turn off the power then press the small button between the 2 leads to reset it. If it clicks you have reset it and the unit will fire up when you turn the power back on with any luck. If it doesn't click it wasn't tripped.
Check to be sure there isn't more than one by tracing the leads connected to the switch.

Ask Your Own HVAC Question
HVAC Technician: Rick, HVAC Supervisor replied 1 year ago

Do you have more questions?

Ask Your Own HVAC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a hvac technicianLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Phil Your Own Question
Phil
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 7,426
7,426 Satisfied Customers
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial

Phil is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future.

JimmyBagley, IA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Phil

Phil

Mechanical Engineer

7,426 satisfied customers

Retired HVAC/ Electrical & Boiler contractor. Industrial

Rick Mather

Rick Mather

HVAC Technician

3,133 satisfied customers

35 years experience, HVAC

Matthew

Matthew

HVAC Technician

2,014 satisfied customers

14 years experience in the HVAC field of service, installation, Manual J & D calculations

Brian HVAC Guy

Brian HVAC Guy

HVAC Technician

1,019 satisfied customers

I have been an HVAC/R mechanic/technician for 30+ years.

Kenton Guidry

Kenton Guidry

HVAC Technician

963 satisfied customers

12 years install/service experience.

Rick Ridley

Rick Ridley

UK Heating Engineer

871 satisfied customers

Retired But have had 30 years on the tools, Ex CORGI

Tom

Tom

HVAC Technician

770 satisfied customers

16+yrs HVAC/R service. Residential Commerical Industrial

< Previous | Next >

Related HVAC Questions
I too have a York Diamond 80. The heat does not come on. The
I too have a York Diamond 80. The heat does not come on. The thermostat seems to be doing its job. The blower comes on but the heat does not. I checked the pressure switch by blowing into the tube and… read more
Gaztech
Gaztech
Technician
Vocational, Technical or Trade School
1,942 satisfied customers
My furnace won't kick on and it's freezing in here. I just
My furnace won't kick on and it's freezing in here. … read more
type2technician
type2technician
253 satisfied customers
Light flashes 4 times, Open Hihg Limit Switch, Seems every
Seems every year, this furnace has an issue with starting … read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
My furnace continues to blow cool air and I see a red light
My furnace continues to blow cool air and I see a red light flashing 4 times and the panel says open limit. I replaced the limit switch today with a new limit switch and I'm getting the same message. … read more
HvacmanSean
HvacmanSean
Owner
HVAC
233 satisfied customers
I have an XV95v installed in 2009 and it is cycling on and
I have an XV95v installed in 2009 and it is cycling on and off. On for about 10 mins then off for 1 mins then on again. We were gone for a couple of days and set the thermostat at 50... when we came h… read more
Phil
Phil
Mechanical Engineer
7,426 satisfied customers
I have problems w/ a Coleman DGAA 70 gas furnace. Runs fine
I have problems w/ a Coleman DGAA 70 gas furnace. Runs fine for about 3~4 cycles then I get a green flashing light. Reset switch and runs fine for another 3~4 cycles. Help… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
my furnace blower doesnt start even though the burner lights I
my furnace blower doesnt start even though the burner lights I have a flashing LED on the control board. it flashes 4 times after the flame is shut down… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
Hi, our furnace (Trane XE 90) went out last night and am looking for some guidance on gett
Hi, our furnace (Trane XE 90) went out last night and am looking for some guidance on getting it going again. The blower does come on and air is blown out, but theres no heat. The red light is blinkin… read more
theplumber717
theplumber717
Plumber
Vocational, Technical or Trade Scho
791 satisfied customers
MY GAS FURNACE WILL RUN FOR ABOUT 15 MIN. THAN SHUT DOWN.
MY GAS FURNACE WILL RUN FOR ABOUT 15 MIN. THAN SHUT DOWN. THE THEMOSTAT STILL NOT SATISFIED IT WILL NOT KICK IN UNTILL THE POWER IS TURNED OFF AND BACK ON. WE HAVE CHANGED THE CONTROL BOARD,GAS VALVE,… read more
Phil
Phil
Mechanical Engineer
7,426 satisfied customers
Trane xb80 furnace throwing 'open high limit device ' code.
Trane xb80 furnace throwing 'open high limit device ' code. Need assistance due to cold weather this evening!… read more
theplumber717
theplumber717
Plumber
Vocational, Technical or Trade Scho
791 satisfied customers
I have a York Model P3DNB12N08001E. I replaced a flame sensor
I have a York Model P3DNB12N08001E. I replaced a flame sensor today and the two air filters and checked the flue for cleaning. I am getting four red flashes from the error code light. I pulled out my … read more
theplumber717
theplumber717
Plumber
Vocational, Technical or Trade Scho
791 satisfied customers
Just concerned I cannot get this fixed and then I will need
Just concerned I cannot get this fixed and then I will need to call a technician to come to my home anyway… read more
HVAC_Doug
HVAC_Doug
Vocational, Technical or Trade Scho
Power went off in our home for 9 hours saturday. Since coming
Power went off in our home for 9 hours saturday. Since coming back on furnace isnt lighting. Its a goodman gch90904cx. Led flashes 4 times indicating high open limit. I replaced pri***** *****mit swit… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
I have a white-rodgers universal 50A55-843 with diagnostic
I have a white-rodgers universal 50A55-843 with diagnostic indicator flash code 4 open high temp limit switch flashing....the furnace only blows cold air.. I bypassed the limit switch and the burners … read more
V12Tech
V12Tech
252 satisfied customers
i have a lennox g40uh(x) series furnace led 1 is slowly flashing
i have a lennox g40uh(x) series furnace led 1 is slowly flashing led 2 is on it says in the manual- primary or secondary limit switch open. limit must close within three minutes or unit goes into 1 ho… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
I have a Ducane Gas heater - about 10 Years old. The model
I have a Ducane Gas heater - about 10 Years old. The model number is XXXXX We used programmable Thermostat (Honeywell). Currently, the heater is signal error code as follow : 4 flash stop for 2 second… read more
Tim H
Tim H
Lead building engineer
Vocational, Technical or Trade Scho
1,922 satisfied customers
I have an Armstrong Air Ultra SX 80E furnace according to the
I have an Armstrong Air Ultra SX 80E furnace according to the flashing light is says the limit switch is open. I turned the system off, waited a few minutes and restarted the system. Instead of flashi… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
My Goodman furnace is the GMPN forced air gas furnace and has
My Goodman furnace is the GMPN forced air gas furnace and has set for over a year. Had gas turned on, furnace fires but shuts down after two minutes and flashes that the main limiter switch is open. I… read more
John
John
High School or GED
27 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x