RV

Have RV questions? Ask an RV mechanic online.

Connect one-on-one with {0} who will answer your question

ciruit board flashes every 3 seconds should blower come on frist…

Customer Question
heat will not come on...
heat will not come on, thermostst on, furnace red light on ciruit board flashes every 3 seconds should blower come on frist
Submitted: 11 years ago.Category: RV
Show More
Show Less
Ask Your Own RV Question
Answered in 8 minutes by:
11/6/2010
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
RV SPECIALIST
RV SPECIALIST, RV Mechanic/Diesel Mechanic
Category: RV
Satisfied Customers: 304
Experience: 22 years Diesel/RV,major engine, Chassis, Appliances, 14 Years Owner of successful Rv service center
Verified
yes blower should come on first. what is your model number of the furnace?make sure the blower wheel is free if it is not let me know sometimes mud dobbers get on the exhaust wheel . let me know we are here to help thnaks greg dinsmore
Ask Your Own RV Question
Customer reply replied 11 years ago
atwood 8535 iv yes blower wheel is free checked voltage to blower motor none
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
when you cycle the furnace on check the voltage at the blower when its trying to light. i am going to give you some diag sheets for your furnace and me and you will fix this
Ask Your Own RV Question
Customer reply replied 11 years ago
i dont here it trying to light only thing that happens is light flashes every 3 seconds
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
this means ign failure and usually the blower will come on and give this code lets take the connection off the board and wait a few seconds and reinstall it. because we should have the blower come on first could be a sail switch stuck but i am loading my shop compter email now and thats where my customer dig sheet is i can get to you
Ask Your Own RV Question
Customer reply replied 11 years ago
i dont here it trying to light only thing that happens is light flashes every 3 seconds i took board out and put it back already same results
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago

so is the fan coming on now???

Ask Your Own RV Question
Customer reply replied 11 years ago
no only light flashes no voltage to fan
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
Tthere are three parts to the ignition system, the control board, the electrode wire, and the electrode assembly..

The fan speed has to be such that enough volume of air is flowing so that the sail switch can sense the air flow and tell the control board it has air airflow.. So it will turn on the gas. At the same time the control board will send high voltage via the electrode wire to the electrode assembly. The voltage seeks a ground between electrode and ground probe and a spark occurs. The spark then ignites the main burner.

If no flame is sensed then the control board performs a lock out turning off the system so lets check the sail switch located in the front plastic housing maybe its stuck and it thinks the blower is running let me know greg
Ask Your Own RV Question
Customer reply replied 11 years ago
checked switch with ohm meter after pulling cover is working
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
switch is opening closing or furnace is working? g
Ask Your Own RV Question
Customer reply replied 11 years ago
switch is opening and closing
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
ok then lets put it back together there .the control board realys the power through it and straight to the fan motor i will look some more at the diag this is a weired one. and we are sure its three steady flashes and then a pause?
Ask Your Own RV Question
Customer reply replied 11 years ago
no flashes 1 time every 3 seconds
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago

my bad i was reading it wrong i beleive we have a high limit switch failure that what this code means .so we need to do the same you did to the sail switch check the ohms on the high limit switch sorry

Ask Your Own RV Question
Customer reply replied 11 years ago
where is high limit switch and is it normal open
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
no should be normaly closed. and i do not have my parts manual at home but theres two places one is behind the burner assmbly in the back of the furnace and the other is behind the blower motor(they monitor the burner housing) here is the wiring diagram if we cant see it right iff then i will go to the shop and get the diag for your furnace greg https://www.rvparts.com/itemNotes/schematics/Atwood/Furnaces/documents/85wiring.pdf
Ask Your Own RV Question
Customer reply replied 11 years ago
if switch is good would circuit board be bad
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
yes but i think the switch has failed
RV SPECIALIST
RV SPECIALIST, RV Mechanic/Diesel Mechanic
Category: RV
Satisfied Customers: 304
Experience: 22 years Diesel/RV,major engine, Chassis, Appliances, 14 Years Owner of successful Rv service center
Verified
RV SPECIALIST and 87 other RV Specialists are ready to help you
Ask your own question now
Customer reply replied 11 years ago
checked 2 white wires coming out of housing switch checks good
RV Mechanic: RV SPECIALIST, RV Mechanic/Diesel Mechanic replied 11 years ago
the wires will have to be off the switch to check the ohms did you do that just checking thanks greg
Ask Your Own RV Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a rv mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask RV SPECIALIST Your Own Question
RV SPECIALIST
RV SPECIALIST
RV SPECIALIST, RV Mechanic/Diesel Mechanic
Category: RV
Satisfied Customers: 304
304 Satisfied Customers
Experience: 22 years Diesel/RV,major engine, Chassis, Appliances, 14 Years Owner of successful Rv service center

RV SPECIALIST is online now

Related RV Questions
I have a 8500 furnace that shows a limit issue by the
I have a 8500 furnace that shows a limit issue by the flashing light, how6have check both limits, light is not always flashing when I move the connecting plug I will light but not all the time, do the… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
Dometic DF furnace won't heat. I can start blower manually
dometic DF furnace won't heat. I can start blower manually by turning switch of unit off then on again. I had switched propane tank to new full tank … read more
Nachum Wagschal
Nachum Wagschal
3,168 satisfied customers
I have an atwood furnace. The circuit board was not working.
I have an atwood furnace. The circuit board was not working. I replaced it and the blower would not come on. The circuit board has a green light that comes on when I turn on the thermostat but the blo… read more
Nachum Wagschal
Nachum Wagschal
3,168 satisfied customers
Model 7916 11 stopped lighting, then afterv20 trys it lit,
Model 7916 11 stopped lighting, then afterv20 trys it lit, then the next day, won't light. … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
I own an Alfa See Ya 2002 Atwood 8940-III-dclp furnace isn't
I own an Alfa See Ya 2002 Atwood 8940-III-dclp furnace isn't working ,the red light on the furnace circuit board flashes every couple seconds.… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
8940-III-DCLP furnace starts the first time but after it
8940-III-DCLP furnace starts the first time but after it satisfies the Tstat as the motor home cools down the blower kicks on but furnace won't relight … read more
Wayne
Wayne
RV Mechanic
Vocational, Technical or Trade Scho
2,163 satisfied customers
I turned on my furnace in my 2019 Keystone Cougar 5th wheel.
I turned on my furnace in my 2019 Keystone Cougar 5th wheel. The furnace ignites, blower engages and blows heat for about 2 minutes then it shuts down. There is an audible alarm coming from the furnac… read more
Chris (aka-Moose)
Chris (aka-Moose)
RV Mechanic
2,418 satisfied customers
We have a new 2020 16ft Bambi. Heater is not working. When
We have a new 2020 16ft Bambi. Heater is not working. When thermostat is turned on and heat set to any range fan comes on but no heat. After 60 seconds it shuts off. … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
I have a Atwood 8525 IV When I turn the thermostat to heat
I have a Atwood 8525 IV When I turn the thermostat to heat and the thermostat up the blower willl not kick on it doesn't do anything … read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
We ran out of propane last night, and we just hooked up two
We ran out of propane last night, and we just hooked up two freshly filled bottles. Furnace will not light. I get a signal meaning air flow/limit fault. Have turned outside furnace switch off, then ba… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
My Atwood furnace lights, runs, heats to temp, shuts off.
My Atwood furnace lights, runs, heats to temp, shuts off. But as temp drops it will no restart. When I turn the electronic furnace off and then on, it starts and runs, but when it shuts off it will no… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
I have a 2003 42' Hy-Line park model, with an 8500-IV hydro
I have a 2003 42' Hy-Line park model, with an 8500-IV hydro flame furnace. when I attempt to turn on the furnace I get a clicking sound, click at 1/2 second intervals. I removed the furnace and had it… read more
Randall
Randall
RVIA Certification
Vocational, Technical or Trade Scho
26,243 satisfied customers
I have a 2006 fleetwod camper with a Atwood 7900 series
I have a 2006 fleetwod camper with a Atwood 7900 series furnace that will not turn on. I replaced the limit switch which was what the owners manual suggested. The red light on circuit board flashes on… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
My furnace won't start. the red light on circuit board is
my furnace won't start. the red light on circuit board is flashing every 3 seconds or so...any ideas on what is wrong??… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
I have a Shasta travel trailer with an Atwood furnace, model
I have a Shasta travel trailer with an Atwood furnace, model 7920-11. It fires up fine the first time when the thermostat "tells it to", heats up the trailer to the thermostat setting, shuts off as it… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
We have a 1996 Fleetwood Prowler that had a Coleman AC and
We have a 1996 Fleetwood Prowler that had a Coleman AC and Thermostat and a Atwood Furnace/Fridge/water heater. We just had the AC replaced by a RV service center. They installed a Dometic AC and Ther… read more
Robert
Robert
RV Tech Support
Vocational, Technical or Trade Scho
22,947 satisfied customers
Hi Michael I have an Atwood 8940 furnace. The LP and battery
Hi Michael I have an Atwood 8940 furnace. The LP and battery are good. I turn on the unit and the blower runs for about 15 to 20 seconds then shuts off. The RED light keeps flashing about every 2-3 se… read more
spankyjr1
spankyjr1
Retired
Vocational, Technical or Trade Scho
420 satisfied customers
We have a 8500_lv Atwood heater in our motor home and the blower
We have a 8500_lv Atwood heater in our motor home and the blower will kick pn and then the gas burnrt will ignite and run fot about 30 secondd and go off. Then come back on and go back off and this is… read more
iflysi77
iflysi77
100 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.

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:

Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV.

DutchUSA

Highly recommend this RV expert. Prompt, good and detailed answers were given. Very willing to help with genuine concern. I will ask for him next time.

JackUSA

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

< Previous | Next >

Meet the Experts:

gene

gene

RV Mechanic

1,100 satisfied customers

28 yrs exp in the industry

Nick

Nick

RVIA Certification

664 satisfied customers

5 years RV repair and reconstruction, Fleetwood RV Training course completion.

Steve F.

Steve F.

RVIA Certification

443 satisfied customers

Journeyman and Master RV technician, Mechanical & Aerospace Engineer. RVIA Technical Consultant

Randall

Randall

RVIA Certification

26,243 satisfied customers

RVDA/RVIA Master Certified Technician with many years experience.

Chris (aka-Moose)

Chris (aka-Moose)

RV Mechanic

2,418 satisfied customers

24 years of experience diagnosing & repairing

Wayne

Wayne

RV Mechanic

2,163 satisfied customers

Work on several type of Rv engine, Trans, brakes

D. Wood

D. Wood

RV Parts Store Owner

205 satisfied customers

Slide Out, Jack & Hitch Specialist

< Previous | Next >

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