HVAC

Have HVAC questions? Ask an HVAC Expert for answers

Ask an Expert,
Get an Answer ASAP!

I have an unrented mobile home with an oil furnace that

Customer Question
Hello Pearl, I have...

Hello Pearl, I have an unrented mobile home with an oil furnace that burns kerosene. Every fall (now) for the past three years I try to get the furnace to keep the interior around 50f. Same problem every time: furnace will trip the reset many hours after I get it going. This year I set up internet sensors to watch the thing cycle. Last night first frost and I see it cycled three times until midnight and bang it is now 42f in there. Several commercial service attempts with same results every time

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

Filters removed at the moment

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

As long as no one is living there, yes

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

Flame sensor replaces twice, new fuel lines, full tank of fuel.

Submitted: 7 months ago.Category: HVAC
Show More
Show Less
Ask Your Own HVAC Question
Customer reply replied 7 months ago
Flame sense and fuel line were done by commercial service techs. I am being encourage to replace the burner but I see it works and heats while it is running so why replace the whole thing to shotgun it? Is there not a step by step process to find the real problem? Good CO detector nearby, flue seems ok, fan always comes on after a short repeatable delay, always seems to start after pressing reset... ??
Answered in 41 minutes by:
10/1/2017
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago
Rick
Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 24,016
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. First I’ll need some more info so I have a more complete picture of your situation.

Does the burner shut down when it is firing?

Ask Your Own HVAC Question
Customer reply replied 7 months ago
Have never caught it failing while standing there. Part of the frustration :)
Customer reply replied 7 months ago
Have never caught it failing while standing there. Part of the frustration :)
Looking at the duct temperature cycles from last night, I see no partial cycles if that helps.
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

What's the brand and model of the burner? has the ignition transformer spark ever been checked?

Ask Your Own HVAC Question
Customer reply replied 7 months ago
I will check it and reply. Probably an hour or less. Not sure on spark but parts changers have tried several times. Happy to check if you can walk me through it. (Career field service background medical and semiconductor industry)Have never caught it failing while standing there. Part of the frustration :)
Looking at the duct temperature cycles from last night, I see no partial cycles if that helps.
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

TRANSFORMER CHECK

You can check the transformer with a heavy (plastic handle) screwdriver, shut off the oil valve on the pump, swing the transformer/igniter back on its hinge and put the blade of the screwdriver on one terminal of the transformer and hold the tip 1/2" away from the other terminal and hit the reset button. If the arc doesn't jump the gap then the transformer is weak and should be replaced.

Ask Your Own HVAC Question
Customer reply replied 7 months ago
Rick, Becket AF15
Isi or Lsi furnace division of lear
Model cnf80-po
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

Ok, also check electrode gap. Should be 1/8" apart, 1/8" ahead of the face of the nozzle and 7/16" above the centerline. Also check for cracks in electrode porcelain.

Ask Your Own HVAC Question
Customer reply replied 7 months ago
Interesting, this morning it is running only for a brief time them kicking off. I see fire in the view port but not all that long. It ran just long enough for the circulation blower to kick on for a bit. Tries to restart itself and does. Each time runs a bit longer.
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

If the burner shuts down (prematurely) then fires up again on its own with no reset then you have to look at the fan/limit control.

Ask Your Own HVAC Question
Customer reply replied 7 months ago
Ok I have a silver honeywell box with a white plastic manual/auto push pull. That looks to be running off a sensor above the fire box and one leg of the blower power is going through it. How to check? This honeywell Box looks fairly new.
After two initial resets in cold trailer this am for you, this has been staircasing it's growing run time. Now just running.
Yesterday it started on initial reset and ran continously until I left the trailer.
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

You have to check voltage on the burner side of the fan/limit. If it's cutting out while there is a call for heat but before it reaches the hi limit pin then the control is defective. Another possibility is a bad thermostat or thermostat wiring so we always jump out the thermostat at the burner when troubleshooting

Ask Your Own HVAC Question
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

Ok, but all of the above still applies. High limit keep the heat exchanger from overheating.

Ask Your Own HVAC Question
Customer reply replied 7 months ago
A-Springing sound at burner, could that be air in fuel line? Or normal pump noise? I see no flicker in flame to my eye.
B- this time burner stopped but blower still running. Then burner started again before blower shut off. Normal??
C-Ok steps to take:
1- jump tstat during testing
2- with fuel off, knob ccw until it falls off, tip back head and check spark and electrode distances.
3-check voltages on fan/limit.
Did i miss anything?
Does fan high limit normally cycle the burner off on a long heat cycle like warming this freezing trailer back up? Or is it purely emergency shutoff? Curious if we are not moving enough air across the heat exchanger??
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

A) I have no idea what the noise you are describing mght be and no way to tell from here
B) yes, blower will run as long as there is a call for heat once the heat exchanger heats up. Burner will shut down when it reaches limit temp then back on again after blower drops heat exchanger temp
C) yes

Yes limit cycles burner off on a long cycle. It's perfectly normal

Ask Your Own HVAC Question
Customer reply replied 7 months ago
A-Ok inverse question, could one hear air in the fuel line as the pump is running?
B/C- ok sounds normal.
Perhaps the issue is at startup when it sits for a few hours. What will make it trip the reset, forcing a manual reset?
The trailer reaches setpoint and it has not shutdown as expected. I will do breakfast and check back in a few hours. This is exactly what happens. It seems ok but then I find the trailer ice cold and needing another reset.
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

A) no

Lockouts happen with ignition or control failure. Of over looked is the cad cell socket and wiring. You said the cad cell had been replaced, what about the socket?

Ask Your Own HVAC Question
HVAC Technician: Rick, HVAC Supervisor replied 7 months ago

Do you have more questions?

Ask Your Own HVAC Question
Was this answer helpful?
Ask Rick Your Own Question
Rick
Rick
Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 24,016
24,016 Satisfied Customers
Experience: 40+ yrs. experience as a licensed oil & gas technician.

Rick 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

6,938 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

Kenton Guidry

Kenton Guidry

HVAC Technician

963 satisfied customers

12 years install/service experience.

Brian HVAC Guy

Brian HVAC Guy

HVAC Technician

953 satisfied customers

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

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
If I were to choose between an Amana or Trane furnace and central
If I were to choose between an Amana or Trane furnace and central air, which one would be a better more reliable and affordable purchase?… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
I was priced at $4,200 to replace a heat exchanger on our Newmac
I was priced at $4,200 to replace a heat exchanger on our Newmac wood/oil furnace. A hole was discovered by the repairman during a heat efficiency test. They offered a new Airco Rear Flue Low Boy Oil … read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
I have a T164-10-3 low boy the combustion chamber is cracked
I have a T164-10-3 low boy the combustion chamber is cracked and I over loaded it with fuel and I do not want to take the chance on starting it up so I am willing to spend the money on a new one. what… read more
Bill P.
Bill P.
Installer/ Troubleshooter/Technician
286 satisfied customers
Oil furnace blower comes on, no flame or ignition. I buy the
oil furnace blower comes on, no flame or ignition JA: Did you check the furnace's filters? Customer: yes JA: Do you plan on doing the work yourself? Customer: I buy the parts JA: Anything else we shou… read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
My old oil furnace needs rest=ettiung in the mornings, but
My old oil furnace needs rest=ettiung in the mornings, but OK in the day. does the bi metal actuator itself ever need changing as the scavenge time is opnly 45 seconds … read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
How to clean heat exchanger coils, filters have been clean
filters have been clean recently and I am getting an airflow alarm on the thermostat … read more
Gaztech
Gaztech
Technician
Vocational, Technical or Trade School
1,804 satisfied customers
The high temp wire that is wrapped around the heat exchanger
the high temp wire that is wrapped around the heat exchanger is showing no continuity, I get A2 error code … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
My heat exchangers do not function any where near the rated
My heat exchangers do not function any where near the rated BTU output. They were installed three years ago by a professional electrician. The units operate, but you can only tell by putting your hand… read more
F. Naz
F. Naz
CA Finalist & Completed B.com
278 satisfied customers
Oil furnace not hot just added fuel today. Flashing light
oil furnace not hot just added fuel today JA: Did you check the furnace's filters? Customer: flashing light says lockout mode JA: Do you plan on doing the work yourself? Customer: no JA: Anything else… read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
Try trying to Prime my Thermo Pride oil furnace just turned
Try trying to Prime my Thermo Pride oil furnace just turned it on twice bled out some fuel now nothing … read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
I have a Lennox oil furnace and was wondering how I can
I have a Lennox oil furnace and was wondering how I can change the filters. Black smoke is blowing in my house now. … read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
Oil furnace will not turn on message says standby but it
Oil furnace will not turn on message says standby but it doesn't do anything can anyone help… read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
Oil furnace will run if reset but will on run to degree,
oil furnace will run if reset but will on run to 69 degree, even if you have is set thermostat set on 80 degrees. Nozzle has been replaced, oil filter was changed.… read more
Rick
Rick
HVAC Supervisor
24,016 satisfied customers
My reillo burner on my oil furnace wont fire it wont do
Hi, my reillo burner on my oil furnace wont fire it wont do anything when you push the reset button any advice … read more
Phil
Phil
Mechanical Engineer
Degree, Mech Engr Technology
6,938 satisfied customers
58MVP080 model got the heat exchanger issue. I have tech
Hi Pearl,58MVP080 model got the heat exchanger issue … read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
Flashing light on Beckett oil furnace. The pump was seized,
Flashing light on Beckett oil furnace JA: Did you check the furnace's filters? Customer: Yes JA: Do you plan on doing the work yourself? Customer: The pump was seized , I installed a new one JA: Anyth… read more
Gaztech
Gaztech
Technician
Vocational, Technical or Trade School
1,804 satisfied customers
Need a heat exchanger for model GIN 80bu-1000 14B-3A; ser. #
need a heat exchanger for model GIN 80bu-1000 14B-3A; ser. # 1607K 03798 … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
Is it unsafe to have a cracked heat exchange on your
Is it unsafe to have a cracked heat exchange on your furnace? … read more
Rick
Rick
HVAC Supervisor
24,016 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