HVAC

Have HVAC Questions? Ask an HVAC Expert for Answers

Ask an Expert,
Get an Answer ASAP!

HVAC

I have a 1987-ish Rheem 80 plus downdraft that shuts off

Customer Question
Hello. I have a 1987-ish...
Hello. I have a 1987-ish Rheem 80 plus downdraft that shuts off right when the fan starts. I swapped out the ignition control module, flame sensor, and limit switch with no changes. What is left that it could be? I noticed that some of the brass bars across the burners are melted or deteriorated. Could this be related?
Submitted: 2 years ago.Category: HVAC
Show More
Show Less
Ask Your Own HVAC Question
Answered in 1 minute by:
12/16/2015
HVAC Technician: airheatman, HVAC Technician replied 2 years ago
airheatman
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8,808
Experience: Furnace, A/C and heat pump specialist.
Verified

Can attach a photo of these bars?

If you have a paper clip icon on your page you can attach using that link.Or

You can upload the pictures using the tiny pic site .

Here is a link to the site.

http://tinypic.com/

Click on Browse , select the file from your folder.then click UPLOAD NOW.

They will give you a quote to enter in the box to verify you are a human.Enter the quote and click UPLOAD NOW

You will see your picture on right side of screen.

Then copy the link URL for email & IM

Paste that link here on the site.

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Sent a video via tinypic. Not with the unit togetclose-up, but they are visible suspended over each burner ribbon, two on each burner held on with press-on nuts, one that burned through is missing.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

Do not see video yet.

Ask Your Own HVAC Question
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

copy the link URL for email & IM

Paste that link here on the site

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Could not get the video to you by either method. I'm not with the unit, but i'll try to draw it up and send that.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

OK. Also let me ask this, When blower starts is there any dancing or fluxuation in burner flame ?

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Goes out simultaneously with a click and then a puff sound. Blower doesnt get up to speed until after.
Customer reply replied 2 years ago
Oops. Rotate it 90° left
Customer reply replied 2 years ago
onthe honeywell, but without the center red/yellow connections
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

Picture looks like lo nox burners that were installed in units in California and areas requiring them. I do not think they would effect the blower shutting off.

Ask Your Own HVAC Question
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

I am in Alabama and never actually seen them on a furnace and am not familiar with exactly how they work.Do they have wires attached ? D not see them on the wiring diagram

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Nope. No visible means of connection. Silly california.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

I do not think that is your issue personally.

I am suspecting there is an issue with the limit that controls the blower.Does the dial rotate as burners get hot and if so how far on dial are we getting before shutdown?

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Uh oh. I won't be with it until 5pm PST, but from memory, it did in fact rotate,but only to the fan on point. No changes to this after i put the new fan limit on.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

Ok from here it will get a bit more technical. The gas valve gets its signal from one of those relays. It sounds like the relay is cutting voltage to valve when it signals blower on.To start checking voltage , we need first to get correct wiring diagram. Look at link below and tell me which of the ignitions you have.

Ask Your Own HVAC Question
Customer reply replied 2 years ago
The robertshaw
Customer reply replied 2 years ago
Ok thank you. i can check for voltage when i get home. On that diagram, where would i check?
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

I highlighted to wires from control to valve.Check between them. The limit wires are highlighted black. We should have 24v at limit as marked with black wires.

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Ok sir thanks much. I will reply tonight and go from there.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

Sounds good

Ask Your Own HVAC Question
Customer reply replied 2 years ago
The voltage between the yellow and orange wire from ignition control to the gas valve (same as yellow/red wires shown on diagram) shows 24.5 (at the valve) from the time the igniter starts up until the fan starts. Then it chops off to 00.0, and the burner goes out within about a second. If I pull the white manual fan run switch at any given time, the igniter and gas will go out the same way as auto mode. Basically, both will not run at the same time.As for the voltage on the black wires at the fan limit, I am not sure where exactly to take the reading from.
Customer reply replied 2 years ago
Excellent. Do you happen to recognize these particular relays and maybe their part number?
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

http://www.amazon.com/42-19423-01-Rheem-Aftermarket-Replacement-Relay/dp/B00FXYDHSK

http://www.amazon.com/Rheem-421828712-Division-42-18287-12-Relay/dp/B00GNUER50

Not sure these will solve the issue, but definitely seems we have a relay that is cutting out burners and as stated you have already replaced fan limit and module, so for the price, worth a shot.

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Thank you. Got the 19423 coming. That one would figure into this well, because when it went down initially, it would not do anything at all until I was looking for loose connections and tapped on it. I'll switch that one first. Thanks very much.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

Hopefully this will solve the issue.

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Hello again sir. I hope the holidays were good to you. Well, eventually, I was able to get those relays here and installed. Neither resulted in any change. While looking around for obvious issues i may have missed, i noticed that after I plug the furnace in to power, something within the cooling unit below the furnace makes a faint, irregular clicking noise for about one minute and then trails off to silent. If I call for heat before it stops clicking, the relay(s) clatter in time with the faint clicking. Not sure if this rings a bell. The other thing i noticed is the fan center kunction box had a few loose wire nuts. One red fan wire came out separately as i was trying to organize things in there, so i had to look at the diagram and put it where it belongs, but nothing has changed. The gas valve kicks off immediately any time the main blower is switched on, whether manually or auto. Any ideas on where to go from here?
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

Lets look at the pressure switch next.Silver canister on left with orange rubber hose going to it.

Disconnect hose from vent motor and leave attached to switch.Call for heat,and allow vent motor to start.Then suck on hose and keep a vaccum on hose until burners light and blower starts and see if burners will stay on as long as you are sucking n hose.

Ask Your Own HVAC Question
Customer reply replied 2 years ago
It still shuts off the gas valve when the blower motor starts.
HVAC Technician: airheatman, HVAC Technician replied 2 years ago

I will open to see if other experts have any ideas

Ask Your Own HVAC Question
Customer reply replied 2 years ago
Hello sir. Just checking to see if there still exists a liklihood of any further ideas on this one. Many thanks, Mark
Ask Phil Your Own Question
Phil
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6,938
6,938 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

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
I cannot find ANY installation videos that match my
Hi....I cannot find ANY installation videos that match my Honeywell RTH22B thermostat that I just bought. I don't understand how to get the wires into the black part … read more
David Bowden
David Bowden
Owner
473 satisfied customers
My Ruud water heater is leaking from the pressure valve on
My Ruud water heater is leaking from the pressure valve on top of the tank. The power is off. Earlier I flushed the tank, but not very good. Now when I turn on the main water valve to the tank I notic… read more
airheatman
airheatman
HVAC Technician
8,808 satisfied customers
I have a 394gaw furnace the main burners light, stay lit for
I have a Bryant 394gaw furnace the main burners light, stay lit for 30 seconds then go out the pilot stays lit the whole time … read more
Phil
Phil
Mechanical Engineer
6,938 satisfied customers
No power to themostat. Breakers ok. Fuse OK with FAU in
No power to themostat. Breakers ok. Fuse OK with FAU in attic. Could problem be at A/C condenser located outside? Is there fuse located with Condenser outside that could be blown causing the thermstat… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
I have a Rheem Classic Super Quiet 80 that just stopped
I have a Rheem Classic Super Quiet 80 that just stopped heating our house this am. We had 40mph gusts today and I suspect they blew the pilot light out.… read more
airheatman
airheatman
HVAC Technician
8,808 satisfied customers
My problem is with an old amana central heater i cleaned the
hello my problem is with an old amana central heater i cleaned the sensor and replaced the H.S. igniter it heats up when turned on but doesn't ignite then it turns off. the fan continues to blow. … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I need a replacement gas valve for model 7656f859. I am a
I am a gas service tech who trouble shot the unit last week. … read more
airheatman
airheatman
HVAC Technician
8,808 satisfied customers
MY lennox elite series model C26-41FC-1 blower will not
MY lennox elite series model C26-41FC-1 blower will not engage … read more
Gaztech
Gaztech
Technician
Vocational, Technical or Trade School
1,142 satisfied customers
I've recently installed a HM700A1000 steam humidifier and
I've recently installed a HM700A1000 steam humidifier and everything is working fine except that it's not shutting off. It has the yellow LED constantly on which indicates the water level is to high w… read more
airheatman
airheatman
HVAC Technician
8,808 satisfied customers
I have a Honeywell he 311 and it keeps going off the purge
I have a Honeywell he 311 and it keeps going off the purge light stays on for a few then off and the machine never goes on … read more
Phil
Phil
Mechanical Engineer
6,938 satisfied customers
Have a carrier thermostat. Fan is working. However I'm
Have a carrier thermostat. Fan is working. However I'm unable to set a temperature and the heat won't come on. Has an error saying HP … read more
Phil
Phil
Mechanical Engineer
6,938 satisfied customers
Trying to add Aprilaire 600M to Lennox furnace with iComfort
Trying to add Aprilaire 600M to Lennox furnace with iComfort tstat. … read more
Phil
Phil
Mechanical Engineer
6,938 satisfied customers
Yesterday we completed installing a Goodman 60,000 BTU
Yesterday we completed installing a Goodman 60,000 BTU 80%eff furnace, brand new or if the package. It fired right up. Turned it off for the night after turning up to 80 to get s blast of heat before … read more
Phil
Phil
Mechanical Engineer
6,938 satisfied customers
I recently bought a property that has a programmable
This is ***** *****. I recently bought a property that has a white rogers programmable thermostat, and I don't know how to operate it. It is a 1F81-261. Do you have instructions? … read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
How to install the Rinnai direct vent wall furnace. I.
how to install the Rinnai direct vent wall furnace … read more
Gaztech
Gaztech
Technician
Vocational, Technical or Trade School
1,142 satisfied customers
I have a TH8000 Series programmable thermostat now. The
I have a TH8000 Series programmable thermostat now. The clock is all wrong. I'm thinking of a wiFi programmable thermostat. but having a problem with what is compatable. can you advise? Thanks Jerry … read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
Installed new Goodman split heat pump outdoor unit runs even
Installed new Goodman split heat pump outdoor unit runs even with all low voltage disconnected … read more
Iohn Keffer
Iohn Keffer
HVAC Tech
Associate Degree
41 satisfied customers
Well j, Well just replaced a motor, No never dealt with you
Well j JA: I'll do all I can to help. How long have you been dealing with this? Customer: Well just replaced a motor JA: Do you plan on doing the work yourself? Customer: No never dealt with you befor… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 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