Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-05-2008, 12:10 PM   #16
Newbie
 
Join Date: Jan 2007
Location: West Michigan
Posts: 10
Share |
Default

Furnace coming on, then going off


little update.... i was monkeying around and took off the cover to my curcuit board and lo and behold it looks as though my roof was leaking into my furnace area and dripped onto the board. We have had a crapload of rain here lately and it looks like it has rusted out some of the contacts on the board. i believe i have probably found my problem. off to fix the roof and order a new board. i don't understand why this hasn't made the self diagnostic light go off though. oh well.

Boulderv7 is offline   Reply With Quote
Old 10-05-2008, 12:23 PM   #17
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Furnace coming on, then going off


Quote:
Originally Posted by Marvin Gardens View Post
Just about any hardware store has them. They are called thermocouples.

Measure the length of the one you have and get one that is close to that. They are all the same with a few rare exceptions.

If you have a multimeter you can actually check to see if it's functioning. But my money is that it is toast and for about $5 you can make sure that isn't it.
FYI....The OP's furnace sounds like it's HSI...in which case it doesn't have a thermocouple, but has a flame sensor.
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Old 10-05-2008, 12:28 PM   #18
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Furnace coming on, then going off


Quote:
Originally Posted by Boulderv7 View Post
little update.... i was monkeying around and took off the cover to my curcuit board and lo and behold it looks as though my roof was leaking into my furnace area and dripped onto the board. We have had a crapload of rain here lately and it looks like it has rusted out some of the contacts on the board. i believe i have probably found my problem. off to fix the roof and order a new board. i don't understand why this hasn't made the self diagnostic light go off though. oh well.
If you think about it...a 'fried' board isn't going to work properly...if it fried some sections that relate to self-diagnosis, it isn't going to be able to flash codes.
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Old 10-05-2008, 12:31 PM   #19
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Default

Furnace coming on, then going off


Quote:
Originally Posted by SD515 View Post
FYI....The OP's furnace sounds like it's HSI...in which case it doesn't have a thermocouple, but has a flame sensor.
I am confused with another poster who has a pilot light that keeps going out.

Guess I am too old to carry on more than one conversation at a time.

"A man's got to know his limitations." Dirty Harry.
Marvin Gardens is offline   Reply With Quote
Old 10-05-2008, 12:33 PM   #20
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Furnace coming on, then going off


Quote:
Originally Posted by Marvin Gardens View Post
Just about any hardware store has them. They are called thermocouples.

Measure the length of the one you have and get one that is close to that. They are all the same with a few rare exceptions.

If you have a multimeter you can actually check to see if it's functioning. But my money is that it is toast and for about $5 you can make sure that isn't it.
Flame sensors are far from being anything like thermo couples. And hardware store do not carry them.

A thermocouple produces a DC current in millivolts that holds open the pilot coil (like a solenoid) so that the main gas valve will energize when the thermostat closes to allow passage of 24v current. When that occurs the main 24v gas valve unseats and allows gas to flow to burners.

A flame sensor send a rectified dc signal to the main board that is measured in micro amps, that MILLIONTHS of an amp.

If sensor is dirty that signal cannot pass to the board resulting in burner shut down.

I can recommend some tech materials if you would like to be brought up to speed on furnace controls.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-05-2008, 12:40 PM   #21
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Default

Furnace coming on, then going off


Quote:
Originally Posted by hvaclover View Post
Flame sensors are far from being anything like thermo couples. And hardware store do not carry them.

A thermocouple produces a DC current in millivolts that holds open the pilot coil (like a solenoid) so that the main gas valve will energize when the thermostat closes to allow passage of 24v current. When that occurs the main 24v gas valve unseats and allows gas to flow to burners.

A flame sensor send a rectified dc signal to the main board that is measured in micro amps, that MILLIONTHS of an amp.

If sensor is dirty that signal cannot pass to the board resulting in burner shut down.

I can recommend some tech materials if you would like to be brought up to speed on furnace controls.
Obviously you didn't read the post my post after that.

Is this an alpha dog thing???
Marvin Gardens is offline   Reply With Quote
Old 10-05-2008, 12:51 PM   #22
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Furnace coming on, then going off


Quote:
Originally Posted by Marvin Gardens View Post
Obviously you didn't read the post my post after that.

Is this an alpha dog thing???
Naw, I either missed it or it got posted while I was typing my response.
Was just trying to be helpful.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-05-2008, 12:54 PM   #23
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Default

Furnace coming on, then going off


Quote:
Originally Posted by hvaclover View Post
Naw, I either missed it or it got posted while I was typing my response.
Was just trying to be helpful.
I appreciate your help. I just got lost in my postings.

I find that more and more as I get older. I am doomed. Every one in my family had dimentia and I am sure I am headed that way which really sucks.
Marvin Gardens is offline   Reply With Quote
Old 10-05-2008, 12:56 PM   #24
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Furnace coming on, then going off


Yeah I just checked the time on your post,, your correction got posted while i was still typing.

I am just too slow on this key board.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-05-2008, 01:00 PM   #25
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Furnace coming on, then going off


Quote:
Originally Posted by Marvin Gardens View Post
I appreciate your help. I just got lost in my postings.

I find that more and more as I get older. I am doomed. Every one in my family had dimentia and I am sure I am headed that way which really sucks.

HA join the club. Last night as iwas cleaning away the dinner plates I put the Vinegar in the frig and the butter in the cup board

Any way no harm intended.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-05-2008, 02:05 PM   #26
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Default

Furnace coming on, then going off


Quote:
Originally Posted by hvaclover View Post
HA join the club. Last night as iwas cleaning away the dinner plates I put the Vinegar in the frig and the butter in the cup board

Any way no harm intended.
My wife watched me as I put the cereal in the fridge and the milk in the cabinet the other day. I never even caught it and she had to point it out to me.

I am guessing that in a few years I will still be thinking that all the new electronic furnaces will have thermocouples.

The really sad part is that no one will be able to tell me otherwise.
Marvin Gardens is offline   Reply With Quote
Old 10-05-2008, 02:17 PM   #27
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Default

Furnace coming on, then going off


There's new med's that alleviate those mild symptoms. You just have to decide if the side effects are worth the memory improvement.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 10-05-2008, 02:44 PM   #28
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Furnace coming on, then going off


Quote:
Originally Posted by Marvin Gardens View Post
I am confused with another poster who has a pilot light that keeps going out.

Guess I am too old to carry on more than one conversation at a time.

"A man's got to know his limitations." Dirty Harry.
I have my share of senior moments at times myself...ain't no thing to worry about. The trick is to limit the number that other people see...lol.
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Old 10-05-2008, 03:46 PM   #29
Member
 
Join Date: Sep 2008
Location: Portland, OR
Posts: 1,186
Default

Furnace coming on, then going off


Quote:
Originally Posted by SD515 View Post
I have my share of senior moments at times myself...ain't no thing to worry about. The trick is to limit the number that other people see...lol.
I am working on that part. I told my wife to get out yesterday.... Just kidding. She keeps me sane and I would crumble after 30 years of marriage.

Currently I am bored and just sitting around between projects. I am answering at least 10 posts a day here and am getting confused as to what post I am responding to.......

Need to simplify....a simple life is good....must smash computer now.....sit in corner and suck thumb with blankey.....
Marvin Gardens is offline   Reply With Quote
Old 10-05-2008, 03:55 PM   #30
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Furnace coming on, then going off


LMAO !! Ok Linus !!

__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Heil Furnace Burner Problem timothyr HVAC 79 02-12-2014 07:01 PM
Add-on Wood furnace billmac HVAC 3 06-18-2008 09:17 PM
Furnace troubles, where's the water coming from... Head Scratcher HVAC 10 03-23-2008 07:40 PM
oil furnace problem Dave80 HVAC 1 01-24-2008 07:53 AM
water coming out of my furnace hmsmc1009 General DIY Discussions 4 07-14-2007 10:53 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.