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Old 11-12-2011, 02:50 AM   #46
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Is this old Furnace Able to be Serviced?


I hope that the top glass tube turns off the blower fan at the temperture you could once select. This will be confirmed when you watch it's operation with the cover off. It was probably set for 90F when it was new but it now needs to be turned up to 150F to do the same thing because of aging wear. Two minutes is not bad a time delay for the fan to come on but it was probably originally four minutes. The same for when the gas turns off..about a four minute delay. A hand temp test at the registers after the gas valve turns itself off will tell you if the blower is on long enough. If its still hot when the fan shuts off, its costing you in lost heat.

I guess I could of saved me some writing if I asked you why you were not happy with the fan running all the time. You will never have it as efficient, or as evenly distributing the heat as when the fan is running all the time!

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Old 11-12-2011, 09:10 AM   #47
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Is this old Furnace Able to be Serviced?


You can safely set it at 150 deg. I replaced hundreds of those back in the 70s and 80s and would set them at 150. The heat exchanger is literally so thick and heavy that nothing short of a bomb could hurt it. Do the random sampling of CO on different days (cooler, hotter and windy and non-windy) so you get a good representative sample and then you can feel safer.
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Old 11-12-2011, 01:16 PM   #48
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Is this old Furnace Able to be Serviced?


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Originally Posted by how View Post
Two minutes is not bad a time delay for the fan to come on but it was probably originally four minutes. The same for when the gas turns off..about a four minute delay. A hand temp test at the registers after the gas valve turns itself off will tell you if the blower is on long enough. If its still hot when the fan shuts off, its costing you in lost heat.

I guess I could of saved me some writing if I asked you why you were not happy with the fan running all the time. You will never have it as efficient, or as evenly distributing the heat as when the fan is running all the time!
The duration for the time delay that I mentioned last night were guestimates. Today, I put a stop watch on it and noticed that it took 2 minutes 45 secs to start the fan after burner ignition and 5 min 30 sec for the fan to stop after the burner turned off. I gotta get some one to help me see if its still blowing hot at the time when the fan turns off.

I don't under stand how running the fan all the time makes it more efficient, when the fan is running and the burner is off, it is blowing cool air in from the basement. I understand how having the fan run all the time keeps the temperature even but bringing in cold air just after I warmed the house up seeps to very in efficient. Also, on the furnaces I remember from other houses I lived in, I never remember the fan running all the time and besides, it seems like it was just burn out the motor faster by having it run all the time. Who knows...maybe cycling the power to the motor multiple times a day will end up killing it faster.

I may try your suggested experiment with the cover off a little be later this after a Home Depot run while this stuff is still fresh in my head to gain a better understanding of the how this thing works but for now, I'm satisfied with its operation. I think?

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You can safely set it at 150 deg. I replaced hundreds of those back in the 70s and 80s and would set them at 150. The heat exchanger is literally so thick and heavy that nothing short of a bomb could hurt it. Do the random sampling of CO on different days (cooler, hotter and windy and non-windy) so you get a good representative sample and then you can feel safer.
Yuri, what did you replace them with and do you have a suggestion that I could use to replace that old controller? If the exchanger is so thick, do you think its made of cast iron? Once the water patterns change, I will measure the CO again. Yesterday during my test it was cold, wet with little wind. Today its cold cloudy with no wind.
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Old 11-12-2011, 01:39 PM   #49
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Is this old Furnace Able to be Serviced?


L4064 control depending on the insertion length. Some are 5", 8" or 11". It is steel as cast iron is only used in boilers. Too brittle for furnaces. Americanhvacparts.com seems to have a lot of goodies.

http://customer.honeywell.com/Busine...US/Default.htm

Go to homes category then residential combustion then relays and controls then limit controls and then find it. Linking n/w/p today on their site

http://www.americanhvacparts.com/fanandlimit_search.htm

You have to be VERY careful with the new control as it has a jumper between the fan side and the limit side which must be broken off/removed. If not then 120 volts will get shot into ole Betsy's millivolt side and blow her to bits. Once you start fooling around with that old millivolt wiring you may end up with NO heat as it is corroded and difficult to get working in a new control. Need 100% clean bare and TIGHT connections. The new control has push in tabs which are NOT easy to make a millivolt system work with. Is designed mostly for 24volt and 110 volt usage.
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Old 11-12-2011, 03:31 PM   #50
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Is this old Furnace Able to be Serviced?


There are many facters for or against continuous fan over intermitant fan use but mostly the possible effiency gain is with getting to utilize heat that you are paying for that would otherwize be going up your chimney. Simply put,the delays in how long it takes for the fan to turn on is the time that usable heat is going largely un used up your chimney. The same thing occurs with the useable stored heat in your heat exchanger after the fan goes off.
The current time delays for your fan on & off times (at the 150F setting) sound normal for your type of furnace. So you can leave it as it is to get your intermitant use, return the lever to the left for continuous use but although a new combination control will be available at any Hvac supply house, maybe this is a place to leave sleeping dogs alone.
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Old 11-13-2011, 02:40 AM   #51
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Is this old Furnace Able to be Serviced?


Quote:
Originally Posted by how View Post
There are many facters for or against continuous fan over intermitant fan use but mostly the possible effiency gain is with getting to utilize heat that you are paying for that would otherwize be going up your chimney. Simply put,the delays in how long it takes for the fan to turn on is the time that usable heat is going largely un used up your chimney. The same thing occurs with the useable stored heat in your heat exchanger after the fan goes off.
The current time delays for your fan on & off times (at the 150F setting) sound normal for your type of furnace. So you can leave it as it is to get your intermitant use, return the lever to the left for continuous use but although a new combination control will be available at any Hvac supply house, maybe this is a place to leave sleeping dogs alone.
Interesting comments on efficiency of heaters with fan continuous vs intermittent. These are things I never really though of until a week ago. Last month my gas bill was $39 so its not really hurting the pocketbook too much but I don't want to throw money away either. I'll have to experiment with the different scenarios to see what works better. On the 150 setting, does this mean that the air coming from the registers is hotter?

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Originally Posted by yuri View Post
You have to be VERY careful with the new control as it has a jumper between the fan side and the limit side which must be broken off/removed. If not then 120 volts will get shot into ole Betsy's millivolt side and blow her to bits. Once you start fooling around with that old millivolt wiring you may end up with NO heat as it is corroded and difficult to get working in a new control. Need 100% clean bare and TIGHT connections. The new control has push in tabs which are NOT easy to make a millivolt system work with. Is designed mostly for 24volt and 110 volt usage.
I wish I knew a guy like you in my area to perform the upgrade. I think I will just live with things the way they are. I will kick myself if I end up breaking something that seems to be working fine. Winter is just starting and mama is not gonna be happy if I destroy the furnace tinkering around. At least I have this info for reference.
You guys have been very helpful, taught me a few things and helped me to ensure the safety of my family.

Thanks, VC
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Old 11-13-2011, 03:31 AM   #52
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Is this old Furnace Able to be Serviced?


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Originally Posted by biggles View Post
Nice unit.......... any chance getting that black cover off that round controller there that is your fan control and hi limit...picture...want to see the inside.maybe a new stat and we'll keep it simple will give you more consistant cyclying..so you don't have to talk to it.....it's 40F in NYC this morning and the model numbers off that black cover .there should be a adjustable slide bar within there set it up to 150F for now if its not there...just saw the first pix its at 95F go to 150F 2 wire stat is easy to change no service guy needed we'll help http://www.bestbuyheatingandaircondi...gory_Code=T-MV
Hey biggles,

I was checking out thermostats from the link that you posted. They are more expensive than I thought they would be. Do you have a suggestion for a nice programmable unit that will work on my system? Please let me know. Thx, Vc
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Old 11-13-2011, 07:51 AM   #53
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the limit on using a programable stat is most run off 24Vs or what is called a feed back from the heating signal...yada yada...on that just explaining it..why yours is different being a millivolt type.you could use a 24V digital stat with a LED screen on yours,but the addition of a 24V/115V transformer and a 24V relay to isolate that millivolt signal generated from the pilot flame... has to happen with the stat install..check www.Grainger for this stat ...#4YZ38.. and prices i don't see many millivolt programables.....not having a 24V system... batteries will power the stat for millivolt controls limiting your selections...how did you do setting the dial temp control up is the fan cycling off after it heats the place?catch you latter...NOTE if you do purchase a stat anyplace it has to say "for use with a millivolt system" on the box.the type you want is one that has sleep/wake/leave/return #3DG27 settings both with temp and times for those California winters!might consider adding that TR and relay easy ... we can talk you thru it and don't worry you won't blow your place up...consider it..

Last edited by biggles; 11-13-2011 at 08:01 AM.
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Old 11-14-2011, 01:59 AM   #54
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Is this old Furnace Able to be Serviced?


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Originally Posted by biggles View Post
the limit on using a programable stat is most run off 24Vs or what is called a feed back from the heating signal...yada yada...on that just explaining it..why yours is different being a millivolt type.you could use a 24V digital stat with a LED screen on yours,but the addition of a 24V/115V transformer and a 24V relay to isolate that millivolt signal generated from the pilot flame... has to happen with the stat install..check www.Grainger for this stat ...#4YZ38.. and prices i don't see many millivolt programables.....not having a 24V system... batteries will power the stat for millivolt controls limiting your selections...how did you do setting the dial temp control up is the fan cycling off after it heats the place?catch you latter...NOTE if you do purchase a stat anyplace it has to say "for use with a millivolt system" on the box.the type you want is one that has sleep/wake/leave/return #3DG27 settings both with temp and times for those California winters!might consider adding that TR and relay easy ... we can talk you thru it and don't worry you won't blow your place up...consider it..
Thanks for the tip. I'll look into Grainger tomorrow for a programmable millivolt controller.
When I raised the controller temp to 150, my furnace responded well by cycling the fan on and off as the burner turned on.
It was all good for a day or so but i think the axles on the fan or the squirrel cage need a little TLC. I woke this morning to the nasty sound of motor trying to start that could not. I put on my robe, ran down to the basement, removed the cover of the furnace and gave the motor an ever so slight clockwise twist and it began spinning normally. I then changed the thermostat back to its normal setting of continuous fan until I get a chance to clean up the fan and grease the axles. I had a feeling this old fan was not going to like starting and stopping. I think I can handle cleaning the fan, removing the dust and making sure things spin smoothly. I'm just glad Iwas home when this occurred because the motor could have overheated and caused all sorts of bad problems. Thanks again for your assistance and if you know what else I should do to keep my fan running smoothly, please let me know. Thx, VC
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Old 11-14-2011, 08:20 AM   #55
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Is this old Furnace Able to be Serviced?


the motor is the only thing that might take oil...need a new capacitor for the supply fan availible at Granger....cheap fix.have a old toothbrush with the furnace switch off..brush the motor openings front and back of dust....might have to slide that fan section out to clean the squirrel fins if there just dusty no big deal...here's is what a capacitor looks like http://www.bestbuyheatingandaircondi...0vorc ..values stamped on it when you replace it...Mfd=microfarads rating, 2 wires off 2 wires on and mount it..so the constant fan was the lower setting on the fan limits thats good ... work that setting anywhere just below 150F its just making hotter air to satisfy the stat setting...quicker. when the main burner comes on that flame is one constant temp to be used according to the supply fan reaction.

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Old 11-14-2011, 11:24 AM   #56
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Biggies advice is good ( especially for the DIY inclined) but be aware that 90 % of the time you are just putting off a motor change until Christmas or New Years eve.. I never asked you if your two speed motor was direct drive or if you have belts and pulleys.
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Old 11-14-2011, 12:31 PM   #57
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Whoops, Missed a photo and part of my mind. Take the belt off and see if the squrrell cage rotates easily. If it doesn't then blower bearings need to be looked at.
A lot of old motors that have not been serviced regularly will choose to die after being lubricated ( If they have not been oiled in years) or when they get switched from intermitant to continuous use.
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Old 11-14-2011, 01:14 PM   #58
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no problemm there..also the motors as most furnaces are are on the return air side so they usually run some what cool with that return air being pulled in.sure remove the belt and spin the motor sheave/pully then spin the pully for the squirrel cage hear anything??? rumbling and quick sops especially on that motr...then after a normal cycle of heat shut the furnace switch pop the fan cover section.....and put your hnd right on the motor body slightly warm but if you can't keep your hand on it your looking at a motor change out....and if your handy we'll talk you thru that one....
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Old 11-14-2011, 04:18 PM   #59
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Quote:
Originally Posted by biggles View Post
the motor is the only thing that might take oil...need a new capacitor for the supply fan availible at Granger....cheap fix.have a old toothbrush with the furnace switch off..brush the motor openings front and back of dust....might have to slide that fan section out to clean the squirrel fins if there just dusty no big deal...here's is what a capacitor looks like http://www.bestbuyheatingandairconditioning.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=c-370vorc ..values stamped on it when you replace it...Mfd=microfarads rating, 2 wires off 2 wires on and mount it..so the constant fan was the lower setting on the fan limits thats good ... work that setting anywhere just below 150F its just making hotter air to satisfy the stat setting...quicker. when the main burner comes on that flame is one constant temp to be used according to the supply fan reaction.
Hey biggles,

I did not see a capacitor. Where is it located. I clicked the link that you posted but it led to a page that was blank. If you could recheck that link, that would be great. If I can see what the capacitor looks like, I might be able to spot it once I slid the motor and fan assembly forward.

Thx, VC
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Old 11-14-2011, 05:09 PM   #60
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It has no capacitor. Belt drive motors don't. Direct drive do. I would buy a good quality Honeywell Focus Pro tstat at HDepot. A set of batteries can go 2-3 yrs on the better quality tstats. I don't run mine off 24 volts. Not hard to change batteries every 2-3 yrs and the newer ones have a LO BAT indicator. There is no specific millivolt programmable thermostat. The old mercury ones had no heat anticipator for millivolt use vs a heat anticipator for 24v use. You can use the one I told you. When you get a new furnace or heat pump they can run some more wires to the tstat and use it from 24 volts from the furnace but for now I would just use batteries. DO NOT ever use rechargeables as the voltage drops and damages them. Good Energizers is all you need.

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