Gas and Oil Home Heating Furnaces - Bard Furnace Heat OK but Fan Wont Turn Off

Just got in an older home and the furnace isnt cooperating.

It is a Bard H1068 Gas Fired Forced Air Furnace.

It reaches the temp - 68F and the heat turns off but the fan continues to run forcing out cool air. I have to manually turn off/on the switch.

It is connected to an Aprilaire Model 110 - 112. I have manuals for both but nothing there.

The thermostat is set to heat and the Fan set to Auto.

:wall: Are there any other settings I should be aware of anywhere? This is the first home and first furnace so a real Newbie here!

thanks for any suggestions,
frank

So recently of getting the house that maybe you can hit up the ex-owner of the house for repair bill, due to non-disclosure, maybe?

Does this furnace have a fan timer board on it? Does it have adjustable settings? Or it is defective on the board.

Or you have a fan/limit control instead, that operates off heat, rather than a timer, and the setting is such on the fan control that the off setting is less than roomtemp setting (it be odd to be that low, but worth looking into). And even if it isn't that, the fan switch may be shot, and the contacts inside for the "off-fan" position are shot, as a logical guess.

Another possibility:Could there be a coincidence where the furnace happens to high limit about the time the temp reaches set point?, so then the fan stays running due to high limit?

So recently of getting the house that maybe you can hit up the ex-owner of the house for repair bill, due to non-disclosure, maybe?

We helped out an elderly woman, who was moved to her daughters state when she became too ill. We took care of the house for four years and then we were offered the house at a very, very reasonable price. About half of what would be considered a great deal... Of course, it was sold "as is" so we dont mind spending a bit more to get a few things fixed up.


Does this furnace have a fan timer board on it? Does it have adjustable settings? Or it is defective on the board.

I have NO idea what youre talking about. If it does have a fan timer board where would I find it and what does it look like = or is it too complex to ask since I am asking?

Or you have a fan/limit control instead, that operates off heat, rather than a timer, and the setting is such on the fan control that the off setting is less than roomtemp setting (it be odd to be that low, but worth looking into). And even if it isn't that, the fan switch may be shot, and the contacts inside for the "off-fan" position are shot, as a logical guess.

Again, I have NO idea what youre talking about.

Another possibility:Could there be a coincidence where the furnace happens to high limit about the time the temp reaches set point?, so then the fan stays running due to high limit?

See above...

Anyways, thanks so much for responding,
frank

I am not too familiar with the bard except for their unit that is mounted to the outside of trailers but if this system is very old it probably has a fan/limit control to control fan operation in heat this is a bi-metal coil mounted in the airstream that turns on and off when the air reaches a set temp if this is the control system you will be able to find it above the burners mounted to the firewall if not then you may have a control board with an integral relay and it sounds like the relay in the board may be stuck

I agree. Mike n put it short and succinct.

Try to trace back perhaps a black wire coming from your main house blower fan, to see what kind of device it goes to. That should be the fan/limit device. Then describe it. Is it some flat board that has terminals on it?, or is it more like a 2 x4 inch metal box that has a cover on it that can be removed with a temperature dial inside, with numbes on it/?Then we can go from there.

This is likely an H106S nt an H1068. Please confirm.

If so, this a very old unit. But they came in two models, one with a standing pilot an another with an intermittent pilot. Which one do you have? Do you have a pilot flame that is ON 24/7 all year-round? or do you have one that lights-up after some clicking and sparking?

This could be something as simple as the "manual" push button of the fan-limit switch having been accidentally pushed in, hence turning the blower ON.

A pic or two of your unit with the service/blower door removed (so as to allow us to see the controls) would go a long way in helping you out.

I agree. Mike n put it short and succinct.

Try to trace back perhaps a black wire coming from your main house blower fan, to see what kind of device it goes to. That should be the fan/limit device. Then describe it. Is it some flat board that has terminals on it?, or is it more like a 2 x4 inch metal box that has a cover on it that can be removed with a temperature dial inside, with numbes on it/?Then we can go from there.

thank you all for being so patient with me...

Yes, Mike n put it exactly right but not in terms that I could really understand but with ecman51 I was able to find the fan limit device. It doesnt have a cover on it but is about 2 x 4 with a temp dial. The fan limit dial is set to 50 - 60 at the very lowest level. The range goes from 50 - 250. I moved it a little but was nervous to mess without any further instructions.

That box has a red & yellow thick wires at the top of the box and a black wire at the bottom. They all go into another box. Then the red and a white wire comes out that box down into a "SPLIT PHASE" motor.

Is the fan limit dial set too low or not functioning?

I have a appliance guy coming over. He was suppose to come yesterday but didnt. then he was suppose to come today but changed to tomorrow.

Would be nice to know that it is just a bad dial setting (fingers crossed)

again, thanks for any help,
frank

YES...that lower setpoint of 50-60 is way too low. It means that your blower will keep on running until the air temperature drops below it...which will never happen. Move it up to about 70-80. Move the middle one to about 100 and the high one to 180.

You should have 3 pins there.
The lowest one is the FAN-OFF setting
The middle one is the FAN-ON setting, and
The highest one is the HIGH LIMIT setpoint

pflor, Yes, I believe you are correct on the H106S (it is stamped in but not very clear).

The pilot is a standing (on 24/7).

It looks like this site pic posting needs a host site. I havent set one up but could do with a recomendation, please...

I dont see a push button.

OK, after reading thru your second response I was mistaken. I didnt notice the pin settings. It looks like the first pin was set around 100+ so I put it at 70-80. I also put the others at your recommended settings.

I guess it makes sense the other way around too as if it was set too high and I have the thermostat set for 70 then it would cut off the heat but the fan keeps running because it never reaches 90-100 (old setting).

I dont really like it very hot and have the thermostat set to 68. Is that 70 - 80 setting going to work with the thermostat at 68?

thanks again,
hoping this solved it... but let me know if pics are needed and hosting site?

frank

OK, after reading thru your second response I was mistaken. I didnt notice the pin settings. It looks like the first pin was set around 100+ so I put it at 70-80. I also put the others at your recommended settings.

I guess it makes sense the other way around too as if it was set too high and I have the thermostat set for 70 then it would cut off the heat but the fan keeps running because it never reaches 90-100 (old setting).

I dont really like it very hot and have the thermostat set to 68. Is that 70 - 80 setting going to work with the thermostat at 68?

thanks again,
hoping this solved it... but let me know if pics are needed and hosting site?

frank

The way the fan-limit switch works (under normal circumstances) is: on a call for heat from the t-stat, only the burners kick ON at first. With the blower not running but a live flame in the belly of the beast :), temperatures rise quickly...after a few seconds of this, the dial of the fan-limit switch starts spinning clock-wise and when the air temperature inside the furnace reaches the middle-pin setting, the fan kicks ON (no wonder is called the FAN-ON setting). If the fan were defective and would not turn itself ON, the temperature inside the furnace would keep on rising and the dial of the fan-limit switch would keep on spinning until it reaches the highest pin setpoint, which will cause the burners to stop firing.

At any rate, under normal conditions again, once the t-stat says "no more heat", the flames cease but the blower keeps on running...and the dial is now spinning on the opposite direction. Once the temperature inside the furnace reaches the setpoint of the lowest pin, the blower stops (that's why it's called the FAN-OFF setpoint).

Please tell me the model number of that fan-limit switch...this is the one with the dial. It's likely a Honeywell, and the M/N should read: L4064-_ _ _ _ I need to know what the last four digits are.

Some of these devices have a little button with a label reading MANUAL-FAN, which if pushed-in will turn the blower ON continuously. Other variation of the same devices have an internal heating element, which could have gone defective and is causing the fan to stay ON. Or the switch could just plain simply have gone belly-up and you need a new one. Knowing its full M/N will allow me to make the right diagnosis.

That box has a red & yellow thick wires at the top of the box and a black wire at the bottom. They all go into another box. Then the red and a white wire comes out that box down into a "SPLIT PHASE" motor.



Inside the box (as you call it :)), between the black and yellow wires is the limit switch. Between the black and the red is the fan switch. If you unplug the RED wire from this box, the fan should stop running...and if so, then you have it, the fan switch is stuck closed. Sometimes tapping it gently does the trick.

Do you have a belt-drive type of a fan motor here?

The site for picture posting is as follows:
http://photobucket.com/

Wow, thanks so much for being so patient with me...

I will have to post pics later. I have so serious health issues and need to rest a bit now (chronic fatigue)...

It is a Honeywell but I can not find the M/N # for the life of me. at the inside top it says Honeywell then under that city and state but no numbers. If the number is on the upper lip of that box it is covered by a duct (I have to send pics because I dont know how to explain this). I looked everywhere for the #. Sorry!

Concerning the butotns: (hope I can explain this better)...

Near the bottom of the box are some holes (looks like for wrenches) some of the holes are raised and some are flush to the box. The left top most raised button/hole is labeled "PUSH MAN". Again, it seems to be made for a wrench as I pushed on it but it is just raised plastic with a hole??? To the right and a bit lower is a flush hole labeled "PULL AUTO". Far to the right of that it has a small arrow labeled "PUSH RELEASE" but the yellow wire is pretty tight against the box and I can see what that hole/button looks like. The wires are really tight against the box and I am nervous to play with them...

I fired on the heater after setting the pins to your suggestions and it seems to be cycling properly. The fans turn on when you write and the heater stops firing when you write then the dial starts going in the opposite direction. It cools down to a point then the heater fires up again. I think it was the settings.

I will leave it running to see how it goes.

thanks again,

will report back with pics in a couple hours,

frank

It sure looks like you have it working right now...have a heineken on me. And cancel the service call, else you're looking at a minimum $100 for the tech to wipe his boots off on the welcome mat at your entry door and add to that his time and cost of parts that he may recommend replacing. :(

Post the pics if you wish and I'll try giving you more of an insight into this controller.

And remember to replace the air filter at least once every 3 months

Here are the pics (I hope)

http://i278.photobucket.com/albums/kk104/frankjperrotta/controlboxsm.jpg

http://i278.photobucket.com/albums/kk104/frankjperrotta/furnacecloseupsm.jpg

http://i278.photobucket.com/albums/kk104/frankjperrotta/furnacemedsm.jpg

http://i278.photobucket.com/albums/kk104/frankjperrotta/furnacewcoverandtopsm.jpg

Can anyone tell me how old this system is?

About the filters... my dad says they are the washable kind. How can I tell about that?

I cant express how happy I am with all your help.

And it is me that should buy the next round of Heinekin or how about Sapporo :mask:

thanks all,
frank

Here are the pics
Nice pics

Can anyone tell me how old this system is? 30+ years old

About the filters... my dad says they are the washable kind. How can I tell about that? There should be a filter rack at the end of the return duct (the duct that connects to the side of the furnace). ELSE, is no filter rack exists, remove the lower access door, which is called the "blower door". Your pics show that you have removed the upper access door, which is also called the "burner box door" or the "controls door"...the filter should be there. A washable filter looks like a mesh of wire-like material...is metallic looking.

One last thing, your fan-limit switch does "not" have a manual push-button.

I cant express how happy I am with all your help. Hey...to protect and to serve. :)

Nice pics

Thanks, I am always shocked what good pics can come from a somewhat cheap camera.

30+ years old

That is what I thought... Is it time to replace it? What would I look at spending to replace it? It is a pretty small house. I imagine under 1000 sq. ft. (NOT including basement and small crawl space).

I am also guessing that this dinosaur is not very energy efficient. What should I be looking for in a new one?

ELSE, is no filter rack exists, remove the lower access door, which is called the "blower door" the filter should be there. A washable filter looks like a mesh of wire-like material...is metallic looking.

Yeah, that is where it is... I took it out last week and it seemed pretty clean. Where can I find cleaning instructions? When should they eventually be replaced?

One last thing, your fan-limit switch does "not" have a manual push-button.

that is what I thought

Hey...to protect and to serve. :)

cheers all :coffee: