Wood and Oil furnace blower problem

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Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
Clayton housing on left...floor plenum
 

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Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
Blower had been running on wood perfectly until the blower started to thud again. At the end of the short vid the blower began running again. Crazy!!!
 

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brenndatomu

Minister of Fire
Aug 21, 2013
6,570
NE Ohio
It does...can't hear anything abnormal though.
Has anybody looked at the blower, or motor? Is it belt, or direct drive?
So the oil furnace is a down-drafter...that is a piece of the puzzle I was missing...so the oil furnace will have a snap switch in it somewhere to turn the blower on...could be pretty well hidden...and it must be wired in parallel with the FLS on the Clayton...
 

Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
Again, posted twice of the 'thudding of the blower'. Had been running smoothly while FLS on auto... until...
 

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Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
Yes, there is a toggle on the oil furnace to shut everything off. Sorry the sound didn't carry over. The motor on the blower is direct t drive and only thuds when FLS is on auto and wood is being used for heat. Crazy! Once I switch the FLS to 'manual' the thudding stops and the blower works fine. ONLY on wood heat... WTF????
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,570
NE Ohio
You could try jumping out the FLS...that would bypass it, but not sure what will be learned by doing this since the FLS has been replaced once already, with the same results...and pushing the manual switch kinda takes the thermal switch out of the loop anyways....I do agree though, this is a pretty crazy one!
 

Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
You could try jumping out the FLS...that would bypass it, but not sure what will be learned by doing this since the FLS has been replaced once already, with the same results...and pushing the manual switch kinda takes the thermal switch out of the loop anyways....I do agree though, this is a pretty crazy one!
Yes sir! The blower was, just a moment ago, 'thumping" (trying to turn on or off, I believe) so I whacked the Clayton furnace with a good left (I'm getting pissed). The result was the blower (on auto, of course) suddenly turned off, however, manual worked fine. I've reset it to auto and is working as it should. My thinking? A loose or frayed wire may be involved here. The new FLS has been sent, so I will hook it up and hope for the best... if not, I call back the hvac guy with the idea to check the wiring in that thing on the back of the Clayton plenum, which I know nothing about. Any additional ideas are welcome and thank you for your interest. I'LL BE BAAAACCCCKKK!!!
 

laynes69

Minister of Fire
Oct 2, 2006
2,626
Ashland OH
I would separate the off and on temperature more on the fls. Years ago I had a similar setup and the fls would just activate the board on the central furnace through 2 tiny wires, and it worked well. Does the heat of the oil go through the clayton, or the heat from the clayton go through the oil? Also while the system is running, wiggle the wires on the fls and see if anything is loose. Just don't touch anything shiny!
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,570
NE Ohio
I would separate the off and on temperature more on the fls
Agree...it appears to be 125* off, 140* on? Too tight.
Does the heat of the oil go through the clayton, or the heat from the clayton go through the oil?
Has to be the oil blowing through the Clayton, right @Alk ?
Also while the system is running, wiggle the wires on the fls and see if anything is loose. Just don't touch anything shiny!
Exactly. Those Honeywell's use push type terminals, could have a bad connection there.
Its on the limit side, not the fan control side, but it appears that the blue wire is stranded type wire...those push terminals really are meant to be used with solid type wire,,,if stranded was to be used I would at least solder the strands into one.
This pic shows how you can use a screwdriver to release the wires from the terminal.
Beware, there could be 120 V on those wires...probably 24, but just depends how its setup...better to fool with it with power off.

I thought you said earlier that the FLS was already replaced with a no name switch @Alk ? The one in your pic earlier is a Honeywell...
1612703350816.png
 
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Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
Good morning... I originally had a Honeywell fls and maybe I sent an old pic. The brand the HVAC guy brought was an off brand. This is the second one he brought as the first was doing the same thing. I've ordered a Honeywell that will get here late in the week. The settings have been set tight to see if the blower would shut off at the higher temp... didn't work so well. Originally it was set at 100. The wires on the fan side of the fls are thin, but solid. The wire on the limit side is larger and braided. I took apart the electric unit on the back side of the Clayton to check the connections and shape of the wires, as far as I could tell it looked good in there. The jumper wire on the fls was cut so it is a 24 v system. The plenums are continuous through both the oil and Clayton, so only one fls is needed. I just started a fire and the blower is on and off as it should be. We'll see what happens. Thanks for the interest and the picture. Hope we have a good game today...
 

Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
One more thing that you will find interesting... the HVAC tech neglected to cut the jumper wire and ended up shorting out the transformer and the board. Of course he cursed himself and replaced without cost. Accidents happen...
 

Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
And if that's the case, then there probably is only one FLS, and it makes absolutely ZERO sense that the blower would work fine on oil, but not wood...
OK, have done my homework. Contrary to what I was thinking the Oil does have it's own shut off switch and is not controlled by the FLS on the Clayton, which is why the oil works fine. I've wiggled the manual/auto button on the FLS and the blower responds erratically, proving that the FLs (2nd one) is faulty, imo of course. The new Honeywell FLS still hasn't got here...can't wait!
 
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Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
The new 'Honeywell' FLS came in today. It is made in Mexico and is under the name of Resideo, that is exactly the same FLS as the other two failures I got from the local HVAC. Honeywell, your'e making a bunch of worthless JUNK! So, I hooked it up and, of course, got the same results... wouldn't hardly shut off. At least it wasn't shorting out and causing the blower to rapidly turn off and on and bang around like the other two switches did. I watched the dial closely and discovered that it would warm up smoothly but would get 'stuck' when cooling down, thus often wouldn't shut off the fan. I'll be contacting Zoro tomorrow and look for a different manufacturer. At least I now understand the furnace system and what the problem has been all along.
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,570
NE Ohio
wouldn't hardly shut off. At least it wasn't shorting out and causing the blower to rapidly turn off and on and bang around like the other two switches did. I watched the dial closely and discovered that it would warm up smoothly but would get 'stuck' when cooling down, thus often wouldn't shut off the fan.
Won't shut off? Like when the fire is out and the furnace is cold?
Otherwise stayin on is good...no heat to the house if the blower doesn't stay running...most furnaces have the opposite problem, on-off-on-off-on -off all the time! Crazy!
What do you have the on/off temps set to?
 

Alk

New Member
Feb 6, 2021
30
Careywood, Idaho
Well, after dinking around with the 'new' FLS I got it to turn off and on as it should. I readjusted the settings to 110 - 145 -200 and that seemed to free up the switch. So far, as of last night and all day today, the problem seems resolved, so I've put the furnace hardware back together and will return the faulty FLS to the HVAC contractor tomorrow. All is well... good day...
 
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