Lennox Repairman Can't Solve This One
Laird Allshouse
intermittant problem. Frequently, when it starts up, it will only run for a
few moments, then shut down for about 30 seconds, then attempt to start
again. It may cycle this way for up to three times. At some times the
furnace will just "burp" and immediately shut down. In every case the
furnace finally does come on for good and run until the thermostat shuts it
down.
This problem started last year, and the furnace is now six years old.
So far the repairman, in two trips, has replaced the "flapper," checked the
gas pressure and cleaned the filter. He has also checked the thermostat
anticipation setting, which is .6.
I have tried setting the thermostat way up, thinking that when it first
comes on, it might somehow vibrate off when the furnace comes on. No luck
with that either.
The exterior exhaust and air intake are not in any way blocked, and there is
nothing around these pipe which would cause the exhaust fumes to be drawn
back into the intake.
There is one other symptom which may or may not be associated with the
problem. The pulsing of the furnace is uneven whereas, as I recall, it
sounded with a steady hum when the furnace was first installed.
I would appreciate any ideas on this one before I call the repairman again.
Laird
ftwhd
Unfortunately your furnace is a pig to work on. Non Lennox dealers
don't have the knowledge to trouble shoot them. Do yourself a long
term favor and junk it. Parts are unique and expensive for this
furnace plus it's far and few between to where you will find that
certain tech that can troubleshoot and repair this furnace the first
time out.
Output.
I'm sure you will get all kinds of things that "may" be wrong from
this group but chances are none of them will be right. Its pretty
hard to fix something from here. I've seen posts where everything
under the sun is wrong and it turns out to be that the stat was off
LOL. Usually HO posts wanting a diagnosis over the net seldom gets
any *real* help but they are good for starting pissing contests. Now
if you want more input ask which furnace is better. Good luck.
Electricity.
Mike
UA local 370
Mike
UA local 370
On Fri, 3 Dec 1999 15:30:04 -0500, "Laird Allshouse" <lai...@penn.com>
wrote:
Mike
UA Local 370
reply to <ft...@usol.com>
000000001
John Jalad
the ground. Sometime it will take out the control module(not being
grounded).
Good Luck
John
Laird Allshouse <lai...@penn.com> wrote in message
news:mFV14.2192$8H.1...@newsfeed.slurp.net...
AllTemp
need an experienced Lennox tech to look at it for you. Brian argues the thing
isn't proprietary but it is... In my Robertshaw Electronic Ignition Tester ,
Model 975 Lennox is an option you have to order their special wiring harness.
That ought to tell you something... I work on Pulse furnaces now and again but
have never had to condemn one... : -)
Brian S- wrote:
> Hi Laird,
>
> The problem you are describing is usually gas or combustion air
> related...Stoped up flue, exhaust and intake swaped, air flapper
> sticking, etc. You pretty much hit on all thoes. It's been a long
> time since I was the Pulse troubleshooter. I can remember times
> standing in front of a Pulse with problems like what you're
> describing, but I can't remember exactly what the problems were!
>
> The dealer needs to call Lennox and talk to one of their techs. They
> will be able to tell him exactly what to look at. The air flow switch
> was certainly a good start, since it probably had never been changed.
>
> And no, don't go ripping that furnace out (sorry Mike). With the
> exception of the solder fiasco in pre 1988 furnaces, the Pulse is as
> neary trouble free as they come. Problem is when someone doesn't
> understand something they talk bad about it, and most don't understand
> the Pulse. (Mike, how much Pulse training have you had? How many
> Pulse furnaces have you worked on?)
>
> And Laird, would you do us all a favor? When you get it fixed, let us
> know the problem.
>
> Brian
>
> "Laird Allshouse" <lai...@penn.com> wrote:
>
> >I have a Lennox Pulse 21 furnace (model G21Q4/5-100-3) which has an
> >intermittant problem. Frequently, when it starts up, it will only run for a
> >few moments, then shut down for about 30 seconds, then attempt to start
> >again. It may cycle this way for up to three times. At some times the
> >furnace will just "burp" and immediately shut down. In every case the
> >furnace finally does come on for good and run until the thermostat shuts it
> >down.
> >
> >This problem started last year, and the furnace is now six years old.
> >
> >So far the repairman, in two trips, has replaced the "flapper," checked the
> >gas pressure and cleaned the filter. He has also checked the thermostat
> >anticipation setting, which is .6.
> >
> >I have tried setting the thermostat way up, thinking that when it first
> >comes on, it might somehow vibrate off when the furnace comes on. No luck
> >with that either.
> >
> >The exterior exhaust and air intake are not in any way blocked, and there is
> >nothing around these pipe which would cause the exhaust fumes to be drawn
> >back into the intake.
> >
> >There is one other symptom which may or may not be associated with the
> >problem. The pulsing of the furnace is uneven whereas, as I recall, it
> >sounded with a steady hum when the furnace was first installed.
> >
> >I would appreciate any ideas on this one before I call the repairman again.
> >
> >Laird
> >
> >
--
MDamron,AllTemp Heating & Cooling
Visit our questions and answers bulletin board ...
( HVAC Q & A ) http://www.alltemphvac.net/board
Brian S-
Bob
It's 6 years old and needs a new air flapper, but I would wonder why the
tech hasn't done this already.
The other is a little known problem with the Pulse.
The tube which delivers the gas into the combustion chamber is called a
gas velocity tube. It can have a build up of corrosion on the end of it,
causing the gas to be deflected upwards as it enters the chamber, and
doesn't get ignited by the spark plug. Eventually some of the gas is
ignited, and may sustain ignition, or may burp and flutter like you
described.
The fix is to remove the spark plug and insert a 1/4" drill bit through
the spark plug hole and straight across into the opening of the gas
velocity tube. Ream it out and you may solve your problem.
Also, make sure the purge motor is working.
A pulse can sometimes ignite with a burned out purge blower if the
venting is experiencing a venturi effect caused by an outdoor breeze,
again with a rough start. If it's calm outdoors the next day, it may not
ignite like it did the day before.
Respectfully, Bob
airf...@webtv.net
AllTemp
this before I am occasionally found on a service call with one. What
most service guys find when confronted with a Pulse for the 1st time is a
lot of hair pulling. I'll never forget my 1st I didn't know what the hell
I was looking at... : - ) The most recent service call was on a Pulse in
which the customer had already had two other service companies out before
we arrived. A small investment in some tools and a little experience go a
long way.
Again, enjoyed your post !
Brian S- wrote:
> airf...@webtv.net wrote:
> >Exactly what is an air flapper?
>
> The Pulse furnace works by injecting a small amout of gas and air into
> a chamber, then lighting it with a spark. The flappers allow the air
> and gas into the chamber, but does not allow either back out. The air
> flapper is about 3" diameter, the gas flapper is about 1" in diameter.
>
> On a call for heat the inducer runs to purge all old gas products out
> of the system (the inducer pushes air rather than pulling the fumes
> out). Then the spark plug sparks, the gas valve opens, and air is
> pushed into the "chamber". This creates an explosion. (The marketing
> people thought "pulse" sounded better, thus the name.) The "pulse"
> pressurizes the chamber closing the flappers for the gas and air. The
> explosion is pushed up a pipe. As it goes into the pipe the chamber
> is now under negative pressure, so gas and air are sucked back in.
> The spark plug runs only a few seconds to start this process going.
> After that the last explosion itself ignites the next gas and air
> mixture that is being sucked in. The inducer also shuts off and is
> not turned on again untill the end of the heat cycle when used as a
> post purge.
>
> So, while operating the Pulse uses no inducer, no spark plug, and the
> air flow switches are normally closed. As long as air and gas are
> available, the combustion process will go on forever. The Germans
> invented this during WW2 (the old "buzz bombs").
>
> Hope this helps.
>
> Brian
AllTemp
the thing had been operated without a filter for some time. I pulled
the inspection cover for the exchanger and showed the customer the build
up that had migrated through the coil. Qouted them a figure to come
back and clean it and have it scheduled for the 1st of the year after
the holidays.
The replaced control board got it running again until we can have it
completely tune-up and serviced. Lennox had updated the flue pipe on
this one but the furnace is a post Pulse after their exchanger problem .
: -)
Brian S-
Brian S-
> The most recent service call was on a Pulse in
>which the customer had already had two other service companies out before
>we arrived.
Hi Mell,
What did you find to be the problem on that call?
>> So, while operating the Pulse uses no inducer, no spark plug, and the
>> air flow switches are normally closed.
Something else....the fan in the heat mode is turned on by a good ole
Honeywell fan/limit. In cooling, the fan is turned on with a 24v
relay energized by the green wire. From the thermostat W terminal the
white wire goes thru 2 normally closed air flow switches, then
straight to the ignition module. The ignition module turns the
inducer fan on and off. I know this is much more than was orginally
asked, but just wanted to make the answer complete!
I wish more manufacturers would make furnaces with fan/limits and 24v
relays. Why the need for all this fancy electronics?
Brian
Brian S-
> The air flow switch was certainly a good start, since it probably had never been changed.
Huh? I think I meant the air flapper. My mistake.
Brian
airf...@webtv.net
here... Mostly heat pumps.
Bob
module, right?)
Too much!
Respectfully, Bob
AllTemp
didn't know which way to run... The 1st one told the customer they'd be
back with parts and never came back the 2nd guy was honest enough to
tell the customer they needed someone familiar with this model Lennox.
If I said board I'm referring to the Lennox Blk Ignition Module. Unless
you've hand some hands on you're going to be working on it blind. I did
the 1st one I ever saw... I've got a pretty good understanding with my
Lennox distributors counter guy... Good old Charlie loves to explain
things and if you've got an ear he'll teach you everything you need to
know!
--
MDamron,AllTemp Heating & Cooling
Wishing All Our Friends In Alt.Hvac A Happy And Joyful Holiday Season!
http:/www.alltemphvac.net/Greetings.html
sh...@ecn.ab.ca
: Input.
: Unfortunately your furnace is a pig to work on. Non Lennox dealers
: don't have the knowledge to trouble shoot them. Do yourself a long
: term favor and junk it. Parts are unique and expensive for this
Excuse me? You are telling someone to JUNK a six-year-old furnace? Easy
for YOU to say.
: furnace plus it's far and few between to where you will find that
: certain tech that can troubleshoot and repair this furnace the first
: time out.
: Output.
: I'm sure you will get all kinds of things that "may" be wrong from
: this group but chances are none of them will be right. Its pretty
: hard to fix something from here. I've seen posts where everything
: under the sun is wrong and it turns out to be that the stat was off
: LOL. Usually HO posts wanting a diagnosis over the net seldom gets
: any *real* help but they are good for starting pissing contests. Now
: if you want more input ask which furnace is better. Good luck.
: Electricity.
: Mike
: UA local 370
: Mike
: UA local 370
: On Fri, 3 Dec 1999 15:30:04 -0500, "Laird Allshouse" <lai...@penn.com>
: wrote:
: >I have a Lennox Pulse 21 furnace (model G21Q4/5-100-3) which has an
: >intermittant problem. Frequently, when it starts up, it will only run for a
: >few moments, then shut down for about 30 seconds, then attempt to start
: >again. It may cycle this way for up to three times. At some times the
: >furnace will just "burp" and immediately shut down. In every case the
: >furnace finally does come on for good and run until the thermostat shuts it
: >down.
: >
: >This problem started last year, and the furnace is now six years old.
: >
: >So far the repairman, in two trips, has replaced the "flapper," checked the
: >gas pressure and cleaned the filter. He has also checked the thermostat
: >anticipation setting, which is .6.
: >
: >I have tried setting the thermostat way up, thinking that when it first
: >comes on, it might somehow vibrate off when the furnace comes on. No luck
: >with that either.
: >
: >The exterior exhaust and air intake are not in any way blocked, and there is
: >nothing around these pipe which would cause the exhaust fumes to be drawn
: >back into the intake.
: >
: >There is one other symptom which may or may not be associated with the
: >problem. The pulsing of the furnace is uneven whereas, as I recall, it
: >sounded with a steady hum when the furnace was first installed.
: >
: >I would appreciate any ideas on this one before I call the repairman again.
: >
: >Laird
: >
: Mike
: UA Local 370
: reply to <ft...@usol.com>
--
Brian S-
Commenting about the Lennox Pulse, G21...
> Parts are unique and expensive for this
>furnace (the Pulse)
Hi Mike,
My first chance to call Lennox and provide some fact to your
statement: I have checked previously about what non-Lennox dealers
pay for Lennox parts, and it is only slightly more than dealers. I
have only the prices for dealers...
- The ignition module (same one used on all Pulse furnaces), includes
conversion kit, cost less than $95. (there of 26 of them at my
distributer)
- The inducer assembly (same one used on all Pulse furnaces) is less
than $20 (even I find that hard to believe, but that's what they tell
me, includes motor, blower wheel, housing, etc.) (12 of these at my
distributer)
- The sensor (again, same one used on all Pulse furnaces) is less than
$15.
I don't have to tell you what a 24v relay and fan/limit cost. From
what I see, the prices are quite reasonable. Actually, looks to me
like the Pulse parts may be about THE LEAST EXPENSIVE OF ANY OTHER 90%
FURNACE??? As I have stated, the Pulse may be intimidating at first,
but is a very simple and reliable design. Don't confuse it with the
Triathlons and Amana Glycol furnaces of the past. The original
poster's Pulse was built after 1988 (after the solder episode).
I don't like to get into pricing, but at least it provides some
substance to counter unsubstantiated claims.
Brian
Sonofdawra
>isn't proprietary but it is... In my Robertshaw Electronic Ignition Tester ,
>Model 975 Lennox is an option you have to order their special wiring harness.
How do you like your Robertshaw Electronic Ignition Tester?
ftwhd
cheaper than cheap, easily obtainable and mostly generic. :) I
haven't experienced the problems that some have in obtaining parts,
but I have experienced problems getting the *right* parts and 9 times
out of 10 the price I pay seems way out of line. But that may be due
to the fact that were not a Lennox dealer I dunno. That inducer motor
does sound really cheap though, I think I'll call our distributor and
see what we would get it for when I have a few extra moments.
Mike
UA local 370
On Mon, 06 Dec 1999 13:44:43 GMT, Br...@SpencerAir.com (Brian S-)
wrote:
ftwhd
wrote:
>
>Hi Mike,
>
>My first chance to call Lennox and provide some fact to your
>statement: I have checked previously about what non-Lennox dealers
>pay for Lennox parts, and it is only slightly more than dealers. I
>have only the prices for dealers...
>
snip
Hey Brian, I checked with our local Lennox dealer today and I'll be
damned :) 18.36 for the inducer. I stand corrected.
Brian S-
>Hey Brian, I checked with our local Lennox dealer today and I'll be
>damned :) 18.36 for the inducer. I stand corrected.
Hi Mike,
I, too, was doubting if that was correct. Wonder what it's made of??
I have never had the need to replace one.
Brian
ftwhd
wrote:
>ftwhd wrote:
I don't know, Its been a long time since I've seen the innards of a
Pulse I don't remember what the inducer looks like. It sure cant be
much though. Not for that price anyway.
Laird Allshouse
some time listening to the furnace. Prior to the furnace's attempt to start
I heard what I would guess is a purging fan start up. It actually started
for a few seconds, stopped for about 30 seconds, started again and repeated
this cycle three times when, while it was running, the furnace started.
Once again, and on a continuing basis, the furnace only runs briefly for a
couple of times until it finally settles into a full cycle.
I don't know if this helps with the diagnosis, but thought I would post it
for your information.
In the meantime, I have provided my repairman with copies of all of the
messages posted here, and I want to thank you for your suggestions.
If we get this thing solved I will advise what the fix was.
Regards,
Laird
"Brian S-" <spen...@mindspring.com> wrote in message
news:3849e15...@news.mindspring.com...
> airf...@webtv.net wrote:
> >Exactly what is an air flapper?
>
> The Pulse furnace works by injecting a small amout of gas and air into
> a chamber, then lighting it with a spark. The flappers allow the air
> and gas into the chamber, but does not allow either back out. The air
> flapper is about 3" diameter, the gas flapper is about 1" in diameter.
>
> On a call for heat the inducer runs to purge all old gas products out
> of the system (the inducer pushes air rather than pulling the fumes
> out). Then the spark plug sparks, the gas valve opens, and air is
> pushed into the "chamber". This creates an explosion. (The marketing
> people thought "pulse" sounded better, thus the name.) The "pulse"
> pressurizes the chamber closing the flappers for the gas and air. The
> explosion is pushed up a pipe. As it goes into the pipe the chamber
> is now under negative pressure, so gas and air are sucked back in.
> The spark plug runs only a few seconds to start this process going.
> After that the last explosion itself ignites the next gas and air
> mixture that is being sucked in. The inducer also shuts off and is
> not turned on again untill the end of the heat cycle when used as a
> post purge.
>
> So, while operating the Pulse uses no inducer, no spark plug, and the
Brian S-
>Prior to the furnace's attempt to start
>I heard what I would guess is a purging fan start up. It actually started
>for a few seconds, stopped for about 30 seconds, started again and repeated
>this cycle three times when, while it was running, the furnace started.
Hi Laird,
That's great info to have. Hopefully it will be acting up when the
svc man is there. Could be the inducer motor is getting voltage but
overheating and quiting. Could be one of the air flow switches is
opening, breaking voltage to the ignition (which in turn energizes the
inducer). Could be the ignition module itself is cutting the inducer
motor off.
Bob mentioned earilier about a possible inducer fan problem, but the
unit finally starts. He may have been right on?
Brian
AllTemp
working on a Pulse you don't have a Lennox service company repairing it? Or
better yet it's not fixed yet ?
Laird Allshouse wrote:
> I'm the original poster of this problem. This morning I went down and spent
> some time listening to the furnace. Prior to the furnace's attempt to start
> I heard what I would guess is a purging fan start up. It actually started
> for a few seconds, stopped for about 30 seconds, started again and repeated
> this cycle three times when, while it was running, the furnace started.
>
--
MDamron,AllTemp Heating & Cooling
Wishing All Our Friends In Alt.Hvac A Happy And Joyful Holiday Season!
http://www.alltemphvac.net/Greetings.html
Laird Allshouse
last year, were Lennox dealers. They switched to Trane.
"AllTemp" <All...@Pacbell.net> wrote in message
news:384EF49B...@Pacbell.net...
AllTemp
Corky
take a look at his neighbors unit. The neighbor had a pulse, installed
and maintained by a reputable Lennox dealer.
Same problem, sometimes furnace would call purge die, sometimes call
purge ignite run afew minutes or less and die, sometimes it would start
fine run for several days and die. The customer said that occasionally
he could cycle stat for several times and after a few tries, get it to
run fine.
Lennox trained guys had changed all elec parts, all pressure switches,
they had determined after all this parts changing that the exaust pipe
had developed a swag and was holding condensate like a trap.The pipe was
run to the outside inside a partition wall, and there were a couple of
the homebuilders guys there taking the sheetrock off so this could be
repaired.
I tried the furnace, it called purged died, after two or three attemts,
it fired and ran. I shut it off went outside shined light down exaust
and intake and could see to the ells that turned down at furnace. Went
back inside and while kneeling down in front off the beast, I noticed a
little water on the floor, showed neighbor,he said condenstate pump was
in unfinished room on other side of wall. I went around and found the
pump sitting on the ground surrounded by water and algae was everywhere,
I had had condensating furnaces in the past stopped by the drains being
blocked by algae, so I went back to furnace, removed drain line at
furnace and water poured out.
Evidently the algae had the drain blocked enough to slow down draining
of the furnace, this is why it would work erratically, the cust noted
that if the furnace sat idle for quite a while it would start and run
fine, but during periods when it had to run a lot it would misbehave.
I rigged up a "bucket drain" and manually, by using jumper wire, let
furnace run thru several cycles, I would unhook jumper every 5-10 mins,
then let sit a few, then re connect, it ran fine for about 1 hour.It has
ran fine ever since. The wall was uncovered, the pipes were fine, the
Lennox guys replaced pump and re-did drains. I do the mans maintanance
now,hehehe.
* Sent from RemarQ http://www.remarq.com The Internet's Discussion Network *
The fastest and easiest way to search and participate in Usenet - Free!
Bob Loblaw
you first posted about this, I assumed that some common ailments had
been addressed, but now, by the way you're talking, I'm not so sure what
they've done to it as far as diagnosis goes.
Air flappers are a common trouble maker after 5 to 7 years.
Next is the purge blower. And don't let them make the mistake I made.
At a course taught by Lennox, they suggested putting a screw driver to
the housing that contains the purge blower to hear if its running, thus
saving you time by not having to remove the miriad of screws that hold
on the cover. I heard it allright. It was humming away. But it was
seized! I wasted a lot of time on that one thinking the purge was O.K.
One last word of advice. A rough running Pulse can also be caused by a
hole in the refractory tube, a common place for structural failure in a
Pulse.
Respectfully, Bob
Bob Loblaw
What exactly has been done to this furnace so far, in the way of a
diagnosis? Have they pulled anything apart? Have they checked the
integrity of the exchanger? Do they even know how to check it? Ask them.
They should be sealing off both intake and exhaust pipes, then running
the blower compartment fan with a slope guage connected to the gas test
nipple, with the gas turned off at the valve. If they get any movement
on the guage, the exchanger is toast.
Respectfully, Bob
ftwhd
wrote:
>"Laird Allshouse" <lai...@penn.com> wrote:
>
>>Prior to the furnace's attempt to start
>>I heard what I would guess is a purging fan start up. It actually started
>>for a few seconds, stopped for about 30 seconds, started again and repeated
>>this cycle three times when, while it was running, the furnace started.
>
>Hi Laird,
>
>That's great info to have. Hopefully it will be acting up when the
>svc man is there. Could be the inducer motor is getting voltage but
>overheating and quiting. Could be one of the air flow switches is
>opening, breaking voltage to the ignition (which in turn energizes the
>inducer). Could be the ignition module itself is cutting the inducer
>motor off.
>
>Bob mentioned earilier about a possible inducer fan problem, but the
>unit finally starts. He may have been right on?
>
>Brian
Sure sounds like an inexpensive repair to me :). The *purge blower*
(instead of inducer) motor needs replaced. Verified by whether or not
there is voltage to the motor when it quits during the initial startup
phase. If its quits working and has voltage, replace the purge motor.
If no voltage is present then, the motor is probably fine.
doc...@pop.sxfl.uswest.net
Please keep in mind ...The small town and rural repair folks have some extra
expenses in ware-housing parts etc. A smaller customer base. And when the town
needs some extra money--they are expected(no..commanded) to chip in big time..
Of course things will be less expensive in a larger community that has wholesale
distributors on every corner. Most service companies can get by with a minimal
inventory and parts are readily available at the distributorships..Also have a
much larger customer base..Also in the farm communities...many times the Service
outfit is expected to carry a bill until the farm check comes...or in the small
towns the social security check(a lot of old folks live innem). We have the
problem here that the small towns are dying out and the customers out there are
not as numerous and a lot of folks don't want to pay the going rate. Also if
they live 37 miles out ...Don't want to pay mileage.. Consequently the service
company's sons take over and move to a larger town..Then the whining starts "WE
can't get service out here...Well the guys just got tired of maintaining
,insuring a massive warehouse full of parts that went obsolete and couldn't be
sold...Got tired of a hand to mouth existance and then snarled at when the bill
was rendered...Most pack up and leave with tens of thousands in unpaid
bills...coulda prosecuted,but what the heck...The customers were neighbors and
some of them recieve minimum social security...Never mind the furnace was
repaired 30 miles out at 3:15 in the morning, after driving through a blinding
blizzard....And the Service guy's son is crabby as all get out, that he had to
grab a shovel and go along....He has to be at work down to the Co-op at 6:00
am...
Now when one of the guys quits and goes off....It is usually to a large city and
he certainly is not competition....In some area's ...There isn't much to compete
for and you will find your HVAC guy raising cattle etc...just to make ends
meet. I don't live in the sticks, but if you do ....I suggest you support your
local businesses.. If you don't ....They will starve out and move on..That means
everything from grocery stores, hardware whatever.....
Laird Allshouse wrote:
> We are captives of small-town and very rural servicing companies. I talked
> to the repairman about how long he had been working for the company. He
> said six years. He said most guys work for a few years and then go off on
> their own. The result is that few really get in-depth experience and tech
> know-how on these things.
>
> I do not have an annual service agreement so, after 6 years, I now have
> about $450 in the maintenance of the furnace, including the cost of the
> module. That figures out to about $75 a year, same as the annual service
> cost.
>
> Next time this happens I'll get one of the $90 module from you guys and fix
> it myself.
>
> "AllTemp" <All...@Pacbell.net> wrote in message
> news:3851A9F1...@Pacbell.net...
> > The control module was replaced this morning, gee. Listen didn't they
> test the
> > module the 1st trip there ? Oh ya almost forgot ! A service tech doesn't
> need
> > all those expensive high tech gadgets. Isn't that what someone one
> replied to
> > my post ?
> >
> > A simple procedure of checking the module in the appliance could have been
> done
> > using any number of electronice module testers on the market. I use the
> > Robershaw- Un-Line #900-575, I believe the Lennox part number for the
> wiring
> > harness for the etest procedure is 33J6201 . Had this been done to rule
> out
> > the control module all this delay could have been avoided. I earlier said
> I
> > would have lost confidence in this service company long ago ! Did they
> discount
> > your repair ? After all it looks like it was structly a training course
> held at
> > your inconvenience on your Pulse, lol !
> >
> > But I'm glad to hear you have it repaired.
> >
> > Laird Allshouse wrote:
> >
> > > The control module was replaced this morning, apparently fixing the
> problem.
> > > I say apparently because the problem was intermittant. I'll monitor it
> for
> > > a
> > > couple of days before I'll be satisfied that it is actually fixed.
> > >
> > > BTW, I had complained about the furnace running "rough." It now seems
> to
> > > run
> > > smoother.
> > >
> > > Thanks to all who made recommendations.
> > >
> > > Laird
> > >
> > > "Laird Allshouse" <lai...@penn.com> wrote in message
> > > news:QBz34.91$Ww1....@newsfeed.slurp.net...
> > > > I'm the original poster of this problem. This morning I went down and
> > > spent
> > > > some time listening to the furnace. Prior to the furnace's attempt to
> > > start
> > > > I heard what I would guess is a purging fan start up. It actually
> started
> > > > for a few seconds, stopped for about 30 seconds, started again and
> > > repeated
> > > > this cycle three times when, while it was running, the furnace
> started.
> > > >
Laird Allshouse
AllTemp
module the 1st trip there ? Oh ya almost forgot ! A service tech doesn't need
all those expensive high tech gadgets. Isn't that what someone one replied to
my post ?
A simple procedure of checking the module in the appliance could have been done
using any number of electronice module testers on the market. I use the
Robershaw- Un-Line #900-575, I believe the Lennox part number for the wiring
harness for the etest procedure is 33J6201 . Had this been done to rule out
the control module all this delay could have been avoided. I earlier said I
would have lost confidence in this service company long ago ! Did they discount
your repair ? After all it looks like it was structly a training course held at
your inconvenience on your Pulse, lol !
But I'm glad to hear you have it repaired.
Laird Allshouse wrote:
--
Laird Allshouse
cost to the servicing company.
<ftwhd> wrote in message news:i3435s43drqv7vkal...@4ax.com...
> I'm glad you got it fixed. I'm curious how much was the bill?
> Mike
> UA local 370
> <reply to ft...@usol.com>
Laird Allshouse
to the repairman about how long he had been working for the company. He
said six years. He said most guys work for a few years and then go off on
their own. The result is that few really get in-depth experience and tech
know-how on these things.
I do not have an annual service agreement so, after 6 years, I now have
about $450 in the maintenance of the furnace, including the cost of the
module. That figures out to about $75 a year, same as the annual service
cost.
Next time this happens I'll get one of the $90 module from you guys and fix
it myself.
"AllTemp" <All...@Pacbell.net> wrote in message
news:3851A9F1...@Pacbell.net...
> The control module was replaced this morning, gee. Listen didn't they
test the
> module the 1st trip there ? Oh ya almost forgot ! A service tech doesn't
need
> all those expensive high tech gadgets. Isn't that what someone one
replied to
> my post ?
>
> A simple procedure of checking the module in the appliance could have been
done
> using any number of electronice module testers on the market. I use the
> Robershaw- Un-Line #900-575, I believe the Lennox part number for the
wiring
> harness for the etest procedure is 33J6201 . Had this been done to rule
out
> the control module all this delay could have been avoided. I earlier said
I
> would have lost confidence in this service company long ago ! Did they
discount
> your repair ? After all it looks like it was structly a training course
held at
> your inconvenience on your Pulse, lol !
>
> But I'm glad to hear you have it repaired.
>
4cav...@gmail.com
> I have a Lennox Pulse 21 furnace (model G21Q4/5-100-3) which has an
> intermittant problem. Frequently, when it starts up, it will only run for a
> few moments, then shut down for about 30 seconds, then attempt to start
> again. It may cycle this way for up to three times. At some times the
> furnace will just "burp" and immediately shut down. In every case the
> furnace finally does come on for good and run until the thermostat shuts it
> down.
>
> This problem started last year, and the furnace is now six years old.
>
> So far the repairman, in two trips, has replaced the "flapper," checked the
> gas pressure and cleaned the filter. He has also checked the thermostat
> anticipation setting, which is .6.
>
> I have tried setting the thermostat way up, thinking that when it first
> comes on, it might somehow vibrate off when the furnace comes on. No luck
> with that either.
>
> The exterior exhaust and air intake are not in any way blocked, and there is
> nothing around these pipe which would cause the exhaust fumes to be drawn
> back into the intake.
>
> There is one other symptom which may or may not be associated with the
> problem. The pulsing of the furnace is uneven whereas, as I recall, it
> sounded with a steady hum when the furnace was first installed.
>
> I would appreciate any ideas on this one before I call the repairman again.
>
> Laird
no inducer fan ok. thermostatic calls for heat right. pilot flame on Limit switch senses temperature then sends signal to fan side of fan/limit switch after limit switch turns on main burners the fan comes on right. when temperature is satisfied main burners turn off fan runs for short time to cold down furnace. cycle then starts when thermostatic calls for heat again. right.
Think about it, fan/limit combo control switch are two switches in one body.
One is the safely with is the limit side which also is a temperature turn off and on switch and the other is the fan side which turns on the main fan.
any other safely features that would cause main burner not to fire up and cause flame to snuff out would then need investigating and repaired whether an igniter
or clogged offisas ( burners ). Hope you get it fix and hope you learn something about furnace`s as I am self studing at home. try these books Electromechanical and Electronic controls for HVAC/R by Billy C. Langley also study electrical fundamentals and systems for HVAC/R by Thomas Horan share knowledge.
Stormin Mormon
--
.
Christopher A. Young
learn more about Jesus
. www.lds.org
.
.
Moe DeLoughan
consigned to the scrap heap long since.
Stormin Mormon
TV Dinners, Wilma?
Tony Hwang
sensor first. Furnace operation is single line logic flow. When flame
comes on sensor should sense it to continue running.