any new gas furnaces with pilot light?
tomja...@tomjwatson.ibm.com
Does any gas furnace manufacturer make one with a pilot light?
Do the hot bar ignitions on gas furnaces really save money, if
one includes the added costs of electricity and repairs (? - I'm
assuming an ignition system is more likely to fail than a pilot)?
To reply by email, remove the 2 "tomj"'s from my email address.
Thanks.
R. Kalia
In article <5vrbgr$h8f$1...@watnews1.watson.ibm.com>,
tomja...@tomjwatson.ibm.com says...
>
>Does any gas furnace manufacturer make one with a pilot light?
No. It would be difficult for manufacturers to meet the minimum
efficiency standard (78%) if they used pilots.
>Do the hot bar ignitions on gas furnaces really save money, if
>one includes the added costs of electricity and repairs (? - I'm
>assuming an ignition system is more likely to fail than a pilot)?
Why would you assume that? Old is not automatically better than new.
There is no significant electricity cost, because the ignition only draws
electricity for a few seconds at a time. A pilot light, however, has to be
on all the time.
As for maintenance, the pilot needs a thermocouple in it to detect that the
flame is on (safety precaution; furnace won't send gas to burners unless
pilot is lit) The thermocouple needs to be changed every couple of years
(the maintenance people like to change it every year, but that's probably
not strictly necessary).
David
>
> . Does any gas furnace manufacturer make one with a pilot light?
> . Do the hot bar ignitions on gas furnaces really save money, if
> . one includes the added costs of electricity and repairs (? - I'm
> . assuming an ignition system is more likely to fail than a pilot)?
>
> I think your assumption may be faulty. I had an electronic ignition
> furnace for ten years -- and about the only component on it that _didn't_
> fail was the auto-ignition.
>
> --
> Kirk & Diane Kerekes
> Red Gate Ranch
> red...@tulsa.oklahoma.net
The hot surface ignitor in my furnace failed shortly after install. It
was replaced and failed again about six years later. Thsi time I bought
one and replaced it myself (One screw and a plug). For reference, My
water heater thermocouple failed after 8 years. Anything that senses
heat while immersed in a flame will eventually fail. The hot surface
ignitor in my Rheen 80+ is also a sensor. The controller energizes a
small relay to supply 115vac to ignite and about 20 seconds later, the
relay denergizes and connects the HSI leads over to a circuit that
senses voltage/current from that HSI, much like a thermocouple would
work.
The good part about HSI devices is that they only consume power when
needed, not 24 hours per day.
--
_______________________________________________
What the heck? ... it's just my opinion!
To reply, delete NOSPAM from my email address.
_______________________________________________
John Mills
> >Does any gas furnace manufacturer make one with a pilot light?
>
> efficiency standard (78%) if they used pilots.
>
standing pilot. So do BDP/Carrier and Coleman who also sells under
the parent York name. We put in a York P1SPD yesterday which
was standing pilot 78% AFUE.
> >Do the hot bar ignitions on gas furnaces really save money, if
> >one includes the added costs of electricity and repairs (? - I'm
> >assuming an ignition system is more likely to fail than a pilot)?
Most hot surface ignitors last anywhere from 1 to 5 years. Until
our WeatherKing distributor stopped stocking the 78% pilot model,
I pushed them. Customers can light their own pilots. But few
can change ignitors. Now, White-Rodgers has come out with a new
type of ignitor that supposedly is virtually indestructible. Honeywell
has the Smart Valve system which is a low voltage ignitor that lights
a pilot. And some brands have switched BACK to spark - such as Rheem
which was one of the first to use hot surface ignition.
> There is no significant electricity cost, because the ignition only draws
> electricity for a few seconds at a time. A pilot light, however, has to be
> on all the time.
The GAMA directory lists estimates of annual energy costs. Using that
chart
we compared 2 Rheem models, the 78% pilot and the 80% hot surface. Using
the
book's data for gas & electricity costs, the extra gas savings over not
having the pilot was lost to the electric savings of not having the
ignitor.
Not my data, verified by the ETL.
>
> As for maintenance, the pilot needs a thermocouple in it to detect that the
> flame is on (safety precaution; furnace won't send gas to burners unless
> pilot is lit) The thermocouple needs to be changed every couple of years
> (the maintenance people like to change it every year, but that's probably
> not strictly necessary).
Hot surface systems require flame sense rods to report to the module
that the
fire is on. These need to be cleaned frequently. In a polluted
environment
it can be as often as 1 year. Some can go several years.
--
Visit me!
http://www.geocities.com/~johnmills
David B
John Bunting wrote:
>
> In 6 years I have had one hot bar igniter fail(open up) on a zero
> degree F. night. I keep a spare now. They are only $20+ each.
>
> On 19 Sep 97 02:39:34 GMT, "Scott" <jo...@trader.com.spam> wrote:
> > >
> >tomja...@tomjwatson.ibm.com wrote in article
> ><5vrbgr$h8f$1...@watnews1.watson.ibm.com>...
> >>
> >> Does any gas furnace manufacturer make one with a pilot light?
> >> one includes the added costs of electricity and repairs (? - I'm
> >> assuming an ignition system is more likely to fail than a pilot)?
>
> >>
> >pilot but I'm not sure if they still make it. The power that a hot surface
> >igniter uses should be very small as they are only on a few seconds each
> >heating cycle. The controls used for hot surface ignition are for the most
> >part very good. The weak links are the sensor and the igniter both
> >inexpensive parts. The added safety that these systems provide may well be
> >worth any additional service required. I might add IMHO that trouble
> >shooting and repair is not any harder than a standing pilot.
> >
> >Scott
Personal experience: in our previous house we had a Lenox Pulse high efficiency
furnace, which I was very happy with. Over a period of 8 years, however, the only
part we had to replace was the ignitor. (It didn't just fail on the coldest day of
the year, but on a Friday night before a long weekend.) I forget the cost, but I
sure wish it had only been $20. Oh, and they had to replace it again two weeks
later (under warranty) when the first replacement failed.
Scott
tomja...@tomjwatson.ibm.com wrote in article
<5vrbgr$h8f$1...@watnews1.watson.ibm.com>...
>
> Does any gas furnace manufacturer make one with a pilot light?
> Do the hot bar ignitions on gas furnaces really save money, if
> one includes the added costs of electricity and repairs (? - I'm
> assuming an ignition system is more likely to fail than a pilot)?
>
> To reply by email, remove the 2 "tomj"'s from my email address.
>
> Thanks.
>
John Bunting
In 6 years I have had one hot bar igniter fail(open up) on a zero
degree F. night. I keep a spare now. They are only $20+ each.
On 19 Sep 97 02:39:34 GMT, "Scott" <jo...@trader.com.spam> wrote:
Jim Sokoloff
David B wrote:
> Personal experience: in our previous house we had a Lenox Pulse high efficiency
> furnace, which I was very happy with. Over a period of 8 years, however, the only
> part we had to replace was the ignitor. (It didn't just fail on the coldest day of
> the year, but on a Friday night before a long weekend.) I forget the cost, but I
> sure wish it had only been $20. Oh, and they had to replace it again two weeks
> later (under warranty) when the first replacement failed.
It sounds to me like you paid someone to come drive out and install it
(which is fine, no personal insult intended), but that's of course going
to cost you more than $20 in labor alone. How much was the part?
---Jim
sh...@freenet.edmonton.ab.ca
: >
: >Does any gas furnace manufacturer make one with a pilot light?
: No. It would be difficult for manufacturers to meet the minimum
: efficiency standard (78%) if they used pilots.
: >Do the hot bar ignitions on gas furnaces really save money, if
: >one includes the added costs of electricity and repairs (? - I'm
: >assuming an ignition system is more likely to fail than a pilot)?
: Why would you assume that? Old is not automatically better than new.
: There is no significant electricity cost, because the ignition only draws
: electricity for a few seconds at a time. A pilot light, however, has to be
: on all the time.
: As for maintenance, the pilot needs a thermocouple in it to detect that the
: flame is on (safety precaution; furnace won't send gas to burners unless
: pilot is lit) The thermocouple needs to be changed every couple of years
: (the maintenance people like to change it every year, but that's probably
: not strictly necessary).
--
WHOA!!! Did you just say EVERY COUPLE of years, re: changing thermocouple?
My Lennox thermocouple failed after, would you believe, 15 months????
At the time, since the furnace was almost brand new, I panicked and
assumed that there had to be a complicated reason for the "no heat"
condition. So...... $107 CAN later..2 hours labor and 7 bucks for the
thermocouple, I found out the reason. At the time the serviceman from
Alpine Heating in Edmonton, Alberta, said, that in future, if the problem
happened, to simply remove the thermocouple, rub the buildup off with a
scouring cloth (one of the green/brown whatever plastic abrasive cloths)
and reinstall the device. He said that the reason he replaced the original
thermocouple was that it was badly corroded (after 15 months) from natural
gas impurities. The local natural gas company performed thorough analyzes
of the natural gas..if you want the specs, please email me.... They said
that Alpine was out to lunch. However, when the gas company contacted
ALpine about their impure gas claim, Alpine, (the local Lennox dealer
which installed the furnace) totally denied the comment.
I have had other furnaces, where in 10 years time, presented NO problems,
save for cleaning the filters, and lubrication, depending on whether or
not the blower motor design required it.
The install was done in fall, 1993. Last week, when the furnace came on
for the first time this heating season, it took 3 tries before the
thermocouple detected flame. Since then it has be OK...without any
cleaning. Oh, Alpine also suggested that Lennox furnaces where designed
for "cleaner" natural gas in Texas. Yeah, right. Their crummy parts only
warrantee only covers for 1 year, except for the heat exchanger and the
circuit board. This is just the tip of the iceberg on the troubles I have
had with that installation. More in later posts on the power humidifier,
the electronic air cleaner and the manual switch they installed for 24
hour air circulation.
dave B.
danh...@millcomm.com
In <5vs5c8$5...@news.acns.nwu.edu>, ka...@sludge.phys.nwu.edu (R. Kalia) writes:
>As for maintenance, the pilot needs a thermocouple in it to detect that the
>flame is on (safety precaution; furnace won't send gas to burners unless
>pilot is lit) The thermocouple needs to be changed every couple of years
>(the maintenance people like to change it every year, but that's probably
>not strictly necessary).
There's really no need to replace a thermocouple until it fails, and most
will last ten years or longer. (Though there are a few designs that
apparently "eat" thermocouples.)
Dan Hicks
Hey!! My advice is free -- take it for what it's worth!
http://www.millcomm.com/~danhicks
Terry Kennedy
In alt.home.repair sh...@freenet.edmonton.ab.ca wrote:
> WHOA!!! Did you just say EVERY COUPLE of years, re: changing thermocouple?
> My Lennox thermocouple failed after, would you believe, 15 months????
> At the time, since the furnace was almost brand new, I panicked and
> assumed that there had to be a complicated reason for the "no heat"
> condition.
All this new stuff sounds like it has lots more problems than the old stuff
it replaced. In the house I grew up in, we have a Bryant gas-fired baseboard
hot water system [installed in 1966 when the house was built] and the only
things that ever went wrong with it were the circulating pump and one of the
zone valves. The only service ever done on it besides the above was vacuuming
out the dog fur every 4 or 5 years while we had a dog. It's still going strong
31 years later.
Terry Kennedy Operations Manager, Academic Computing
te...@spcvxa.spc.edu St. Peter's College, Jersey City, NJ USA
+1 201 915 9381 (voice) +1 201 435-3662 (FAX)ch
John Mills
> The install was done in fall, 1993. Last week, when the furnace came on
> for the first time this heating season, it took 3 tries before the
> thermocouple detected flame. Since then it has be OK...without any
> cleaning.
What do you mean 3 tries before it detected flame? So the pilot was out,
then you lit it and after waiting a minute, released the button and
the pilot went out and you had to do this 3 times before the pilot
stayed lit?
lda...@*no_spam*roanoke.infi.net
Quoth tomja...@tomjwatson.ibm.com:
>
>Does any gas furnace manufacturer make one with a pilot light?
>one includes the added costs of electricity and repairs (? - I'm
>assuming an ignition system is more likely to fail than a pilot)?
>
>
>Thanks.
My old furnace had a standing pilot. Condensation of water vapor from
the pilot flame rusted a hole in the heat exchanger... not the only
reason I replaced the furnace, but one of them.
The new one has a hot surface ignitor, very similar to the one that my
gas clothes dryer uses. The dryer is probably at least 15 years old
(we've lived in the house for 12 years and it was here when we bought
the house), and the dryer is used 12 months a year. It has its
original ignitor. The pilot on the old furnace would occasionally go
out because of a buildup of ash or something on the thermocouple -
easy to fix, but a bit of a nuisance.
To reply by email, delete the *NO_SPAM* from my email address.
sh...@freenet.edmonton.ab.ca
John Mills (jmm...@in.net) wrote:
: > The install was done in fall, 1993. Last week, when the furnace came on
No. It is the one of the newer models with no pilot. The design allows
for 3 tries at ignition, then it locks out further attempts for about an
hour--to allow dissipation of accumulated gas, I presume. Now, in reality,
it did light after the first attempt..but the thermocouple did not
actually detect flame until the third attempt. Wondering if the
thermocouple developed an oxide coat over the summer season that burned
off during the first 2 attempts????
: --
: Visit me!
: http://www.geocities.com/~johnmills
--
David B
David B. replies sheepishly:
I don't recall the specifics, since we sold the house and left all the maintenance and
service records with the new owners. I'm fairly handy with mechanical repairs, but not
knowing much about electronics parts on fancy furnaces, I had no choice but to call the
service tech. And again, it was an "after hours" (read: more expensive) call, since I
didn't feel like waiting until Tuesday morning for heat. The bill wasn't itemized, and
now I think I know why. I seem to recall the tech saying something about a flat fee
including parts and labor for this type of repair. I just felt lucky that I was able to
get him to come out the same night and fix it. The owner of the HVAC company actually
went to the warehouse and then met the tech at my house with the part. I think I paid
around $100, maybe a little more or less.
R. Kalia
In article <EGsx1...@spcuna.spc.edu>, te...@spcuna.spc.edu says...
>
>In alt.home.repair sh...@freenet.edmonton.ab.ca wrote:
>> WHOA!!! Did you just say EVERY COUPLE of years, re: changing thermocouple?
>
> All this 'new stuff' sounds like it has lots more problems than the old
But thermocouples are not new stuff. They're 'old stuff', You cannot have a
gas pilot without one.
Terry Kennedy
In alt.home.repair R. Kalia <ka...@sludge.phys.nwu.edu> wrote:
> But thermocouples are not new stuff. They're 'old stuff', You cannot have a
> gas pilot without one.
a) I was referring to the "NASA launch control" style of wiring in new units
compared to the old reliable units of years back.
b) Not sure what you're referring to by a thermocouple. A thermocouple is
a device which generates a small electrical signal proportional to
changing temperature. I can tell you that the hot water heater (next to
the Bryant furnace I mentioned in my previous post) has abolutely no
electrical parts in it, and the Bryant furnace works fine (with gravity
circulation and the zone valves open) when the power is off - in fact,
last winter I ran it that way for a day when the power was off in Ring-
wood. The voltage generated by a thermocouple is _way_ too small to
operate any sort of valve for the gas and would have to be used to con-
trol some electronics, which neither gas unit has. Another way to shut
down a gas appliance when the pilot fails would be a bimetallic strip,
which flexes when heated. *That* has enough force to be able to close
the valve that controls the pilot light - a "start" button would hold
the strip in the heated position, allowing gas to enter the pilot. When
you lit the pilot, the strip would flex on its own and you could let go
of the start button. If the pilot went out, the strip would flatten out
and close the pilot valve.
David
The voltage generated by a thermocouple DOES actually operate the
solenoid in a gas valve. It is a high turn coil with thousands of turns
of hair thin enamel wire. Your gas water heater has such a gas valve if
it has a pilot and the same system is commonly used in a furnace. When
I was a teenager, I tried to argue the same point with my dad (who
eventually spent 50 years in the HVAC business before his death) and he
brought home a gas valve and thermocouple for a demonstration. BTW, if
your Bryant furnace is a forced air unit and you cheated the system, you
built up quite a bonnet temperature when you ran it with power off.
That could be a terrific fire hazard.
Dan Lanciani
In article <EGwJx...@spcuna.spc.edu>, te...@spcuna.spc.edu (Terry Kennedy) writes:
| In alt.home.repair R. Kalia <ka...@sludge.phys.nwu.edu> wrote:
| > But thermocouples are not new stuff. They're 'old stuff', You cannot have a
| > gas pilot without one.
|
| a) I was referring to the "NASA launch control" style of wiring in new units
| compared to the old reliable units of years back.
And of course it's even worse in that the condensing units have an equally
complex maze of tubes in addition to the wiring. My installer managed to
mis-configure said tubes the first time. Later, one of them dissolved. :(
Worse still, the local gas company (with whom we had a service contract for
some time) is afraid to touch these complicated units.
| b) Not sure what you're referring to by a thermocouple. A thermocouple is
| a device which generates a small electrical signal proportional to
| changing temperature. I can tell you that the hot water heater (next to
| the Bryant furnace I mentioned in my previous post) has abolutely no
| electrical parts in it, and the Bryant furnace works fine (with gravity
| circulation and the zone valves open) when the power is off - in fact,
| last winter I ran it that way for a day when the power was off in Ring-
| wood. The voltage generated by a thermocouple is _way_ too small to
| operate any sort of valve for the gas and would have to be used to con-
| trol some electronics, which neither gas unit has.
Much as I hate to disagree with Terry on almost any subject, thermopile
systems that do exactly this (control a gas valve directly) have existed
for years. Look in any HVAC catalog under "millivolt controls" and you
should still find the parts. My house's original (1959) furnace used
just such a system to control the main gas valve. It was pretty neat to
watch (really hear since you couldn't see it move) that big valve open
powered only by the little pilot's thermocouple. It was also a reliable
system, though it did require some maintenance. In particular, since the
voltage is *so* low, any corrosion at the terminals of the thermostat,
valve, or emergency shutoff switch could cause enough resistance to make
the system at least sluggish (valve doesn't open until minutes after thermostat
kicks on). A good cleaning every few years was in order and sometimes
a new thermostat or switch was necessary. About every ten years the solenoid
and/or pile needed to be replaced. (I suspect they could have been reworked,
but since the contract covered parts...) Unfortunately, about five years
ago, exact parts for my particular furnace became hard for the gas company
service folks to get and they started making substitutions. They used a
generic thermopile with "higher" voltage output (but possibly less current
capacity) that didn't really fit fully in the pilot. They "bypassed" the
emergency shutoff switch to reduce voltage loss. Things generally went
down hill from there even though they replaced the gas valve with one that
ostensibly matched the pile. (I still have the newish parts in a box
somewhere.) Anyway, although it probably would have been possible to
find a combination of generic replacements that worked, I eventually
broke down and had a new furnace installed. At the time I looked for a
model with a standing pilot, but had little luck. I've already had to
replace parts on the new fancy furnace. Sigh.
|Another way to shut
| down a gas appliance when the pilot fails would be a bimetallic strip,
| which flexes when heated. *That* has enough force to be able to close
| the valve that controls the pilot light - a "start" button would hold
| the strip in the heated position, allowing gas to enter the pilot. When
| you lit the pilot, the strip would flex on its own and you could let go
| of the start button. If the pilot went out, the strip would flatten out
| and close the pilot valve.
I have heard of that system, but I've never seen it used. Every gas water
heater that we have owned uses the thermopile system. Since water heaters
have not yet made the transition to computer control, you even see the
replacement parts in places like Home Depot. Are you sure yours is not
electric? The connection from the thermocouple to the gas control looks
like a small copper tube (complete with screw fitting on the end) but it
is really a coaxial conductor. Because the water heater has no external
control wiring to introduce resistance, and since the pilot generator needs
only to hold the valve open (manual start) as opposed to moving it, the
application is almost trivial compared to the furnace magic.
Dan Lanciani
ddl@harvard.*
danh...@millcomm.com
In <EGwJx...@spcuna.spc.edu>, Terry Kennedy <te...@spcuna.spc.edu> writes:
> b) Not sure what you're referring to by a thermocouple. A thermocouple is
> a device which generates a small electrical signal proportional to
> changing temperature. I can tell you that the hot water heater (next to
> the Bryant furnace I mentioned in my previous post) has abolutely no
> electrical parts in it, and the Bryant furnace works fine (with gravity
> circulation and the zone valves open) when the power is off - in fact,
> last winter I ran it that way for a day when the power was off in Ring-
> wood. The voltage generated by a thermocouple is _way_ too small to
> operate any sort of valve for the gas and would have to be used to con-
> trol some electronics, which neither gas unit has.
Sorry, but you're wrong. The thermocouple puts out enough juice to
operate a small solenoid valve for the pilot inside the control valve.
Some gravity hot air gas furnaces ("millivolt" systems) even use the juice
from the thermocouple to operate the main gas valve.
Terry Kennedy
In alt.home.repair David <d.pri...@NOSPAMworldnet.att.net> wrote:
> brought home a gas valve and thermocouple for a demonstration. BTW, if
> your Bryant furnace is a forced air unit and you cheated the system, you
> built up quite a bonnet temperature when you ran it with power off.
> That could be a terrific fire hazard.
It's baseboard hot water. It's not "cheated" at all - in fact, the info
for operating it during power failures is one of the things on the aluminum
faceplate (along with pilot lighting info, ratings, etc.).
p...@net.com
danh...@millcomm.com wrote:
>>> wood. The voltage generated by a thermocouple is _way_ too small to
>> operate any sort of valve for the gas and would have to be used to con-
>> trol some electronics, which neither gas unit has.
>
>Sorry, but you're wrong. The thermocouple puts out enough juice to
>operate a small solenoid valve for the pilot inside the control valve.
>Some gravity hot air gas furnaces ("millivolt" systems) even use the juice
>from the thermocouple to operate the main gas valve.
Sorry Dan, but "your" wrong. The original poster is cooreect. Your
are confusing a thermocouple and thermopile. Get it right!
Topher Eliot
> b) Not sure what you're referring to by a thermocouple. A thermocouple is
> a device which generates a small electrical signal proportional to
> changing temperature. I can tell you that the hot water heater (next to
> the Bryant furnace I mentioned in my previous post) has abolutely no
> electrical parts in it, and the Bryant furnace works fine (with gravity
> circulation and the zone valves open) when the power is off - in fact,
> last winter I ran it that way for a day when the power was off in Ring-
> The voltage generated by a thermocouple is _way_ too small to
> operate any sort of valve for the gas and would have to be used to con-
> trol some electronics, which neither gas unit has.
My parents' furnace uses absolutely no electricity supply; the hot air
is gravity-driven. But they have a mercury-bulb thermostat upstairs
that manages to turn the furnace in the basement on and off. I recall
hearing that it is a "millivolt" system. I'm under the impression
that the minute amount of electricity used is in fact generated by the
thermocouple in the pilot light flame. Any other theories out there?
Topher Eliot
el...@alum.mit.edu
Visit the house maintenance archive at http://www.geocities.com/heartland/7400
