This group is knowledgeable about so many topics I though I'd ask
about a problem I'm having with a Trane high efficiency (condensing,
model TUX080) furnace installed in my house. Every once in a while,
the furnace gets stuck in the cool-down part of the heat cycle wherein
the flame is out and the blower keeps running until the microprocessor
is manually reset by turning the power off/on. This is particularly
annoying when it happens in the middle of a cold night as it's usually
discovered because the house gets cold and one has to get up to reset
it. The processor is flashing an error message but, with the help of
the dealer, I've checked out the suggested fault possibilities to no
avail (ignitor, voltage level or grounding problem).

Anyhow, the dealer also mentioned that line voltage noise and spikes
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

Another possibility I don't want to think about is an intermittant
processor board problem (a replacement board is nearly $500 CAN with
no assurance that it will correct the problem).

TIA for any help............


Laurie Forbes

For furnace problems related to safety, reliability and potentially
expensive repairs (without any assurance that the problem will definitely be
solved - called guesswork), it's best to get diagnostic information directly
frm the manufacturer. Try contacting a Trane National Service Manager.. it's
his/her responsibility to take care of problems like yours.
Dealers don't always have the latest technical information.

On the topic of surges and spikes on the line.. if there are any other
motorized or high current appliances (such as a freezer) on the same circuit
as the furnace, this can cause line voltage lags and spikes as it cycles
on/off.

A furnace with a microprocessor controller should have some (maybe minimal)
protection from line voltage problems.
If it was certain that voltage spikes were the cause, individual suppressors
could be installed across the line-ground (and neutral-ground) connections
where the AC voltage enters the furnace.
These are small inexpensive devices with 2 leads that can be wired into the
furnace's power terminals. These are the same supressors found in most surge
supressor power strips.

WB
................

"Laurie Forbes" wrote in message
...
This group is knowledgeable about so many topics I though I'd ask
about a problem I'm having with a Trane high efficiency (condensing,
model TUX080) furnace installed in my house. Every once in a while,
the furnace gets stuck in the cool-down part of the heat cycle wherein
the flame is out and the blower keeps running until the microprocessor
is manually reset by turning the power off/on. This is particularly
annoying when it happens in the middle of a cold night as it's usually
discovered because the house gets cold and one has to get up to reset
it. The processor is flashing an error message but, with the help of
the dealer, I've checked out the suggested fault possibilities to no
avail (ignitor, voltage level or grounding problem).

Anyhow, the dealer also mentioned that line voltage noise and spikes
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

Another possibility I don't want to think about is an intermittant
processor board problem (a replacement board is nearly $500 CAN with
no assurance that it will correct the problem).

TIA for any help............


Laurie Forbes

On Fri, 17 Oct 2003 04:57:08 GMT, am (Laurie Forbes) wrote:
Anyhow, the dealer also mentioned that line voltage noise and spikes
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

Microcenter (computer retailer) recently had 300 watt UPS units on
sale for $19.95. That's cheaper than replacement batteries, which
my old UPS needed. I bought 1, then went back and bought 2 more
before the sale ended. They work great, and have excellent built in
suppression. Being UPSs, they would keep the uP control from
losing its settings during short power failures too.

So if the problem really is glitches on the line, I'd recommend
something like this. My furnace controls already have a switch
and receptacle feeding the control transformer (required by Code
for crawl space furnaces), so it would be the work of but moments
to add one of these UPSs.

Gary

On Fri, 17 Oct 2003 03:53:44 -0400, "Wild Bill" wrote:
If it was certain that voltage spikes were the cause, individual suppressors
could be installed across the line-ground (and neutral-ground) connections
where the AC voltage enters the furnace.

Also one line to line for differential surge. The two you describe only clamp
common mode surge.

These are small inexpensive devices with 2 leads that can be wired into the
furnace's power terminals. These are the same supressors found in most surge
supressor power strips.

Except that good surge suppressor power strips also have inductor capacitor
low pass filters as well as the MOVs.

Gary

am (Laurie Forbes) wrote in message ...
This group is knowledgeable about so many topics I though I'd ask
about a problem I'm having with a Trane high efficiency (condensing,
model TUX080) furnace installed in my house. Every once in a while,
the furnace gets stuck in the cool-down part of the heat cycle wherein
the flame is out and the blower keeps running until the microprocessor
is manually reset by turning the power off/on. This is particularly
annoying when it happens in the middle of a cold night as it's usually
discovered because the house gets cold and one has to get up to reset
it. The processor is flashing an error message but, with the help of
the dealer, I've checked out the suggested fault possibilities to no
avail (ignitor, voltage level or grounding problem).

Anyhow, the dealer also mentioned that line voltage noise and spikes
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

Another possibility I don't want to think about is an intermittant
processor board problem (a replacement board is nearly $500 CAN with
no assurance that it will correct the problem).

TIA for any help............


Laurie Forbes

You can get EMI suppressor or filter modules on the surplus market,
they're rated by amperage or wattage. I used to get them from the
local electronic surplus dealer, they've folded up shop, though. The
one I have is in a flat, square tin can, two isolated teminals in, two
out, can is the common ground. Ran about $6 and was easy to get wired
up in line with the mini-lathe motor controller. Hash from that was
driving my computer UPS nuts.

In Canada, I have no idea who would be a supplier. In the US,
Digi-Key and Mouser would be starting places for new ones, Gateway
Electronics and All Electronics are two web suppliers that might have
them periodically as surplus. Some types are from PC power supplies
and have the common appliance cord receptacle, others are strictly a
permanent wire-in solution. These eliminate EMI from other sources
but don't deal with dips in line voltage or brown-out conditions. For
those conditions, a ferro-resonant transformer would be needed, Sola
is one brand that shows up on the surplus market.

Having had to replace a controller board on my furnace, I can
emphathize. Lots of money for not a whole lot of technology on it.

Stan

am (Laurie Forbes) wrote in message ...
This group is knowledgeable about so many topics I though I'd ask
about a problem I'm having with a Trane high efficiency (condensing,
model TUX080) furnace installed in my house. Every once in a while,
the furnace gets stuck in the cool-down part of the heat cycle wherein
the flame is out and the blower keeps running until the microprocessor
is manually reset by turning the power off/on. This is particularly
annoying when it happens in the middle of a cold night as it's usually
discovered because the house gets cold and one has to get up to reset
it. The processor is flashing an error message but, with the help of
the dealer, I've checked out the suggested fault possibilities to no
avail (ignitor, voltage level or grounding problem).

Anyhow, the dealer also mentioned that line voltage noise and spikes
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

Another possibility I don't want to think about is an intermittant
processor board problem (a replacement board is nearly $500 CAN with
no assurance that it will correct the problem).

TIA for any help............


Laurie Forbes

Since it gets stuck in the same state each time, could be a "self
induced" power spike rather than an external one. For example, the
spikes resulting when the control board actuates the draft motor, the
gas solenoid or the fan motor. The draft motor comes to mind first as
its "off" spike happens when the furnace cycles off - with the fan
still running until it cools down.

Are there any accessories wired into the system, like an electronic
air cleaner or humidifier? Might try disconnecting those before
messing with the furnace.

There are a bunch of sensors in that style furnace - flame sensor,
over-temp sensor, draft sensor, I don't know what else. Takes only
one to make it stop working, but your description of the problem
indeed does not sound like a sensor related problem.

If you have A/C (or a heat pump), dirty evaporator coils can reduce
air flow to where the furnace shuts off on the over-temp. Dirty or
wet combustion supply air can clog or corrode the burners to where not
all will light and it shuts off on account of the flame sensor.
These are examples of things you can fix yourself with a suitable
shape brush.

Bob

Thanks everyone for your replies to my query.

I've emailed Trane but have as of yet not received a reply so, I have
gone ahead anyway and installed a Trip-Lite surge suppressor (3500
Joules) and now have a plug-in furnace. Due mainly to the exhorbitant
cost of a new processor board (not much technology or componentry for
the price indeed), I felt a surge suppressor was required in any case,
no matter what else may be wrong with the thing.

The Trip-Lite also has coax and phone line suppression just in case I
want to connect my furnace to the internet

In regards to the suggestion for a UPS, I do have a spare 300 Watt
unit but decided against trying it as it does not have sine wave
output and I question whether 300 Watts is enough to power the blower
motor plus all the other stuff.

I considered wiring the Trip-Lite directly into the breaker box to
eliminate a junction point but am probably challenging the electrical
code enough as is, what with a plug-in furnace, so decided not to.

Now, to wait and see what happens.............

Laurie Forbes

Thanks everyone for your replies to my query.

I've emailed Trane but have as of yet not received a reply so, I have
gone ahead anyway and installed a Trip-Lite surge suppressor (3500
Joules) and now have a plug-in furnace. Due mainly to the exhorbitant
cost of a new processor board (not much technology or componentry for
the price indeed), I felt a surge suppressor was required in any case,
no matter what else may be wrong with the thing.

The Trip-Lite also has coax and phone line suppression just in case I
want to connect my furnace to the internet

In regards to the suggestion for a UPS, I do have a spare 300 Watt
unit but decided against trying it as it does not have sine wave
output and I question whether 300 Watts is enough to power the blower
motor plus all the other stuff.

I considered wiring the Trip-Lite directly into the breaker box to
eliminate a junction point but am probably challenging the electrical
code enough as is, what with a plug-in furnace, so decided not to.

Now, to wait and see what happens.............

Laurie Forbes

On Sat, 18 Oct 2003 00:39:20 GMT, am (Laurie Forbes) wrote:
In regards to the suggestion for a UPS, I do have a spare 300 Watt
unit but decided against trying it as it does not have sine wave
output and I question whether 300 Watts is enough to power the blower
motor plus all the other stuff.

It wouldn't be able to run the blower etc. I was suggesting hooking it up
to feed the control transformer, and control, only. But if it is a square wave
inverter, I wouldn't use it for that either.

Gary

On Sat, 18 Oct 2003 17:54:36 GMT, (Gary Coffman)
wrote:

On Sat, 18 Oct 2003 00:39:20 GMT, am (Laurie Forbes) wrote:
In regards to the suggestion for a UPS, I do have a spare 300 Watt
unit but decided against trying it as it does not have sine wave
output and I question whether 300 Watts is enough to power the blower
motor plus all the other stuff.

It wouldn't be able to run the blower etc. I was suggesting hooking it up
to feed the control transformer, and control, only. But if it is a square wave
inverter, I wouldn't use it for that either.


Are there UPSs in the 2 or 3 hundred Watt range available with sine
wave output??


Laurie Forbes

If it plugs in - likely - just put in a strip - the power strips that
are protected - and maybe a breaker for safety. Other than that,
it is make it yourself type.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

This group is knowledgeable about so many topics I though I'd ask
about a problem I'm having with a Trane high efficiency (condensing,
model TUX080) furnace installed in my house. Every once in a while,
the furnace gets stuck in the cool-down part of the heat cycle wherein
the flame is out and the blower keeps running until the microprocessor
is manually reset by turning the power off/on. This is particularly
annoying when it happens in the middle of a cold night as it's usually
discovered because the house gets cold and one has to get up to reset
it. The processor is flashing an error message but, with the help of
the dealer, I've checked out the suggested fault possibilities to no
avail (ignitor, voltage level or grounding problem).

Anyhow, the dealer also mentioned that line voltage noise and spikes
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

Another possibility I don't want to think about is an intermittant
processor board problem (a replacement board is nearly $500 CAN with
no assurance that it will correct the problem).

TIA for any help............


Laurie Forbes
As an afterthought... Even though you "checked the
grounds", you may want to go over them again.
Remove the ground connections, clean the metal
and all areas that need to be grounded, then
re-attach and make sure they are secure. Grounding
on this type of equipment can be critical and even
though they may seem snug, cleaning and re-doing
them may solve your problem.
Ken.

On Sun, 19 Oct 2003 01:50:32 GMT, am (Laurie Forbes) wrote:
Are there UPSs in the 2 or 3 hundred Watt range available with sine
wave output??

Yeah.

Gary

In article , Kenneth W. Sterling wrote:
This group is knowledgeable about so many topics I though I'd ask
about a problem I'm having with a Trane high efficiency (condensing,
model TUX080) furnace installed in my house. Every once in a while,
the furnace gets stuck in the cool-down part of the heat cycle wherein
the flame is out and the blower keeps running until the microprocessor
is manually reset by turning the power off/on. This is particularly
....
can also glitch the processor so I am thinking of installing a surge
suppressor in the line input. One way would be to use a suppressor
typically used for electronic equipment such as computers but they are
plug in rather than permanent wired. Any comments on using such a
device (by installling a plug in the furnace line and plugging it into
the suppressor) would be appreciated, or, any other suggestions.

most furnaces _do_ have a plug, maybe you should check your local
code, hardwiring would be an unusual requirement. more likely the
code calls for a certain grade/type connector/jack and the electrician
saved time/money by hard wiring.

wrt to the spike arrestors, they probably won't help much. a ferrups
xmfr would be my choice. use both if you want. --Loren


Another possibility I don't want to think about is an intermittant
processor board problem (a replacement board is nearly $500 CAN with
no assurance that it will correct the problem).

TIA for any help............


Laurie Forbes
As an afterthought... Even though you "checked the
grounds", you may want to go over them again.
Remove the ground connections, clean the metal
and all areas that need to be grounded, then
re-attach and make sure they are secure. Grounding
on this type of equipment can be critical and even
though they may seem snug, cleaning and re-doing
them may solve your problem.
Ken.

Yes, there are but you really don't need one for this application.
I'd first see if Trane has a fix for the microprocessor problem as they
probably forgot the "lost in space" rebooter circuit when they built them
and are now finding they blew it.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works evevery time it is tried!

On Sun, 19 Oct 2003 13:10:33 -0700, "Bob May"
wrote:

Yes, there are but you really don't need one for this application.
I'd first see if Trane has a fix for the microprocessor problem as they
probably forgot the "lost in space" rebooter circuit when they built them
and are now finding they blew it.

--

I've emailed them but have not yet received a reply - we'll see I
guess.

There's a certain irony to this - one buys a high efficiency furnace
to save on heating bills and then may have to spend 500 bucks three
years later on a $50 circuit board. My old furnace would never have
had such a problem.


Laurie Forbes