Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

On Sat, 10 Jan 2004 18:12:43 -0800, Gunner wrote
(in message ):

Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

My long distance guess: Bad gas solenoid. Second possibility, the contact
in the controller that feeds the gas solenoid is burned.

Hope this helps.

Roger in Vegas
Worlds Greatest Impulse Buyer

My best guess from my chair and with a little hands on experience with
controlers that your problem is your flame sensor. If my memory serves me
correctly you can take a 1.5 volt battery with a 15K ohm resistor in series
and bypass the flame sensor . This will confirm the flame sensor function .

I have seen some of these problems in the past caused by open inspection
plates that allows drafts to blow the flame askew and by debris on the flame
holder that slighly deflect the flame.... all worth looking at.

good luck.



"Gunner" wrote in message
...
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

On Sun, 11 Jan 2004 02:12:43 GMT, the renowned Gunner
wrote:

Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

That's my guess too, I don't think the flame rod could cause that kind
of problem (but I'm coming at it from the other side..). Check the
24VAC at the controller- make sure it's in the right range and fairly
steady as the gas valve is energized.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Gunner wrote:
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.


The blower unit worked OK, but did they actually hook it to a gas valve?
Or, did they just hook a meter to the gas valve terminals? That might
not be a good enough test. Assuming an AC gas solenoid, they probably
use a triac (SSR) to drive the gas valve. These can have all manner
of odd failure modes. You should hook a DVM to the solenoid leads,
and see if the 24 V AC is going on and off. If so, it is the control.
If a stady 24 V AC is going to the solenoid, then it is the solenoid valve
that is bad. You can also connect the solenoid valve to 24 V AC and see
if it holds steadily or clatters.


Jon

On Sun, 11 Jan 2004 03:13:07 GMT, Spehro Pefhany
wrote:

On Sun, 11 Jan 2004 02:12:43 GMT, the renowned Gunner
wrote:

Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

That's my guess too, I don't think the flame rod could cause that kind
of problem (but I'm coming at it from the other side..). Check the
24VAC at the controller- make sure it's in the right range and fairly
steady as the gas valve is energized.

24vac is steady on input, but flakes out to the gas solenoid during
the ignition sequence. I removed the coil from the solenoid from the
circuit, thinking there was perhaps a short, ohmed it out, ok, refired
the system and the 24vts still only fired for a second or so without
the solenoid in the circuit. I would automaticly replace the
controller, but the boss indicated it worked fine at the dealers so it
should work fine yada yada yada... shrug.

Gunner


This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

Best regards,
Spehro Pefhany

"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

On Sat, 10 Jan 2004 18:30:17 -0800, Roger Hull
wrote:

On Sat, 10 Jan 2004 18:12:43 -0800, Gunner wrote
(in message ):

Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

My long distance guess: Bad gas solenoid. Second possibility, the contact
in the controller that feeds the gas solenoid is burned.

the controller is a sealed unit, containing what I believe are solid
state switches. I was unable to feel even the slightest TICK when the
ignition sequence would fire.

Gunner


Hope this helps.

Roger in Vegas
Worlds Greatest Impulse Buyer

"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

"Gunner" wrote in message
...
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Turn off the gas, turn of the power, wire the solenoid directly to the
transformer, turn on the power. Does the solenoid hold in? If not it's a
bad transformer or solenoid. If it does your flame sensor is bad. My bet
is a bad winding in the solenoid or transformer that shorts or opens under
its own induced field.

Loyd

On Sun, 11 Jan 2004 01:05:22 -0500, "Blake Loyd"
wrote:


"Gunner" wrote in message
.. .
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Turn off the gas, turn of the power, wire the solenoid directly to the
transformer, turn on the power. Does the solenoid hold in? If not it's a
bad transformer or solenoid. If it does your flame sensor is bad. My bet
is a bad winding in the solenoid or transformer that shorts or opens under
its own induced field.

Loyd

Blink blink..ok....Ill try that. Ill also try that with the gas on at
the appropriate time in the ignition cycle and see if the flame rod
ever stablizes or has a rectification.

I hate working with electrically operated natural gas devices that use
a 1" gas line. Ive lost my eyebrows more than once...

Gunner

"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

Hey Gunner,

I have a mid-efficiencey ( electronic control similar to yours)
natural gas FAG in the crawl space in the new place here. So I can't,
in my physical state, "get at it" like I could maybe 20 years back.
Anyway, with-out suggesting mine had the identical problem, I can say
that it was somewhat similar. My furnace guy said "Well, do you want
to, spend $280 or just an hour service call?". Gee, guess what I
picked?!? Anyway, he took out the flame sensor gadget, cleaned it off
(it didn't look real dirty to me by the way) and it has run OK up to
this point. So I'd try that if I were you.

One other thought because I'm not sure what you meant. A test like
this of a quick acting or short term electrical occurrence is easier
to see with an analog VOM then one of the contemporary digital types.

Take care. Good Luck.

Brian Lawson,
Bothwell, Ontario.

ps.... At the 0 degree F temps here the past few days, my furnace is
running about 20 minutes per hour in the day time. On and off about 4
times per hour for about 5 minutes each time. Don't know about
night-time, and it's on a "set-back" anyway. hate to see the next gas
bill.
XXXXXXXXXXXXXXXXXXXXXXX
On Sun, 11 Jan 2004 02:12:43 GMT, Gunner
wrote:

Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

On Sun, 11 Jan 2004 06:24:36 GMT, Gunner
brought forth from the murky depths:

I hate working with electrically operated natural gas devices that use
a 1" gas line. Ive lost my eyebrows more than once...

Silly wabbit. Try one of these next time, eh?
http://www.harborfreight.com/cpi/cta...emnumber=46526

--
Vidi, Vici, Veni
---
http://diversify.com Comprehensive Website Development

"Gunner" wrote in message
...
On Sun, 11 Jan 2004 01:05:22 -0500, "Blake Loyd"
wrote:


"Gunner" wrote in message
.. .
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Turn off the gas, turn of the power, wire the solenoid directly to the
transformer, turn on the power. Does the solenoid hold in? If not it's
a
bad transformer or solenoid. If it does your flame sensor is bad. My
bet
is a bad winding in the solenoid or transformer that shorts or opens
under
its own induced field.

Loyd

Blink blink..ok....Ill try that. Ill also try that with the gas on at
the appropriate time in the ignition cycle and see if the flame rod
ever stablizes or has a rectification.

I should have said the flame sensor circuit/system.
Now, I am assuming that you haven't changed out the controller, because
if you have and you have an external purge timer you just need to read the
installation instructions regarding that situation.
I am also assuming that the controller hasn't gotten wet as that could
cause problems.
That said, maybe this will be clearer.

Turn off the gas. Turn off the power.
Check the flame sensor wire to make sure it is not damaged and that it isn't
touching anything to which it can ground out. If it appears ok then check
the following.
Mark the wires so you can reconnect them in the same manner as switching
leads may cause the system to lock out. Disconnect the secondary of the
transformer from everything. Disconnect the gas valve. Wire the transformer
directly to the gas valve solenoid. Turn on the power.
Does the gas valve open and stay open or does it chatter(open close open
close open etc)?
If it opens and stays open the transformer and valve are fine.
If it chatters then one or the other is bad. Since you say the 24V is
constant it is apparently the solenoid.
If the transformer and gas valve solenoid are good then the problem lies
in the flame detection system/circuit.
Turn off the power.
Rewire the transformer and gas valve as they were originally. Loosen and
retighten the flame sensor mounting screw. See if that solves the
problem(bad ground). If not, remove the flame sensor, disconnect it from
the controller at the controller, attach meter to lead end disconnected from
controller and base of sensor(ground), heat sensor with a propane torch to
see if it produces the 0.8uA minimum through the lead.
If it doesn't, disconnect the lead from the sensor and test the sensor
again to see if it produces the 0.8uA minimum. If it does the lead is bad.
If it doesn't the sensor is bad.
If both check out as working properly and you are confident that the
moving of the lead hasn't just happened to alleviate a ground in the lead,
then the problem lies in the controller(unless you did alleviate a ground in
the sensor lead).
From your description of what's going on it sounds as if the problem
lies in the solenoid circuit. It could be the solenoid or it could be the
controller isn't holding in the solenoid circuit. Since it happens during
the start-up I doubt it is the flame sensor. I guess is that it is the
solenoid or the controller.

Loyd

In article , Blake Loyd says...

... remove the flame sensor, disconnect it from
the controller at the controller, attach meter to lead end disconnected from
controller and base of sensor(ground), heat sensor with a propane torch to
see if it produces the 0.8uA minimum through the lead.
If it doesn't, disconnect the lead from the sensor and test the sensor
again to see if it produces the 0.8uA minimum. If it does the lead is bad.
If it doesn't the sensor is bad.

In this case, is the flame sensor a thermocouple?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

On 11 Jan 2004 12:03:07 -0800, the renowned jim rozen
wrote:

In article , Blake Loyd says...

... remove the flame sensor, disconnect it from
the controller at the controller, attach meter to lead end disconnected from
controller and base of sensor(ground), heat sensor with a propane torch to
see if it produces the 0.8uA minimum through the lead.
If it doesn't, disconnect the lead from the sensor and test the sensor
again to see if it produces the 0.8uA minimum. If it does the lead is bad.
If it doesn't the sensor is bad.

In this case, is the flame sensor a thermocouple?

These units use a rod sitting out in the open flame. They sense the
rectifying action of a flame, which is very insensitive to soot
contamination or other undesired side effects. Needless to say, a
false positive flame detection would be a very serious matter. Flame
out, gas valve stays open, ssssssssssssssssssssssssssss, mixing with
air, seeping out, searching, until it finds *another* flame, anywhere.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Gunner" wrote in message
...
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

What's the gas pressure to the unit? I installed a new furnace a few years
ago that wouldn't fire the main burner. Turned out the pressure was slightly
higher than the valve could take. Old furnace worked fine for many years at
the same pressure....Paul

"PJ" wrote in message
...

"Gunner" wrote in message
...
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

What's the gas pressure to the unit? I installed a new furnace a few years
ago that wouldn't fire the main burner. Turned out the pressure was
slightly
higher than the valve could take. Old furnace worked fine for many years
at
the same pressure....Paul


Your question brings up other issues.
I'd assumed it was a piece of equipment that was already in use.
Is the equipment new? Had it been working and stopped? Had repairs
been done to it recently and if so what?
Your point about the gas pressure is a good one, especially if the
equipment is new or the gas valve has been changed.

Loyd

On 11 Jan 2004 12:03:07 -0800, jim rozen
wrote:

In article , Blake Loyd says...

... remove the flame sensor, disconnect it from
the controller at the controller, attach meter to lead end disconnected from
controller and base of sensor(ground), heat sensor with a propane torch to
see if it produces the 0.8uA minimum through the lead.
If it doesn't, disconnect the lead from the sensor and test the sensor
again to see if it produces the 0.8uA minimum. If it does the lead is bad.
If it doesn't the sensor is bad.

In this case, is the flame sensor a thermocouple?

Jim

No..the flame rod is a device that puts 100 or so volts on the flame
rod, which is exposed to the flame, and uses flame rectification to
convert this to dc and then to ground. It senses the ground path

Gunner

================================================= =
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
================================================= =

"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

In article , Gunner says...

...the flame rod is a device that puts 100 or so volts on the flame
rod, which is exposed to the flame, and uses flame rectification to
convert this to dc and then to ground. It senses the ground path

Thanks, I've learned something today. I've never
seen those, all the flame decectors I've been aware
of are either thermocouples or CdS photocells.

Also the SiC ignitor modules in our oven - which always
seem to burn out at the *worst* time!

Jim

==================================================
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JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
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In article , Blake Loyd says...
[about a Honeywell gas control...]
... remove the flame sensor, disconnect it from
the controller at the controller, attach meter to lead end disconnected
from
controller and base of sensor(ground), heat sensor with a propane torch
to
see if it produces the 0.8uA minimum through the lead.

On Sun, 11 Jan 2004 20:25:15 GMT, Spehro Pefhany
wrote:

[I think as a reply to the above, but I want to check if that is true or
not...]

These units use a rod sitting out in the open flame. They sense the
rectifying action of a flame, which is very insensitive to soot
contamination or other undesired side effects.

I have a "Seahorse" heater with a Honeywell VR8204M control that uses one
of those. I could never measure any self-generated output from it, and was
under the impression that it rectified power supplied by the controller
rather than sourcing its own thermopile current. Is that what you are
saying here?

Is there some way to test those with multimeter, maybe while they are
connected to their controllers?

My problem turned out to be that the pilot assembly, with the sensor rod
and hot flag, had been bent out of position during manufacturing. If the
heater had been off long enough for the gas in the burner lines to
dissipate, then when the main gas valve re-opened it created a gust of air
that turned off the pilot sensor before the burnable mixture could get to
the pilot and ignite. It seems those "rectifying" sensors are a _lot_
faster to turn off than a thermopile would be! Moving the pilot assembly to
its proper position let the sensor stay on long enough to ignite the main
burner.

Loren

On 11 Jan 2004 14:18:08 -0800, the renowned jim rozen
wrote:

In article , Gunner says...

...the flame rod is a device that puts 100 or so volts on the flame
rod, which is exposed to the flame, and uses flame rectification to
convert this to dc and then to ground. It senses the ground path

Thanks, I've learned something today. I've never
seen those, all the flame decectors I've been aware
of are either thermocouples or CdS photocells.

Some of the big industrial ones use a special electronic gas tube that
is sensitive only to ultraviolet light. They are sunlight-blind even
without a filter but respond to the UV given off by a flame.

Also the SiC ignitor modules in our oven - which always
seem to burn out at the *worst* time!

Same thing with the hot-surface ignitor in our furnace. I should pick
up a spare.. thanks for reminding me.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Gunner wrote in message . ..
Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

I ran into a simlar problem on our furnace. A friend suggested that I
check the "flame sensor". In my unit it was a stainless steel rod that
stuck into the flame. I removed it, it is on a little bracket, and
cleaned it with denatured alcohol and when I reinstalled it the
furnace worked fine. My friend said that
after years of being stuck into a flame, the sensors get coated with a
fine
film of ash that insulates it. All I know is that a good cleaning
solved my problems.
Terry

On Sun, 11 Jan 2004 16:10:20 -0500, "Blake Loyd"
wrote:



"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

What's the gas pressure to the unit? I installed a new furnace a few years
ago that wouldn't fire the main burner. Turned out the pressure was
slightly
higher than the valve could take. Old furnace worked fine for many years
at
the same pressure....Paul


Your question brings up other issues.
I'd assumed it was a piece of equipment that was already in use.
Is the equipment new? Had it been working and stopped? Had repairs
been done to it recently and if so what?
Your point about the gas pressure is a good one, especially if the
equipment is new or the gas valve has been changed.

Loyd

Existing installation, just getting flakier and flakier. I dont have
any way to test the manifold pressure (gas), or the blower pressure,
though the blower does have a shunt to increase or decrease blower
pressure. Its never been moved as far as I can see.

Gunner

"Gun Control, the theory that a 110lb grandmother should
fist fight a 250lb 19yr old criminal"

"Gunner" wrote in message
...
Existing installation, just getting flakier and flakier. I dont have
any way to test the manifold pressure (gas), or the blower pressure,
though the blower does have a shunt to increase or decrease blower
pressure. Its never been moved as far as I can see.

Ok. You could take some clear plastic tubing and build a manometer. Or
if push came to shove, put in a Schrader valve and use a tire gauge to get a
rough reading. But the gas pressure probably isn't the problem since it is
a preexisting system, unless the pressure regulator for the gas has gone
bad.
Another things to consider, since we can't see the setup, is the
environment. Is it in a humid or dusty area? Humidity can cause spade
connections to corrode, and if it is bad it can cause the burner to rust
inside and the rust can block the gas flow.. Dust can get into burners and
block the gas flow. It is a heater system to remove water from oil. Is the
water vented outside or inside where the unit is? Is there any corrosive
chemical used in the area? If so, connections may be corroding. Take a
good look at the inside of the unit to see if it looks like water has been
condensing in it. If so, the controller may have simply gone bad due to the
water.
Others have mentioned the flame sensor may be dirty. That could easily
be the case especially if the flames have any yellow in them, the flames
should burn blue. Yellow means incomplete combustion and sooting. Check
the inside of the combustion chamber for sooting. Remove the flame sensor
and wipe the sensor with a clean paper towel.. A little discoloration on the
towel is normal but there shouldn't be black soot or at least very little.
If cleaning the sensor solves the problem, inspect the inside of the burner
to insure it is not blocked with foreign matter(dust, insect, rust,etc.),
adjust the air inlet(s) on the burner(s) to eliminate any yellow flame. If
the blower supplies the air for the burner, adjust the blower to eliminate
any yellow flame.
If the system is a very old one consider the gas line for a moment. Does
it have a drip leg. If it has a drip leg at the unit, you might turn off the
gas and remove the drip leg to insure that it isn't full. If for some
reason oil or water has filled the drip leg it could be causing the flame to
burn yellow and soot. But honestly, I've never seen a drip leg get that
full. If it doesn't have a drip leg you might install one to prevent any
oil or moisture from making it to the gas valve and burner. I take it the
lines are iron pipe since you said they were 1". But since the unit has
been there for some time any oil in the pipes that could migrate to the unit
has probably already done so.

Loyd

On Sun, 11 Jan 2004 02:12:43 GMT, Gunner
wrote:

Ive got a problem with a water heater at work. This is a natural gas
unit used to boil water out of oil for reusing the oil

Controller is a Honeywell S89F controller. Everything checks out
normally..sorta

Unit is powered up, gas on.
35 second prepurge cycle starts

At this point, for 4 seconds the ignitor fires up, the gas solenoid is
supposed to open, and then run for a few seconds to allow the flame
sensor to stablizes (DC rectification through the flame) then run. If
no flame, its supposed to recycle another 3 times then lock out if no
burn is detected.

My problem

When the solenoid voltage for the gas valve comes on..it makes and
breaks 3-4 times, or simply comes on then quits within a second. If
the flame actually does fireup, it may trigger the solenoid on and off
click click click for the 3-4 seconds, then shuts down sometimes it
only clicks once. It may or may not go through the following 3
recycles.

Ive checked the ground, cleaned all the grounding connections, double
checked the ignitor via jumper and still I cant figure out whats
causing it to not come on and stay on. Input voltage is constant, the
24vts to the controller is constant, etc etc.

I put a DC milliamp meter in line with the flame sensor rod, but was
unable to get any reading in the second or two that the flame actually
did come on.

Do I have a bad flame sensor or a bad controller? The flame sensor
appears to be in the proper position from the burner face, and the
flame sensor lug does appear to have 110vts on it, measured to ground.

Any ideas? My gut instinct is a flaky controller, but the entire
blower unit was removed and taken to the dealer where it did work
properly, its alleged by the staff.

This is the manual for the unit
http://hbctechlit.honeywell.com/tech...0s/68-0066.pdf

Gunner


Well, you've gotten some good advice so far. Gunner.

I read thru the responses to your posts. Seems as if folks have
covered all the probable things.

So I doubt I can offer much of value.

However, a couple points stick out in my mind and cause me to go
Hmmmm.

You say entire blower unit was removed and sent off for a bench test
and it supposedly worked there, on their test bench.
AND
You say it doesn't work on site.
AND
You describe the sequence of operation of the controller as being
somewhat flakey on site. Sometimes multiple cycling of the solenoid,
sometimes not. Sometimes does the 3 retries, sometimes not.

The above bothers me. Makes me sorta curious.

The thing about those controllers is that internally, they have
digital circuitry. All digital circuits absolutely HATE differences
in ground potential, any differences, between this point and that.
Some are a little more tolerant than others, some less.

In my experience, that particular series of Honeywell controllers is
one of the top haters of any differences in ground potential anywhere
within it's internals, or anything connected to it.

Differences in ground potential which are minute, which would make no
difference in electrical or electronic controls systems, can confuse
and confound that line of Honeywell controllers.

So I wonder to self.

Hmmm. What is different between what you're calling the "blower
assembly", which worked on a test bench. And what you're working with
when you have everything put together on site, and now things aren't
working.

Did that "blower assembly" (I have no clear picture of exactly,
precisely all the components you mean when you say that), as tested on
the test bench include the very same transformer? The same solenoid
valve? The same gas valve? Etc.

Do you see what I'm getting at? What's different that's connected to
that controller now, from what was connected to it when it was bench
tested.

First thing which jumps into my mind is that often when somebody says
"blower assembly" ... that doesn't include the burner itself. May, or
may not. ---- ALL---- grounds that system, anywhere in it, is supposed
to have, MUST be solidly connected to that burner. You don't want
even 2 ohms of difference between this leg of ground and that. Check
the schematic. See all the points to be ground. Make absolutely sure
that when testing from this point in ground to another, that your
meter is as flatlined as possible. Personally, I'd make sure I wasn't
measuring anything over one ohm anywhere. Less if I can make it
happen.

Next, I'd check connection from burner to cabinet. Now, sometimes
folks rely on simple metal to metal contact between the pipes and
other metal parts to establish that electrical connection to ground.
And there is no separate ground wire bolted to burner, then bolted to
the cabinet. This can work fine on a brand new unit.

Can suck, and drive yah nuts trying to figure out the problem on an
older unit. With age, joints and connections corrode. Resistance
increases. Or ground path included a section of pipe, and somebody
took it apart, and upon reassembly used some sealant on threads. And
what used to be a good ground path is now not such a good one.

I'd make sure. I'd add a damned good ground wire from burner to
cabinet if there was not one. If there is, I'd investigate. Conductor
intact? Both connections good, and solid and clean? Etc.

I'd then double check. Power shut down. Do I measure zero ohms, or
damned close to it, from grounded leg of transformer to cabinet? From
gas valve grounded terminal to cabinet? Ground terminal(s) on
controller to cabinet? Ground of ignitor to cabinet? Etc.

That everything looks okay, doesn't hack it. Measure, verify. No
more than 1 ohm, preferrably less. And I'd personally go for less.

After verifying that. My next step would be to verify, beyond any
doubt, that the cabinet is grounded to EARTH ground.

One problem when dealing with digital circuits in particular arises
here. In many installations, particularly older installations,
cabinet ground was made by the electrician with him relying on a
ground path running thru the conduit (if there is some) itself. In
other words, he used the metal pipe as a ground path. This kinda,
sorta works. Most times, most applications, works fine.

At first.

Problem is, the passage of time. All those conduit fittings that used
to be tight, clean, nice metal to metal contact, after the passage of
time often become not so tight, not so clean, etc. And if cabinet
itself was grounded to earth ground via a path thru the conduit
material itself, over the passge of years you might find there is
significant resistance now built up (and thus potential, voltage,
differences) between the cabinet and the actual earth ground of the
building. As measured at the electrical service entry.

Not a good thing. Couple volts aren't gonna hurt or even be
noticeable to regular electrical devices. Some types of digital
devices, and that Honeywell controller is one of em, aren't gonna like
it much.

BTW, do NOT consider a connection to AC common the same as a
connection to ground. Period. I don't care that back at the breaker
panel common may be hooked to the same ground bar as the ground wires.
Do NOT consider a common wire as ground. Ground is ground. Common in
normal operation carries current. Yah don't want the ground for that
controller hooked to anything carrying current. Will confuse the
devil out of it.

The above ground related things, I'd be inclined to check, and double
check first.

Then I'd check whatever else is hooked to that controller one way or
another, that did not accompany it to the shop for bench test. What
else, that wasn't attached to it during bench test, might be shorting
to ground, drawing too much current, etc.

Sometimes a transformer will seem fine. Measure output voltage, she
looks good. Hook her up to something that's drawing too much
amperage, i.e. a relay or solenoid which does a big spike draw upon
energizing, voltage droops. Sometimes very quickly then comes back to
normal because relay coil dropped out and field collapsed. And what
you hear is chatter. Often yah can't see that rapid fluctuation on
many meters. But yah can usually hear it. Problem might be relay or
solenoid coil is drawing more than it used to, particularly on
energizing and making something move (inrush current), or windings are
starting to fail and after a moment get too hot. Or sometimes it's
the transformer. Age. Might say 40 watts on the label, but she can't
handle half that any more. And particularly on inrush current draw,
she starts putting out erratic, drooping voltage. Digital circuitry
does not like this sort of thing.

Just some thoughts.

Best of luck.

Bob