Home Page link

Armstrong EG6A125DC15-13 Roll Out Switch

Home| Search | About
Login Password
Register Now! Lost Password?

HVAC Discussions - Heating, ventilation and air conditioning. 

Page 3 of 3       << first < 1 2 3 Bookmark this page:  YahooMyWeb Yahoo!  Google Google  Windows Live Favorites Windows Live  del.icio.us del.icio.us  digg digg  Add to Netscape Netscape
Subject Author Date
Armstrong EG6A125DC15-13 Roll Out Switch Bob Shuman 02-14-2008
If you were  Registered and logged in, you could reply and use other advanced thread options
Posted by Zyp on February 19, 2008, 11:35 am
Bob Shuman wrote:
> To clarify, the switch I am having trouble with is at the top of the
> unit nearest to the exhaust flue. It is called a "roll out" switch
> in the schematic drawing, so I called it the same. It is identical
> to the "roll out" switch at the front and slightly above the burner
> elements. That switch seems to be operating fine since it is not
> tripping.
> Also, someone suggested the furnace may be short cycling, but this is
> not the case either. The thermostat calls for heat, the pilot gets
> gas, the electronic ignition kicks in and the pilot lights, then the
> thermocouple senses the flame and turns on gas to the burners which
> ignite. They burn for about 20-30 seconds and the blower fan kicks
> in. The gas burners and blower run till temperature is reached and
> the thermostat shuts off, the gas valve closes and the burners shut
> down. The blower fan runs for a few minutes and then shuts off when
> the low temp limit is reached.
> I just do not understand why the sheet metal at the top near the
> exhaust flue gets hot enough to shut down the unit when the manual
> shut off valve is fully opened. Hope this clarifies the situation.
>
> Bob
>
>> I'm sorry, I thought the tread was about the flame roll out not the
>> blocked flue switch. Can you clarify????

That's a lot clearer Bob;

The control adjacent to the flu stack is a "draft safeguard switch." It's
purpose in life is to prevent back drafts. You have a flue problem. Go see
if the flu stack is high enough [i.e. 24" above any projection within 10
feet of the stack.] If you have prevailing winds, it could be "back
drafting" long enough to trip the control. You might have to many turns in
the flu stack as well. It must not have more than one 90 degree turn
meaning 45 degree turns are ok. It must have a buoyant head, meaning the
stack leaving the appliance must have at least 12" of vertical before taking
turns [unless the appliance is lying in a horizontal position.] See the
Mfg.'s instructions and for advice.

If anything, call a certified NATE technician. He / she will see the
problem fairly quick.

Zyp

--
Zyp



PexSupply Full Banner
Posted by Bob Shuman on February 20, 2008, 9:24 am
Zyp & ftwhd,

Thanks for your helpful comments. I'll take it from here.

Bob



Posted by Bubba on February 14, 2008, 9:19 pm
On Thu, 14 Feb 2008 09:52:20 -0600, "Bob Shuman"

>Sorry in advance for the length of this post, but I wanted to try to be as
>specific as possible on this problem.
>
>I have two 16+ year old Armstrong natural gas furnaces (model number in
>subject line above) for my residence. Both identical spark ignition,
>125,000 BTU 5-burner units.
>
>I had a soot build up problem with the lower level unit (the one that is
>used most frequently) that caused the flame on the left-most burner to
>slightly roll out from the heat exchanger chamber, so I called a reputable
>local service company to come out and clean both of the units.
>
>They removed the flue and front panel and then thoroughly cleaned the sooted
>up heat exchanger and flue vent. (They found the heat exchange cavity by
>the leftmost burner completely blocked with soot). They also removed and
>cleaned all the burners too and then re-assembled everything. In this
>process, they also discovered that the air mixture controls for the 5
>burners were shut down completely and opened them up (all the way to max
>settings) to let the burners "breathe" properly. The flame tip color turned
>a much deeper blue and the dark blue "inner" flame mantles appeared to go
>down to about 3/4" long. The good news here was that this stopped the
>orange tipped flame from rolling out of the combustion chamber and resulted
>in a noticeably hotter flame. (I've also been monitoring CO in the area
>around the furnaces and it has gone from 20+ PPM when the furnace was
>running to 0 PPM now.)
>
>Unfortunately, changing the air mixture seems to have introduced a new
>problem. Now during extended runs of this furnace (for example when coming
>up to temperature in the AM after a setback period the previous night), the
>flue roll out switch trips shutting down the system. When this happens it
>requires a manual reset of the roll out switch button. If the furnace is
>simply "cycling" to maintain temperature, then it does not seem to trip and
>everything is fine. The drafting on the furnace seems to be good so I
>suspected that it was just burning too hot for the switch.
>
>Thinking this was possibly a weak/old/failing roll out switch, I swapped the
>switch with the one in my upstairs furnace, but this did not fix the problem
>and it still tripped just the same (and the upstairs unit which now has the
>switch from the downstairs unit did not trip). At this point, I have tried
>backing off the air mixture to about 50% from being wide open on all 5
>burners, but this too seems to have had no affect.
>
>The only thing that I've found that does seem to prevent this switch from
>tripping is to manually feather the gas shut off valve to the point where I
>can observe a noticeable reduction in the flame height on the 5 burners.
>
>I'd appreciate thoughts on what is happening here. I do not believe it is
>an issue with a blocked flue since both furnaces were thoroughly cleaned and
>share the same flue stack/chimney and the upstairs unit does not have this
>same problem. I suspect it may be that the air/fuel mixture is still not
>correct or possibly that the gas pressure from the gas valve to the burner
>orifices on the lower level furnace may be set too high. (I am not sure how
>these are set.) My service company is stumped and after being charged for
>two trips, I am not anxious to have them come back till I understand what is
>happening here.
>
>Thoughts and ideas on what I can look at or try are very much appreciated.
>I know these units are only about 65% efficient and getting old, but
>replacement at this time is not an option since they are otherwise still
>running well!
>
> Bob
>
>
WOW! Simply amazing! I hate to be so blunt but everyone here knows
thats the way I do it so try not to take this too personal.
Unfortunately, I cant quite figure out who is dumber.
Is it the service company that came out and cleaned out all that soot?
OR
Is it the homeowner that has to keep resetting a MANUAL RESET ROLL-OUT
switch?
When you find soot you MUST find out WHY it was produced. It seems
that "someone" didnt. Too bad.
When "someone" has to reset a "manual reset roll-out switch" one must
determine, WHY is this having to be reset?
Both clues (the soot and the manual resetting) can be VERY dangerous
conditions and even life endangering.
You most likely have a cracked heat exchanger.
Time to break open the piggy bank and get some properly sized high
efficiency furnaces.
Bubba

Posted by jamesgangnc on February 15, 2008, 11:34 am
On Feb 14, 10:52=A0am, "Bob Shuman" <reshu...@removethis.alcatel-
lucent.com> wrote:
> Sorry in advance for the length of this post, but I wanted to try to be as=

> specific as possible on this problem.
>
> I have two 16+ year old Armstrong natural gas furnaces (model number in
> subject line above) for my residence. =A0Both identical spark ignition,
> 125,000 BTU 5-burner units.
>
> I had a soot build up problem with the lower level unit (the one that is
> used most frequently) that caused the flame on the left-most burner to
> slightly roll out from the heat exchanger chamber, so I called a reputable=

> local service company to come out and clean both of the units.
>
> They removed the flue and front panel and then thoroughly cleaned the soot=
ed
> up heat exchanger and flue vent. =A0(They found the heat exchange cavity b=
y
> the leftmost burner completely blocked with soot). =A0They also removed an=
d
> cleaned all the burners too and then re-assembled everything. =A0In this
> process, they also discovered that the air mixture controls for the 5
> burners were shut down completely and opened them up (all the way to max
> settings) to let the burners "breathe" properly. =A0The flame tip color tu=
rned
> a much deeper blue and the dark blue "inner" flame mantles appeared to go
> down to about 3/4" long. =A0The good news here was that this stopped the
> orange tipped flame from rolling out of the combustion chamber and resulte=
d
> in a noticeably hotter flame. =A0(I've also been monitoring CO in the area=

> around the furnaces and it has gone from 20+ PPM when the furnace was
> running to 0 PPM now.)
>
> Unfortunately, changing the air mixture seems to have introduced a new
> problem. =A0Now during extended runs of this furnace (for example when com=
ing
> up to temperature in the AM after a setback period the previous night), th=
e
> flue roll out switch trips shutting down the system. =A0When this happens =
it
> requires a manual reset of the roll out switch button. =A0If the furnace i=
s
> simply "cycling" to maintain temperature, then it does not seem to trip an=
d
> everything is fine. =A0 The drafting on the furnace seems to be good so I
> suspected that it was just burning too hot for the switch.
>
> Thinking this was possibly a weak/old/failing roll out switch, I swapped t=
he
> switch with the one in my upstairs furnace, but this did not fix the probl=
em
> and it still tripped just the same (and the upstairs unit which now has th=
e
> switch from the downstairs unit did not trip). =A0At this point, I have tr=
ied
> backing off the air mixture to about 50% from being wide open on all 5
> burners, but this too seems to have had no affect.
>
> The only thing that I've found that does seem to prevent this switch from
> tripping is to manually feather the gas shut off valve to the point where =
I
> can observe a noticeable reduction in the flame height on the 5 burners.
>
> I'd appreciate thoughts on what is happening here. =A0I do not believe it =
is
> an issue with a blocked flue since both furnaces were thoroughly cleaned a=
nd
> share the same flue stack/chimney and the upstairs unit does not have this=

> same problem. =A0I suspect it may be that the air/fuel mixture is still no=
t
> correct or possibly that the gas pressure from the gas valve to the burner=

> orifices on the lower level furnace may be set too high. =A0(I am not sure=
how
> these are set.) =A0My service company is stumped and after being charged f=
or
> two trips, I am not anxious to have them come back till I understand what =
is
> happening here.
>
> Thoughts and ideas on what I can look at or try are very much appreciated.=

> I know these units are only about 65% efficient and getting old, but
> replacement at this time is not an option since they are otherwise still
> running well!
>
> =A0 Bob

You got a draft issue. Either the flue is still stopped up somewhere
or there is not enough fresh air available to supply the unit. Other
possibility is that your flue never was adequate and the original
installed dicked with your mixture in an effort to mask the flue
problem.

Page 3 of 3       << first < 1 2 3
Similar ThreadsPosted
Re: Armstrong EG6A125DC15-13 Roll Out Switch November 9, 2008, 11:10 am
Heater Hustlers from Canton again: HEAT SURGE Roll-n-Glow Fireplace December 12, 2007, 11:11 am
Heater Hustlers from Canton again: HEAT SURGE Roll-n-Glow Fireplace December 12, 2007, 11:09 am
Armstrong pump August 12, 2006, 2:41 pm
Baldor/Armstrong#3 October 6, 2006, 1:03 pm
armstrong/baldor update October 3, 2006, 11:19 am
Armstrong gas furnace won't kick off November 20, 2006, 3:49 pm
Fan/ Limit switch November 1, 2006, 10:39 am
Pressure switch March 1, 2008, 9:01 pm
Loss of Charge Switch July 26, 2006, 10:28 am

Contact Us | Privacy Policy

XML SitemapXML Sitemap