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Honeywell MagicStat thermostat -> questions about jumper settings on the back

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HVAC Guy

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Dec 29, 2011, 9:52:33 AM12/29/11
to
I've got a Honeywell MagicStat thermostat that has 2 jumpers marked as
"A" and "B" that are opened or closed by a screw head that you tighten
(to close the jumper) or turn out (to open the jumper).

There are 2 other jumpers (C and D) - C is to set Celcius or
Farenheight, but I don't know what "D" is for (there is no screw for
that one - so it's open). I can find no reference anywhere what D could
be for.

I'm not quite sure what exact model of MagicStat I have - there is
absolutely no number or name stamped or printed on this thing. Not even
the word "MagicStat". I've seen models like 28, 1000, 2800 and 3200
from web searches. I believe this one was purchased between 1996 and
1999.

This is the most similar picture I could find of the front panel:

http://img.ehowcdn.co.uk/article-page-main/ehow/images/a08/7r/3r/installation-instructions-honeywell-t8000c-1010-800x800.jpg

And this is the best picture for the entire unit:

http://www.honeywellcentral.com/media/product_images/CT3200A1001-U_lg.jpg

The thermostat is controlling a 20+ year-old GE "Whisper-heat" natural
gas furnace. This is NOT a high-efficiency (or condensing) furnace, but
it does have an electronic control module, combustion damper gate and
electronic ignition.

The furnace is cycling too often to suit me, and so I'd like to know if
the thermostat can be modified to solve that.

The written documentation for the A and B jumpers are as follows:

Warm Air Furnace: Set at the Hot Water setting (A-out, B-in)
Electric furnace: Leave at the Warm Air Furnace setting (A-in, B-in)

(the way the second line reads is confusing)

It also says:

For high efficiency (>90% AFUE): A-out, B-in

On the back of the unit these instructions are stamped into the plastic
case:

Warm Air Furnace: A-in, B-in, Fuel Switch F
Hot Water Boiler: A-out, B-in, Fuel Switch F
Electric Furnace: A-in, B-out, Fuel Switch E

On my thermostat, the current settings are:

Warm Air Furnace: A-in, B-in, Fuel Switch F

I believe that the only thing the Fuel Switch does is turn on the fan
when heat is called for (in the E setting) otherwise the fan is turned
on by the furnace (in the F setting).

So if anyone knows, I'd like some clarification as to how exactly the A
and B settings work or how they modify the operation of the furnace.

It would be nice if there was a SPAN or hysteresis setting so I could
force a 1 or 2 degree swing so the cycles last longer, but I see no such
setting. I'm wondering if the A and B settings can accomplish this?

And -> anyone know what the D jumper does?

ilbe...@gmail.com

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Dec 29, 2011, 11:56:55 AM12/29/11
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On Dec 29, 8:52 am, HVAC Guy <H...@Guy.com> wrote:
> I've got a Honeywell MagicStat thermostat that has 2 jumpers marked as
> "A" and "B" that are opened or closed by a screw head that you tighten
> (to close the jumper) or turn out (to open the jumper).
>
> There are 2 other jumpers (C and D) - C is to set Celcius or
> Farenheight, but I don't know what "D" is for (there is no screw for
> that one - so it's open).  I can find no reference anywhere what D could
> be for.
>
> I'm not quite sure what exact model of MagicStat I have - there is
> absolutely no number or name stamped or printed on this thing.  Not even
> the word "MagicStat".  I've seen models like 28, 1000, 2800 and 3200
> from web searches.  I believe this one was purchased between 1996 and
> 1999.
>
> This is the most similar picture I could find of the front panel:
>
> http://img.ehowcdn.co.uk/article-page-main/ehow/images/a08/7r/3r/inst...
>
> And this is the best picture for the entire unit:
>
> http://www.honeywellcentral.com/media/product_images/CT3200A1001-U_lg...
I remember that Thermostat . The A and B screws act as a heat
anticipator does ; the more you back out the A screw with the B
screw turned all the way in....the greater the differential will be
and the greater the room temperature swing will be . It is all done
by trial and error using the screws , so, you have to set the screws
then cycle the system thru a couple times to see what kind of room
temperature drop youre getting before the next heating cycle starts.
Since the furnace has electronic ignition, youll want to set it up as
if it were a high efficiency gas furnace which ordinarily would
correspond to a .8 amp anticipator setting ; thats what you have to
shoot for by trial and error by adjusting the Magic Stat screws.
(They dont call it an 'inexpensive' thermostat for no reason !) .
If , after youve done that and you still get a rapid cycling
response...then you could install a simply spst start relay at the
furnace which would effectively reduce the heat anticipator (amp)
demand of the Magic Stat and possibly bring you within the operating
range of the A / B screws for more consise adjusting . ... the Magic
Stat would operate the added relays coil directly , with the relay
contacts making and breaking R to W at the furnace control board
strip . Good luck. ALso, theres a Honneywell Thermostat Tech 800
number for Contractors ; if you need it i can try and find it for
you.

Steve

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Dec 29, 2011, 2:16:10 PM12/29/11
to

"HVAC Guy" <HV...@Guy.com> wrote in message news:4EFC7EB1...@Guy.com...
Sounds like your trying to use the thermostat to mask the primary
problems.... and that would be having a furnace that is a whole lot bigger
than you need, and not enough insulation.
20 years is a normal *high* life span for a gas furnace. It would be time to
look into replacing the furnace before it becomes a problem and craps out
when its really cold.

The contractor that installs the new furnace should do a complete
room-by-room Manual J heat load/loss analysis to correctly size the new
furnace for your home. You might be surprised at the results.


cjt

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Dec 29, 2011, 3:39:04 PM12/29/11
to
I think you're assuming a LOT (like where the O.P. resides).

Steve

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Dec 29, 2011, 6:07:55 PM12/29/11
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"cjt" <chel...@prodigy.net> wrote in message
news:4EFCCF...@prodigy.net...
He still has a 20+ year old furnace.... doesn't matter where he lives... and
short cycling still indicates a grossly oversized furnace no matter where
you live.

Dave M.

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Dec 29, 2011, 7:10:12 PM12/29/11
to
I've got the Honeywell CT3200, which matches your pictures but not your
description. My unit has 3 dip switches and a larger fuel switch.
The manual offers no suggestions about altering the duty cycle. The
furnace is expected to cycle about 5 times per hour and is meant to hold
within 1 deg F of the setpoint.

Dave M.


HVAC Guy

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Dec 29, 2011, 9:37:18 PM12/29/11
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Steve wrote:

> He still has a 20+ year old furnace.... doesn't matter where he lives.
> .. and short cycling still indicates a grossly oversized furnace no
> matter where you live.

Why are you such a trollish Klown?

Or are you naturally stupid when it comes to furnaces and thermostats?

Any boob knows that it's the thermostat that controls the cycling of the
furnace.

You can make ANY furnace short-cycle given a tight temperature span.

HVAC Guy

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Dec 29, 2011, 9:44:27 PM12/29/11
to
"IlBe...@gmail.com" wrote:

> I remember that Thermostat . The A and B screws act as a heat
> anticipator does ; the more you back out the A screw with the B
> screw turned all the way in....the greater the differential will be
> and the greater the room temperature swing will be.

Your explanation indicates that the amount of turns of the screw is
somehow sensed by the thermostat's circuitry.

This assumption is incorrect.

On this thermostat, the screw is not functioning as the core of an
inductor or coil (as per your explanation). The only function the screw
has is to bridge the wire contacts on the upper surface of a machined
plastic block. The wires connect to the PC board.

If variable operating was desired, then Honeywell would have used a
potentiometer instead of a significantly more complicated reactance
circuit.

All the printed manuals for these thermostats indicate that the screw
has basically only 2 settings: Fully turned in (tightened down) or
unscrewed (turned out) by one turn. The one turn is sufficient to raise
the underside of the screw head enough so that it is not contacting
(bridging) the wires.

HVAC Guy

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Dec 29, 2011, 10:19:46 PM12/29/11
to
"Dave M." wrote:

> I've got the Honeywell CT3200, which matches your pictures but not
> your description. My unit has 3 dip switches and a larger fuel
> switch.

I obtained the documentation for a MagicStat CT3300 and it shows a
diagram of the back of the unit that is identical to what I have. I
copied that diagram and it can be seen here:

www.fileden.com/files/2008/7/19/2010382/Magicstat.gif

The PDF file itself can be downloaded from here:

www.fileden.com/files/2008/7/19/2010382/MagicStatCT3300.PDF

> The manual offers no suggestions about altering the duty cycle.

That appears to be the case from what I read as well.

> The furnace is expected to cycle about 5 times per hour and
> is meant to hold within 1 deg F of the setpoint.

That's a pretty tight temperature range and to be able to hold it within
1 degree F and keep to only 5 cycles per hour really depends on a lot of
factors (how the premesis is constructed, how drafty it is, how cold /
windy is it outside, how many BTU's the furnace puts out, etc).

This thermostat basically has 4 binary-selectable settings:

A-in / B-in Conventional warm-air (nat-gas?) furnace
A-in / B-out Electric furnace (or electric base-board?)
A-out / B-in Hot water boiler (radiant heat?)
A-out / B-out not defined (hmm...)

Just guessing here, but why would a thermostat need to know between
which of the above 3 systems is it controlling?

The speed of response of the system? Nat-gas forced-air can respond
faster than a boiler, for example. To anticpate the call for heat
(reduce the control span?)

The thermostat doesn't want the ambient temp to drop too far below the
setpoint, and it doesn't want to over-shoot the setpoint. It's not
clear which of the above options would give me a wider span (and hence
fewer cycles per unit time). I guess I'll just have to experiment - or
buy a new thermostat with a user-settable span or hysteresis setting.

Dave M.

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Dec 30, 2011, 8:19:35 AM12/30/11
to
Guy,

I agree with your conjecture that the screws (in your case) or DIP
switches (in mine) change the anticipator circuit and thus adjust the
cycling.
I suspect that experimenting with them will be harmless but unrewarding.
The settings recommended in the manual are those that will work best.
Let me know if you find better settings.

Dave M.


Steve

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Dec 30, 2011, 9:50:19 AM12/30/11
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"HVAC Guy" <HV...@Guy.com> wrote in message news:4EFD23DE...@Guy.com...
Sure... go ahead on... you know what your doing, so you don't need to worry
with posting questions about ancient POS big box stats.... when you can get
a good one for $50 or so.

Just cause your "HVAC Guy" doesn't mean squat.... you should have a decent
stat on your truck that you can use instead of screwing with a POS.



ilbe...@gmail.com

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Dec 30, 2011, 4:41:49 PM12/30/11
to
On Dec 29, 8:44 pm, HVAC Guy <H...@Guy.com> wrote:
Whenever i adjusted the 'A' screw in or out partially...it DID make a
difference on the cycle time (differential) . I wouldnt give
Honneywell too many accolaides as far as engineering goes because this
thermostat of theirs is a poor example of quality..certainly one
Engineers wet dream to flood the market with a most inexpensive
thermostat without much consideration to accuracy. A proper
electronic thermostat that is designed well, is one where the Person
can make a definitive selection between 1,2,or 3 degrees F.
differential for heating AND for cooling....and not a psuedo-
thermostat like a Honneywell Magic Stat. Sadly, these are things the
typical homeowner isnt up to par on.

ilbe...@gmail.com

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Dec 30, 2011, 4:46:05 PM12/30/11
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On Dec 30, 8:50 am, "Steve" <jstev...@comcast.net> wrote:
> "HVAC Guy" <H...@Guy.com> wrote in messagenews:4EFD23DE...@Guy.com...
The Honneywell Magic Stat was nothing but a wet dream without any
thought to accurate differential control . It shouldnt have even been
on the market and no doubt, it didnt do much for Honneywells
reputation which youd think theyd be quite interested in
maintaining.

Steve

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Dec 30, 2011, 6:48:43 PM12/30/11
to

"IlBe...@gmail.com" <ilbe...@gmail.com> wrote in message
news:807abe22-ad3c-4725...@m10g2000vbc.googlegroups.com...
------------------------------------

the magic was how it lined honeywells pockets...it was in the same class as
hunter stats





ilbe...@gmail.com

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Dec 31, 2011, 4:37:08 PM12/31/11
to
On Dec 30, 5:48 pm, "Steve" <jstev...@comcast.net> wrote:
> "IlBeBa...@gmail.com" <ilbeba...@gmail.com> wrote in message
Totally agree . The Hunter wouldnt properly control anything beyond
a .4 amp device in the heating mode.

HVAC Guy

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Jan 7, 2012, 10:55:12 PM1/7/12
to
"IlBe...@gmail.com" wrote:

> Whenever i adjusted the 'A' screw in or out partially...it DID
> make a difference on the cycle time (differential) .

My gut feeling, based on turning out the A screw, is that the furnace
cycle time has been lengthened to a more satisfactory condition, with no
discernable change in overall ambient air temperature.

A-out / B-in Hot water boiler (radiant heat?)

So this is, in effect, telling the thermostat that instead of
controlling a conventional mid-efficiency forced-air natural gas
furnace, that it's controlling a hot water boiler.

This seems to have the effect of not turning on the furnace as often.

Grumpy

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Jan 15, 2012, 10:06:20 AM1/15/12
to
Sorry guys but some how you guys getting on my nerves
you being discussing this Fxxxxxx Magic Thermostat for past month
and I don't see positive explain what type heat does it has
is it hot water or is it hot air electrical/gas or does this thermostat controls home/buld. temp.
Or you are trying to use VW motor to drive Cad.

"HVAC Guy" <HV...@Guy.com> wrote in message news:4F0913A0...@Guy.com...

Steve

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Jan 15, 2012, 12:53:33 PM1/15/12
to
I still haven't figured out why nobody has posted the link for the
instructions for this antique big box store POS stat.

Either the OP is an idiot (this is a given), and/or he's just too freakin
lazy to actually look for it, and/or hes nothing but another troll.
A simple yahoo search gets over 19,000 hits. How hard is this??

http://customer.honeywell.com/TechLit/pdf/69-0000s/69-0653.pdf

You can also go to the Honeywell site and get it from there....



"Grumpy" <t.s...@verizon.net> wrote in message
news:WJqdnXWIpdfwdo_S...@giganews.com...

HVAC Guy

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Jan 15, 2012, 1:26:55 PM1/15/12
to
Steve wrote:

> I still haven't figured out why nobody has posted the link for the
> instructions for this antique big box store POS stat.
>
> Either the OP is an idiot (this is a given), and/or he's just too
> freakin lazy to actually look for it, and/or hes nothing but another
> troll.

That's right.

Show what a usenet dumb-ass you are by calling everyone a troll.

> A simple yahoo search gets over 19,000 hits. How hard is this??
>
> http://customer.honeywell.com/TechLit/pdf/69-0000s/69-0653.pdf
>
> You can also go to the Honeywell site and get it from there....

Why the hell are you such a fucking ass hole Steve?

I've got the fucking pdf instructions for the stat. If you had half a
brain, you would have seen that based on my previous posts in this
thread.

If you weren't such an ass-wipe, you'd already know that the stat was
configured properly for the type of furnace it was controlling. But
even though it was properly configured, it was cycling too often to suit
my liking.

That's fucking why I started the thread in the first place. To see if
any of you dorks know how this stat reacts when you change it's
settings. You fools obviously didn't know.

So the stat now thinks it's controlling a hot water boiler, and it's not
cycling as often as it was, and I'm satisfied with the end result. The
temperature of the space being heated is comfortable, with no real
detectible hot/cold swings because the stat's duty cycle is longer.

As for you, Grumpy, I don't know what your god damn problem is.

If you bothered to read the entire fucking thread, you might have a clue
as to how this is going down.

> Or you are trying to use VW motor to drive Cad.

What a maroon.

Hugh Jass

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Jan 15, 2012, 1:52:50 PM1/15/12
to
On 1/15/2012 1:26 PM, HVAC Guy wrote:
> Steve wrote:
>> A simple yahoo search gets over 19,000 hits. How hard is this??
>>
>> http://customer.honeywell.com/TechLit/pdf/69-0000s/69-0653.pdf
>>
>> You can also go to the Honeywell site and get it from there....
>
> Why the hell are you such a fucking ass hole Steve?
>

FWIW, I googled "why is steve an asshole?".

I got 207,000,000 hits

take your pick ;-)
Message has been deleted

grumpy

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Jan 15, 2012, 8:12:36 PM1/15/12
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"ftwhd" <ft...@fuckoff.com> wrote in message
news:asq6h7hhrb6lnug9k...@4ax.com...
> On Sun, 15 Jan 2012 13:26:55 -0500, HVAC Guy <HV...@Guy.com> wrote:
>
>>Steve wrote:
>>
>>> I still haven't figured out why nobody has posted the link for the
>>> instructions for this antique big box store POS stat.
>>>
>>> Either the OP is an idiot (this is a given), and/or he's just too
>>> freakin lazy to actually look for it, and/or hes nothing but another
>>> troll.
>>
>>That's right.
>>
>>Show what a usenet dumb-ass you are by calling everyone a troll.
>>
>>> A simple yahoo search gets over 19,000 hits. How hard is this??
>>>
>>> http://customer.honeywell.com/TechLit/pdf/69-0000s/69-0653.pdf
>>>
>>> You can also go to the Honeywell site and get it from there....
>>
>>Why the hell are you such a fucking ass hole Steve?
>>
> Paul left so some one has to take spot.
>
> The King is dead but not forgotten.

COME TO THINK OF IT WHAT HAPPEN TO PAUL???




HVAC

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Jan 16, 2012, 2:15:35 PM1/16/12
to
On 1/15/2012 1:26 PM, HVAC Guy wrote:
> Steve wrote:
>
>> I still haven't figured out why nobody has posted the link for the
>> instructions for this antique big box store POS stat.
>>
>> Either the OP is an idiot (this is a given), and/or he's just too
>> freakin lazy to actually look for it, and/or hes nothing but another
>> troll.
>
> That's right.
>
> Show what a usenet dumb-ass you are by calling everyone a troll.


He's not calling everyone a troll. He's calling YOU an idiot.


He's right.










--
"OK you cunts, let's see what you can do now" -Hit Girl
http://www.youtube.com/watch?v=CjO7kBqTFqo

grumpy

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Jan 16, 2012, 4:46:23 PM1/16/12
to

"HVAC" <mr....@gmail.com> wrote in message
news:jf1t05$mjb$1...@hvac.motzarella.org...
> On 1/15/2012 1:26 PM, HVAC Guy wrote:
>> Steve wrote:
>>
>>> I still haven't figured out why nobody has posted the link for the
>>> instructions for this antique big box store POS stat.
>>>
>>> Either the OP is an idiot (this is a given), and/or he's just too
>>> freakin lazy to actually look for it, and/or hes nothing but another
>>> troll.
>>
>> That's right.
>>
>> Show what a usenet dumb-ass you are by calling everyone a troll.
>
>
> He's not calling everyone a troll. He's calling YOU an idiot.
>


Person like you with such intelligence kiss my Ares does that make you happy


>
> He's right.

PaxPerPoten

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Jan 16, 2012, 7:45:50 PM1/16/12
to
He resigned due to out of good flaming material.
>
>
>
>

Daniel who wants to know

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Jan 16, 2012, 8:35:31 PM1/16/12
to

"Steve" <jste...@comcast.net> wrote in message
news:jev3r0$tp7$1...@dont-email.me...
>I still haven't figured out why nobody has posted the link for the
>instructions for this antique big box store POS stat.
>
> Either the OP is an idiot (this is a given), and/or he's just too freakin
> lazy to actually look for it, and/or hes nothing but another troll.
> A simple yahoo search gets over 19,000 hits. How hard is this??
>
> http://customer.honeywell.com/TechLit/pdf/69-0000s/69-0653.pdf
>
> You can also go to the Honeywell site and get it from there....
>
>

Because not every Honeywell manual is perfect, especially for a cheap HwHwST

The manual for mine, a Honeywell RTH221B1000 that I got 3 of for $5 each
from the Orscheln Farm and Home bargain bin makes no mention of cycles per
hour. If you Google the model RTH221B, you get this manual:

http://www.honeywellcentral.com/ssi/pdf/honeywell/RTH221-Owners-Manual.pdf

However if you Google RTH221B cycles per hour you get this manual:

http://customer.honeywell.com/techlit/pdf/PackedLit/69-2060EFS.pdf

Or Google RTH221B1000 cycles per hour and get this manual:

http://customer.honeywell.com/techlit/pdf/PackedLit/69-2448ES.pdf

The latter 2 manuals both explain how to press both temp arrows together for
3 seconds to enter the hidden settings menu.

If you want a real Honeywell manual you have to step up out of the HwHwST
class and into the professional class, Google Honeywell t8600d t8601d and
get:

http://www.thermostatshop.com/manuals/T8602D%20users%20manual.pdf

Now That's what I call a manual.

HwHwST=Honeywell hardware store thermostat.


HVAC Guy

unread,
Jan 16, 2012, 9:06:20 PM1/16/12
to
Daniel who wants to know wrote:

> The manual for mine, a Honeywell RTH221B1000 that I got 3 of for
> $5 each from the Orscheln Farm and Home bargain bin makes no
> mention of cycles per hour.

Of course not.

Because the number of cycles per hour will depend on

- the temperature span or hysteresis around the desired set point
- the heat loss of the space being controlled
- the BTU capacity of the furnace

If the stat has a setting for cycles per hour, then you're going to have
a variable hysteresis, and the stat is going to take some time to learn
what that's going to be for a given set of conditions.

To make it more complicated, the heat loss of the space is going to be
affected by ambient outside weather (wind and temperature) and how well
the space is insulated. As that changes, the thermostat will have to
re-learn how to control the furnace to keep the desired set-point while
maintaining the desired cycles per hour.

It's far simpler to set the hysteresis (2 or 3 degrees instead of 1
degree) and live with what-ever cycles per hour you end up getting,
rather then aim for a set or fixed cycles-per-hour.

Daniel who wants to know

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Jan 17, 2012, 11:50:09 PM1/17/12
to
"HVAC Guy" <HV...@Guy.com> wrote in message news:4F14D79C...@Guy.com...
>
> Of course not.
>
> Because the number of cycles per hour will depend on
>
> - the temperature span or hysteresis around the desired set point
> - the heat loss of the space being controlled
> - the BTU capacity of the furnace
>
> If the stat has a setting for cycles per hour, then you're going to have
> a variable hysteresis, and the stat is going to take some time to learn
> what that's going to be for a given set of conditions.
>
> To make it more complicated, the heat loss of the space is going to be
> affected by ambient outside weather (wind and temperature) and how well
> the space is insulated. As that changes, the thermostat will have to
> re-learn how to control the furnace to keep the desired set-point while
> maintaining the desired cycles per hour.
>
> It's far simpler to set the hysteresis (2 or 3 degrees instead of 1
> degree) and live with what-ever cycles per hour you end up getting,
> rather then aim for a set or fixed cycles-per-hour.

Did you read any of the PDFs?

Anyway the problem here isn't Honeywell's choice of CPH over hysteresis
degrees, it is how this stat (RTH221) seems to function, when set to 5 CPH
it calls for heat every 12 minutes as expected, but when set to 3 or 1 CPH
in my house it only drops to calling for heat every 13 minutes, and this is
after several hours to adapt. I have a 90+ condensing gas furnace and this
style is only supposed to be cycled about 3 times per hour.

Also interesting with this model is that when set to 62° F as it cycled its
reading would swing from 58° to 65° with each cycle while 3 other
thermometers, a non-connected Lux digital thermostat, a digital meat
thermometer, and an indoor/outdoor thermometer and hygrometer weather
station all placed right beside the RTH221 would all show the swing as being
from 61-63°. When the temp setting on the RTH221 was first set down to 62°
from 68° its reading quickly dropped to 61° and stayed as the 3 others
showed the normal gradual drop. When the others started to show 61° as well
the RTH221 dropped to showing 60° and shortly thereafter called for heat.

It is an odd model for sure.


Steve

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Jan 19, 2012, 5:27:38 PM1/19/12
to

"Daniel who wants to know" <m...@here.edu> wrote in message
news:jf5j25$c0a$1...@dont-email.me...
Yup... big box store junk..... There is a sucker born every minute that will
buy one.


Grumpy

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Jan 20, 2012, 8:45:47 AM1/20/12
to

"Steve" <jste...@comcast.net> wrote in message news:jfa5d3$bh7$1...@dont-email.me...
>
> "Daniel who wants to know" <m...@here.edu> wrote in message news:jf5j25$c0a$1...@dont-email.me...
>> "HVAC Guy" <HV...@Guy.com> wrote in message news:4F14D79C...@Guy.com...
>>>
>>> Of course not.
>>>
>>> Because the number of cycles per hour will depend on
>>>
>>> - the temperature span or hysteresis around the desired set point
>>> - the heat loss of the space being controlled
>>> - the BTU capacity of the furnace
>>>
>>> If the stat has a setting for cycles per hour, then you're going to have
>>> a variable hysteresis, and the stat is going to take some time to learn
>>> what that's going to be for a given set of conditions.
>>>
>>> To make it more complicated, the heat loss of the space is going to be
>>> affected by ambient outside weather (wind and temperature) and how well
>>> the space is insulated. As that changes, the thermostat will have to
>>> re-learn how to control the furnace to keep the desired set-point while
>>> maintaining the desired cycles per hour.
>>>
>>> It's far simpler to set the hysteresis (2 or 3 degrees instead of 1
>>> degree) and live with what-ever cycles per hour you end up getting,
>>> rather then aim for a set or fixed cycles-per-hour.
>>
>> Did you read any of the PDFs?
>>
>> Anyway the problem here isn't Honeywell's choice of CPH over hysteresis degrees, it is how this stat (RTH221) seems
>> to function, when set to 5 CPH it calls for heat every 12 minutes as expected, but when set to 3 or 1 CPH in my house
>> it only drops to calling for heat every 13 minutes, and this is after several hours to adapt. I have a 90+
>> condensing gas furnace and this style is only supposed to be cycled about 3 times per hour.
>>
>> Also interesting with this model is that when set to 62° F as it cycled its reading would swing from 58° to 65°
********************************************************************
Ok enough of this crap apparently your cheepy Tst is much more sensitive

Than the others, to make it more stable you can cover Tst with something

To see how much of effect will have, or/and if you have forced air heating

Make sure that your duct discharge is not blowing on to Tst.

**********************************************************************

HVAC Guy

unread,
Jan 21, 2012, 12:16:20 AM1/21/12
to
Grumpy full-quoted:

> Ok enough of this crap apparently your cheepy Tst

Full quoting dink. Learn how to edit your posts and quote responsibly.

You can't even say "t-stat" or just "stat" ?

You have to shorten it even more?

> to make it more stable you can cover Tst with something

No. I just have to dial out one screw to change the setting.

Read the fucking thread bozo.

Stormin Mormon

unread,
Jan 21, 2012, 7:47:15 AM1/21/12
to
Oh, it's so nice to be back. Just for your reading pleasure, I'll full quote
some more of something or other.
=========================

Subject: COMMON E-MAIL MISTAKES
Date: Saturday, November 08, 2003 7:41 AM

COMMON E-MAIL MISTAKES
Kim Komando


Billions of e-mail messages travel throughout the Internet every day. Here
are six easily avoidable e-mail mistakes.

1. Writing too much
The whole purpose of e-mail is brevity. If you want to write a letter,
then write a letter. A long e-mail just encourages the recipient to skim
it or worse, not read it at all. If what you have to say is really that
complicated, you should probably pick up the telephone.

2. Using sarcasm
Try to look at your e-mail from the recipient's point of view. What may be
acceptable in a face-to-face conversation does not always translate well
in written form. The recipient can't see your body language.

That's why some people use emoticons. They are the Internet equivalent of
body language. For instance, use a smiley face with a colon, hyphen and
close-parentheses mark :-). Or, there's the sad face with the open
parenthesis mark :-(.

Avoid using emoticons in business e-mail. But if you must, don't
overuse them. They interrupt the flow of words. One or two should do the
trick. There is a list of emoticons on my site:
http://www.komando.com/emoticons

3. Expressing anger
Most people use care when selecting words when they speak with another.
E-mail makes it easier to forget yourself. If you're really angry, a
24-hour wait might be in order. Remember: Once you send it, you can't get
it back. And there's no body language to lighten the impact of your words.
If they sound harsh, they will be taken that way.

Capital letters just drive your anger home. Using all capital letters is
considered yelling in the e-mail world. Save it for good news. They may
still irritate your recipients, but they shouldn't alienate them.

4. Forwarding junk
Don't forward virus warnings and urban legends. They are invariably
hoaxes. These things are usually characterized by a vague reference to a
news report months ago. And they always admonish you to forward the
warning to everyone you know.

The anti-virus companies watch closely for new viruses. They
immediately build antidotes into their software updates. Assuming the
warning is not a hoax (it almost certainly is), an antidote would have
been developed ages ago.

Same goes for urban legends. Bill Gates giving away money. Poodles in
microwaves. Needles in movie theater seats. Busy people will not
appreciate getting this stuff from you.

You can always check virus warnings and urban legends on the Internet.
Hoaxbusters is a good place to start: http://hoaxbusters.ciac.org/
Or Snopes www.snopes.com

5. Moving too quickly
Careless grammar and misspellings will undermine the most important
message. Sure, you're in a hurry. But if your recipient has to e-mail you
for a clarification, you'll end up wasting a lot of time.

Take the time to be sure that any attachments are actually attached. And
be sure you're sending the e-mail to the correct person. If you're writing
to someone about a third party, don't send the e-mail to the third party.
That's easy to do, and can be very embarrassing.

6. Falsifying the return address
If you're sending something unpleasant, don't bother using a false return
address. The e-mail can be traced back to your Internet service provider
or even, your own computer. It's all in the e-mail header.

All major e-mail programs can display header information. Here's how to
see the headers of an e-mail:

In America Online, click the Details button.
In Microsoft Outlook, click View and Options.
In Microsoft Outlook Express, click File, Properties and the
Details tab.
In Eudora, click the Blah Blah button.
In Netscape, click View and Message Source.

The sender's revealing information begin with "Received:."
The originating computer is in the bottom "Received:."

That section will have an Internet Protocol (IP) number, such as
124.213.45.11. While the IP number is probably assigned to the sender's
Internet service provider, the ISP will be able to identify the sender
using that number.

Remember the header if you're tempted to send an anonymous e-mail. You are
less anonymous than you think.




Kim Komando Show Home Page: http://www.komando.com






Christopher A. Young
Learn more about Jesus
www.lds.org
.

"HVAC Guy" <HV...@Guy.com> wrote in message news:4F1A4A24...@Guy.com...

Grumpy

unread,
Jan 21, 2012, 11:56:25 AM1/21/12
to
Maybe I am bozo but you Sir is professor of powder room

I do not think that explanation is required!!!




"HVAC Guy" <HV...@Guy.com> wrote in message news:4F1A4A24...@Guy.com...

Daniel who wants to know

unread,
Jan 21, 2012, 10:11:09 PM1/21/12
to

"Grumpy" <t.s...@verizon.net> wrote in message
news:u5adnU77Ge6R7YTS...@giganews.com...
>
> Ok enough of this crap apparently your cheepy Tst is much more sensitive

That's what I thought at first so I wedged some plumber's putty in the
corner where the thermistor is located (it sits epoxied into a small recess
in the bottom left corner of the plastic housing) to add thermal mass, this
showed no change. Besides have you seen how fast a meat thermometer reacts
to temp changes? In air it only takes a few seconds per degree for a small
change, in meat they don't call them "instant read" for nothing.

> Than the others, to make it more stable you can cover Tst with something

I thought about also putting a clear storage bowl or one of those
anti-tamper plastic boxes over it.

> To see how much of effect will have, or/and if you have forced air heating
>
> Make sure that your duct discharge is not blowing on to Tst.

Nope, the supplies are on the other side of the room.


The Daring Dufas

unread,
Jan 21, 2012, 11:29:29 PM1/21/12
to
I'm afraid I didn't follow this thread that closely but did anyone
mention making sure any holes in the wall behind the T-stat were sealed?
That would be the first thing I always look for. I've found that even
the tiniest holes can let in enough air to screw with an electronic
sensor. Even air getting past/through the little plastic anchors for
the mounting screws. o_O

TDD

Daniel who wants to know

unread,
Jan 23, 2012, 4:40:22 AM1/23/12
to
"The Daring Dufas" <the-dari...@stinky.net> wrote in message
news:jfg3bv$a8t$1...@dont-email.me...
>
> I'm afraid I didn't follow this thread that closely but did anyone mention
> making sure any holes in the wall behind the T-stat were sealed?
> That would be the first thing I always look for. I've found that even
> the tiniest holes can let in enough air to screw with an electronic
> sensor. Even air getting past/through the little plastic anchors for
> the mounting screws. o_O
>
> TDD
>

In my case that is covered too, the thermostat is mounted to a paneling wall
of the closet that the furnace is in, the walls are bare studs inside the
closet, and the furnace is direct return instead of ducted with 2 20x25
filters in an A frame shape on top (it is a downflow), IE the area behind
the thermostat is conditioned space.


The Daring Dufas

unread,
Jan 24, 2012, 11:30:12 PM1/24/12
to
Cool! No pun intended. ^_^

TDD

Dorothy

unread,
May 27, 2018, 12:44:04 PM5/27/18
to
replying to HVAC Guy, Dorothy wrote:
Can you still purchase this thermostat

--
for full context, visit https://www.homeownershub.com/hvac/honeywell-magicstat-thermostat-questions-about-jumper-set-45521-.htm


Don Wiss

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May 27, 2018, 6:16:21 PM5/27/18
to
On Sun, 27 May 2018 16:44:02 GMT, Dorothy asked:

>replying to HVAC Guy, Dorothy wrote:
>Can you still purchase this thermostat

Silly question. Of course not. That Honeywell MagicStat is 19 to 21 years
old! Technology has moved on.

But if you really want old technology, you can find the ancient models for
sale on eBay.

Don. www.donwiss.com (e-mail link at home page bottom).
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