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

Page 2 of 2  


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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
..

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.
------------------------------------
the magic was how it lined honeywells pockets...it was in the same class as hunter stats
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Totally agree . The Hunter wouldnt properly control anything beyond a .4 amp device in the heating mode.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Dave M." wrote:

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

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

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.