Educate Me Section
Educate Me/Home
James A/C Co./Home
Diagnosis of problems
Understanding refrigeration
Homeowner helpful hints
Filtration & More
Understanding thermostats
Outside units and safety
Indoor Coils and drains
Links & Search
Air Purification Products
Honeywell® Thermostats
COMPARE --
Humidifiers
Unit Heaters
HVACR TOOLS
Accessories
James A/C Co.
serving Do-It-Yourselfers since 1990.
Satisfying every customer....one at a time!
|
|
Call toll free 1-866-584-0355 or 1-903-759-2160
309 Patriot Circle, Longview, TX 75604-2240
THERMOSTATS PAGE TWO:
The things you can do to your thermostat are mostly only simple ones. A very
simple, but good, thing to do is periodically blow out the dust off the
moving parts, if it has any. Of course, do this gently, never with high
pressure air. Don't let dust restrict the movements of your electro-mechanical or mercury bulb thermostats. The current production models and most recent predecessors don't have moving parts. Almost every thermostat now is digital and electronic versus electro-mechanical.
You can check to see if the location of the thermostat is good.
Observe the following general rules when selecting a location:
- Locate it about 5 ft. above the floor. Recently, however government regulations require it to be place low enough for wheel chair access in all state and federally funded locations.
- Install it on a partition wall, not on an outside wall.
- Never expose it to direct light or heat from lamps, sun, fireplaces or
any temperature radiating equipment.
- Avoid locations close to doors that lead outside, windows, or
adjoining outside walls.
- Avoid locations close to air registers, or in the direct path of air
from them. However, near the location of the returning air grille is good.
- Make sure there are no pipes or duct work in that part of the wall
chosen for the thermostat location.
- Never locate it in a room that is warmer or cooler than the rest of
the home, such as the kitchen.
- Avoid locations with lack of air circulation, such as behind doors or
alcoves.
- The living or dining room is normally a good location provided there
is no cooking range or refrigerator on the opposite side of the wall.
Another very important thing to consider regarding the thermostat is its
mounting on the wall. If your thermostat contains a mercury bulb, then it MUST be level.
If it is magnetic switching contacts or if it is electronic, then it probably
doesn't matter. It can even be mounted upside down or sideways, because
these types do not depend on gravity to assist its movements.
Most thermostats contain two
major parts--the main body and a subbase. This round thermostat has an additional outer ring around the face. Any
mounting and leveling is done to the subbase and the body is simply attached
to the subbase and is therefore level. To level many of the types of
thermostats, simply lay some small level like a "torpedo" type on or hold
against the bottom of the thermostat and tighten the mounting screws when it
is at the level point.
|
The Honeywell round thermostat on the previous page requires a little different technique. The leveling is done to the subbase and
two posts are at the upper part of it on which you lay the leveling device.Notice also that there are several screw holes and some are slotted for leveling.Note: The newer digital thermostats don't require leveling except for aesthetics. They can even be mounted sideways and will work just a well, even though they may be more difficult to read or program. |
|
If you have any paperwork on the thermostat, please read it carefully
before making any adjustments or removal of screws, etc. If you don't, good
luck. Some thermostats have an outer facial cover. This may be
a rectangular, square or round ring (like the Honeywell T87 above). You need
to figure carefully how to remove this cover because some are hinged and others
just pull off and others are locked very well and require a special tool. But
most just pull one way or another off of the thermostat. Never force anything
on the thermostat. Rough handling may decrease its accuracy or break it. |
Be very careful not to break any mercury bulbs, because the hazards are
great. Mercury can be very dangerous if you contact it or it gets ingested.
If the bulb becomes broken, the mercury will run and splatter into little beads all
over the place. Special cleanup by professionals is required.
If you need to dispose of a mercury bulb, do not place it in the trash. Call
a local waste management facility and ask their advice or take it to any air
conditioning dealer and he will be glad to dispose of it properly for you.
Sometimes these mercury bulbs become cracked without spillage. The
contents (mercury) will become cloudy. This is a good sign that air has
gotten inside. It will work very poorly if this has occurred. Replace the
thermostat. Not a piece of it, but the whole thing. Models constantly change
and it is unlikely you will find a perfect replacement for individual parts
of a thermostat.
Don't forget that a thermostat has voltage to it, so remember to
unplug the control voltage source when you work on them. Be sure of this,
do not trust electricity to be forgiving if you err.
Now, let's get really technical.
Inside the thermostat just behind the outer cover of these types of thermostats you will see a heat anticipator. It looks something similar to
one of these two:
These adjustments are the heat anticipator. They are for the length of the
cycle of the heating, but sometimes there is one for the cooling.
But almost always, the cooling anticipator is a fixed resistor on the subbase.
It's a very critical measurement with special instruments for the professional.
Don't worry, you can set a replacement thermostat heat anticipator just like
the old one or you can make adjustments in very small increments as instructed
here.
- HEAT CYCLE TOO LONG--Set adjustable heater to a slightly lower dial setting. (1/2 division)
- HEAT CYCLE TOO SHORT--Set adjustable heater to a slightly higher dial setting (1/2) division)
If you have an amprobe (amperage measuring device *) you can measure it
very precisely like the professionals do.
|
The adjustable heat anticipator will burn out nearly instantly if this adjustment is set too
far to the low side or if while the voltage is available, you short the
circuit on the controlled device (like the automatic gas valve or a relay). You will have to buy another thermostat if you
burn out this anticipator. Follow these instructions carefully and use the pictures supplied here.
Adjustments may be variable from .15 to 1.5 and this is a calibrated scale
of amperage or current draw. |
Another good thing to watch for here is an excess of current. If your
thermostat is rated to a maximum of 1.5 and
your 10 loop reading is a 40
or 50, then you can be very sure you need to stop here, IMMEDIATELY turn off
the voltage supplying it and correct a problem in the controlled device
(the heater) before it burns out the anticipator. A relay or valve that
the thermostat is to control has a problem and needs replacement.
The 40 or 50 reading with the loop would indicate an actual draw of 4 or 5 amps of current. Most home and office units have transformers (40VA) that will only tolerate about 3.5 max. If you are dealing with a 20VA transformer, then it is about half that. THESE CURRENT LEVELS MAY HARM YOU. Be careful.
* Amprobe is a registered trademark ™ of United Dominion Co.
Click here
and send me your request by e–mail or phone.
1–866–584–0355 (toll free) or 903–759–2160 FAX 903–759–4605
If you have
comments or suggestions, please email me at James' A/C Co.
|
|
Honeywell®
VisionPro® IAQ
whole house control
Honeywell®
FocusPro
non-programmable
Honeywell®
VisionPro
Replacement for obsolete Chronotherm III/IV
Honeywell®
Electronic Air Cleaner
Honeywell®
Media Filters
Honeywell®
UV Lights & Bulbs
Honeywell®
Carbon Monoxide
Alarms
Honeywell®
Electronic Air Cleaner
Replacement Cells
Honeywell®
LineVoltPRO™
programmable
Honeywell
Rectangular Zone Dampers
Honeywell
Round Zone Dampers
Reznor
Infrared Heaters
|
