Air conditioning question (safety, drain, hot)

[gettinoutofjersey]

This thermo does not have a backup battery

if i were to bet i would say you have a bad thermostat. even with a battery it should be getting the 24 volts from the transformer. i would go buy a new thermostat. swap the wires one at a time. the designators are universal from one stat to another. some times the wire colors are off so pay attention to the terminals that it comes off from on the old stat.

as i said earlier i have seen and experienced where the wire on the control (at air handler) was broken and laying against the terminal screw. it is one strand bell wire that when stripped usually gets nicked and creates a weak spot where it cracks. then depending on the vibration and where the wire is it makes contact or does not.

usually when a transformer goes it goes.

thats my best guess. that is why they make multimeters to take the guess work out of it.

let us know how you make out.

[debvic]

My husband asked a neighbor down the block about our ac issue and he gave us a suggestion. Check to see if the unit was draining. If not a shut off sensor shuts the unit down when water reaches a certain level at the condenser area. And sure enough it was clogged and not draining. We so far have not gotten the clog out. We tried using some water under pressure from the hose outside and tried using the shop vac to loosen the clog.Still clogged so we have poured bleach down the drain pipe hoping overnight it will dissolve whatever is in there. Thx for all your help, if anyone knows how to unclog this drain pipe that would be a help

[Randy Forbes]

(laughs to self) Well I'll be!

I'm puzzled as to why the t/stat display would blank out though, all the level sensor has to do is interrupt the call for cooling...

... either the electrician didn't care what wire was interrupted to shut down the unit, or he did it that way to alert the consumer there was a problem. I hope it was the latter

[debvic]

Originally Posted by Randy Forbes

(laughs to self) Well I'll be!

I'm puzzled as to why the t/stat display would blank out though, all the level sensor has to do is interrupt the call for cooling...

... either the electrician didn't care what wire was interrupted to shut down the unit, or he did it that way to alert the consumer there was a problem. I hope it was the latter

You know I don't know the answer to that but today we got the clog out and the unit is working fine. I am just glad it was a simple cheap fix!

[Randy Forbes]

That's the important thing, you're keeping cool! Glad it was so simple.

[tommy-105]

Originally Posted by Big House

I had a similar problem once. I didn't know how to use a humidistat. I hired an HVAC guy to come show me how to se it up. What I learned is you leave the humidistat to full "on" when you want to use your HVAC system. you set it to 60 or 80 when you leave for a long trip, it will work automatically from there keeping your house tempered and prevents mold from growing while you're away, but doesn't let your system run all the time.

I hope that helps. My HVAC guy - Joe Casey with Florida Air. 941-766-1181

Actually, the proper settings on the humidistat are determined by how it was wired when installed. They can be wired in two ways (parallel or series). So the instructions above won't work for everybody.

Installing the humidistat in parallel with the thermostat is considered to be the preferred method, as it lets the two devices work independently. When set up this way, the humidistat needs to be set to "off" (not "full on"), for regular use of the system when the house is occupied.

These days, in the age of programmable thermostats, many people don't bother with a humidistat. They simply program a vacation mode into the thermostat, allowing the system to cycle for two hours every day while they're away. This might use a little more energy, but it's considered to be the most reliable defense against mold.

LCEC does a good job of explaining it here:http://www.lcec.net/tips/brochures/V...er%20Homes.pdf

Some customers, particularly those in our Florida service area, often express concern about mildew growth that occurs while they're away on vacation. Many have asked if using a humidistat to control their air conditioner will prevent mildew and save energy. Progress Energy has found that in most cases, a humidistat used in place of the regular air conditioner thermostat does not reduce energy use.
Humidistats - Progress Energy

It's nice to see that debvic was able to avoid the expense of a AC service call for something that was as simple as unclogging a drain. Algae build up in the lines is a constant problem down here, and service calls that turn out to be cloged drain lines yield a very high profit margin for the HVAC guys.

I like Randy's idea about powering the thermostat through the float switch as an alert, but chances are pretty good that it was by accident.

[Big House]

Originally Posted by debvic

You know I don't know the answer to that but today we got the clog out and the unit is working fine. I am just glad it was a simple cheap fix!

That's great - it pays to talk about things like that! My HVAC guy while he was here, installed a small capped offset on the vertical pipe on the condensate drain (its pvc and was very simple to install), he told me to pour a little bleach in once a month, and that will help keep the line clear. I probably wouldn't have thought of adding that little connection, unless he suggested it. I've never had a problem like you described where the unit would shut off - but it make sense. I thought the little connection that allows you to easily pour in a little bleach (on the condensate drain line) was a great idea, cost very little and makes it so convienient to maintain, and anyone can do that themselves.

[gettinoutofjersey]

hopefully that was not just coincidence that you experienced. i can see some sort of safety shutting down the system but not causing the thermostat to blank out. but then all that matters is that you are cool, especially today.

[loves2read]

our daughter had problem with mold clogging the line at the condo HVAC unit--and that was what they tried to remember to do--pour some bleach down it each month

forgot to ask her if they have done it lately...since they arent living there now

[debvic]

Originally Posted by gettinoutofjersey

hopefully that was not just coincidence that you experienced. i can see some sort of safety shutting down the system but not causing the thermostat to blank out. but then all that matters is that you are cool, especially today.

There is a pve pipe with a cap with a plug at the condenser collection tray that is wired to the ac control/thermostat.It is a safety device that in the case of a blockage shut the unit down to prevent water damage in your home.This is particularly important when the unit is in the attic. ours is in the garage. Now that we cleared the drain line everything is back to normal I am glad to say.