Ok... I have been dealing with this problem for sometime and with advice from this forum, I did have someone out here to take a look at it. Too bad that guy was a moron. So I am back with new information to see if someone who knows what they are doing can solve my problem without be having to pay people $100 bucks to make up things.

Here is my problem:

When I go to turn on my heat or AC, the thermostat clicks as if it is telling the unit to turn on. But nothing happens. If I turn the fan to on instead of auto (which should run no matter what) the thermostat clicks but nothing happens. If I go in my attic to my Ducane furnace and flip the breaker (a light switch connected to the unit) off for about 30 seconds and flip it back on, everything works great, until the unit switches off again.

When the repair man was out here the last time, I told him what was going on. He tried to turn on the thermostat and *click* nothing happened... Then he went in the attic and flipped the switch and everything started to work. He said, "Ok problem solved" when I said, "No, when it sits off for a bit, it will not come back on." He replied, "Well that is an intermittent problem that I can not diagnose unless it happens." I said, "It just happened!!" Well, you will have to have me back out when it happens again. And that will be $100 you owe for today and $100 for when we need to come back out!" Within 15 min of him leaving, I tried to switch it back on and *click* same problem. I tried to get him to turn around but he was going to another appointment and would have to schedule me for next week, at $100 inspection fee!" I hate getting hosed by people!!

So any thoughts on what this could be so I can get it taken care of, by another company the FIRST time they come out?!

How about a exact model number for you furnace? How about a brand and model number for your thermostat?

I remember your post from the last time. Looks like you got a service person who just does there job no matter what the outcome. Intermittent problems are the worst to figure out since the problem does not show all the time.

Also does your unit have a circuit board? Is it a gas furnace or a heat pump? Really need more info to get started at this point.

I do not know where to find the model number. I have checked all the writing on the exterior of the door and there is no model number. I have pulled each panel off and looked and there is no model number. The plaque on the outside just states Ducane. It is a gas furnace. I know that all the equipments is 10 Seer. I can find NO information on their site about any 10 seer equipment. I do not know what you mean by circuit board. It has the removable panels on the outside to access the interior electronics. There is a bunch of wires and a small circuit board. I can tell that they wires from the thermostat go into that board. The unit is about 7 years old.

As a time line, I reset it last night before typing my first post. It ran for about an hour or so, then shut off. It has been off now for about 8 hours and I just tried to turn on the AC and it comes on. So I will try it throughout the day and see if there is a trigger that I can find or how long it needs to stay off before it will not come on again.

Odds are it is a problem with that little circuit board with the t-state wires on it. That would be the only part other then the t-stat that would cause problems in the heat and cool mode both.

The model number on a ducane unit should be on a white sticker on the left side inside the top door of the unit.

I'll check right now... BTW: I forgot to add that the t-stat is a ritetemp programmable unit.

OK I should be on here for a little bit. Do you know if your t-stat has a built in time delay?

Nope, no white sticker other then the wiring diagram on the inside doors of the unit. I pulled off each of the three doors. I looked at the diagram and nothing on there says "model #XXXXXXX, Serial number XXXXXXX".

I thought about the t-stat being the problem but why would resetting the breaker up on the unit effect the t-stat? If the t-stat is not working, it should be independent of the breaker upstairs, correct. Also, I hear the click from the t-stat telling the unit to turn on. I would figure if I hear that click, the problem is outside the t-stat. But that is just my back-wards logic.

The t-stat is "ritetemp 8022C". I am looking in the manual for anything about a time delay.

The model will be on the furnace its self on the inside left or right, or in your case on the top or bottom. Sense yours is laying down. It is not on the back of the doors. To see if it is the t-stat or not. You can take it off so you can see the wires. Then put a jumper from r to w to see if the heat comes on. A jumper from r to g will see if the fan works and a jumper from r to y will do the ac. This will let us know if the t-state is the problem or the control board.

You are right... You think they could have made that in a better spot. It was upside down on the top, hidden by what I assume is the blower, since mine is laying down. Model number MPGA050B3. I just checked the t-stat again. Turned the fan to "On" and nothing happened... Tried to turn the AC on and nothing happened... So it looks like I am in the problem area again. So as such, I will try to mess with the t-stat to see if it comes on. You say to "jumper the wires", explain what you mean. I should just be able to take a piece of wire and touch it to the wire colors that you mentioned, right?

Yes a piece of wire, or just a pair on needle nose pliers will work. Just make sure not to hit the c terminal. That is a common wire and you may short something out if you bump it. But yes r to w for heat, ( r- g for fan try this first.) and r to y for ac

Ok... Nothing happens when I jumper any of those connections... Not even a spark. I did see something weird. There is an orange wire hooked up (maybe heat pump) but I have no heat pump in the home, just the gas furnace and the ac units outside.

Are you sure your outdoor ac is not a heat pump? Was there a wire on the E terminal, or W2?

I took my downstairs t-stat off to see its wiring and sure enough, no orange wire. I also tested to make sure that I was jumping correctly and it will turn on. I am sure if I reset the breaker up in the attic it will come on but I do not want to do that since it is not working and we can test other stuff. Should I take a volt meter to the r-g wire pair to see if there is any juice there?

I do not have an E or w2... only a w and there is the white wire there. Ya, it is a condenser unit outside. I am 99.9% positive.

Did you do your jumping at the t-stat or at the furnace? Also have you found your circuit board? If you did what you need to do is put the t-stat back on turn it to the fan on position. Then at the contol board in the attic with your volt meter check between the C termanal and the G terminal you should be getting 24-28 volts with the fan on the on position. Do you have the doors off the unit now?

Ok I will try that... Ya I have found where the wires enter the unit in the attic. I have two of the three doors off, the third door seems to have a switch on it that tells if that door is off and (I think) tells the unit not to turn on. That is what I assume, so that door is on right now.

Ok, I will test at the furnace and let you know... Thanks for all your help so far. Really, I do appreciate it!

No problem I wll wait to see what you find out

Oh you, I did my jumping at the t-stat

OK if you did your jumping at the t-stat. and it did not work the I will assume you will get power between c and g at the unit. Rember to turn the fan to the on position at the t-stat

Without resetting the breaker, I have 0A and 0V. Fan is in the On position too.

OK check between R and C for 28 volts

And your sure that door switch thing you was talking about is pressed in correct?

Well, the door is shut... I do not see how it can be pressed any dirrerent. It is screwed down...

Ya nada on the C-R readings. Remember, I have no reset the breaker yet. Should I reset it?

Nope not yet. Do you have a breaker up there you reset or like a light switch?

Light switch...

OK one last thing to check before you reset. Find the transformer.


http://americanhvacparts.com/Merchant2/graphics/00000001/Johnson%20Controls%20Y65.jpg

You should have 110 volts going into it and 28 volts coming out

Then after you do that I have anouther idea to try

Nada at the transformer. I took off the wire nuts on one end (white and black) and tested between them and got 0. I took off the wire nuts at the other end (red and green) and got nothing. Although the red and green were paired with different colors at the nut. But alas, nothing. I am getting more volts across my body right now according to my meter then this thing is.

OK then we have got to the problem then. Take off the door that has the switch wait 10 seconds then push the switch back in. you still have your fan set to on? The blower should come on when you push it back in. it will act as a reset to. If it does not then your problem is the light switch you have been resetting is going bad and not making contact or there is a lose wire in it.

Ok trying that now...

OK I will wait for your answer

Also before you reset the light switch check for 115 volts right there at the door switch!!

Dang it, I just got that door put back on... and it is a bugger to get screwed in! :)

No, no luck taking off the door and letting the door switch reset it. It does not appear that this thing is getting any juice!

This might be a dumb question but here it goes. Is there an internal sensor of some sort (almost like an internal fuse or breaker) that would be tripping but being reset once the light switch is turned off and then on?!

I guess I could check for power at the light switch. That scares me a bit because I have been known to electrocute myself from time to time. (Electricity was not my strong point in physics class) but If power is coming into one end of the switch but not leaving the other, then it is the switch right?!

Other then the door switch, and the light switch there is nothing else that would be keep power from going to the transformer you checked so yes if you check both sides of the light switch if there is not power on 1 side then it is deffenty the switch. Ps if it is going bad or has a lose wire. When you start to move it to check for the power the unit may come on.

Ok... One last trip up the stairs and up the ladder into the attic! :)

Lol, I know that must be a pain. But at least we are almost done

That did it... Wiggling the wire at the light switch made the unit come on. So it is the wiring in that switch... THANK YOU so much for your help. That is an easy fix that I should be able to do myself. Now, all that is left is to figure out if my compressor has a leak (since it was down to 40 PSI when last checked and refilled) and enjoy the cooling air this summer. This has been a nagging problem for almost a year and thank you for getting to the bottom of it!! Do you handle car AC too?! J/K :)

Yes I do car ac as well. Have a great day and make sure to turn the breaker off before messing with that switch. Glad I could help. Intermittant problems are always a pain I will be on later today and tomorrow if you still have any more questions with this or your car. Have a good one Josh

Josh, if you ever have an problems with home appraisals or value questions, look me up!! Thanks so much!

I do have 1 question maybe you are fimilar with or can help. With

Send me a PM and I will answer what I can for you!!