OK... Here it goes! My parents have a double wide with a Coleman HVAC system... inside unit is model# EB23B. They bought a White-Rodgers 1F82-51 programmable thermostat and wanted to have it installed. I installed it. I took off the old coleman mechanical thermostat and the wires were simple. R, W, G, Y... the B was not connected. The new Thermostat has R, L, C, E, W2, G, Y, O/B. So the new thermostat is way complicated. I researched and found someone that had similar set up online and he said hook up...

HOME WIRING / THERMOSTAT
Red / R
Green / G
Yellow / Y
White / W2 --- (with jumper going to E)
And finally, go to inside unit and hook Blue wire up to Ground for Transformer and hook Blue wire to C on Thermostat.

I did this and it works... I think it runs excessively after reaching set temp... but it works!
The aux light comes on when heat is on.. Now, I want to know if this is FOR SURE the correct way to hook this up?

ALSO... just about 10 minutes ago inside unit started making noise... low humming, took cover off and the coils were frosted..

Can anyone please help with this.. if all else fails I can hook up old thermostat.

If you do not have a heat pump system then the only wires to hook up are the R,W,G,Y at the thermostat. The other wires you hooked up are wrong.

I would have to agree that if the old stat used the 4 comon low voltage wires for control, then the same 4 wires on the new stat should serve the same purpose.

One of the problems with modular homes as they now call them to get away from the stigma of calling them "trailers", is that they have sub-par components, and even more so in the HVAC department. In other words, the heating and cooling systems are junk. They are often put together as two systems, with two complete control systems and the wiring can definitely cause a headache, but...

You have said that you got it to work, and the blue wire that you hooked up was seemingly unessasary, as would be the jumper. I would remove those connections and try again, although this should not have cause the frozen coils, unless several conditions were met. I would assume that the outdoor unit kept running, after the stat was satisfied that it had reached the desired set point of the user and probably shut down the inside blower, and the blue wire and jumper, somehow backfed the outside contactor and kept the condenser running. In a cool moist condition, like at night or early morn, the coil probably froze up, as it had no hot air being blown across the indoor coil and hence had no heat for the condenser to condense and diperse, so it reached the dew point and below, and that is what probably caused your frozen coil.

Go back to the 4 wire configuration and if that does not cure all, and you still have frozen coils, then you need to go deeper in finding out all the facts, like the correct charge on the unit, and even the correct sizing of the evaporater to the condenser, right down to the proper sizing of the line set or copper tubes connecting the two.

I have often seen window units freeze up, and they are hermetically sealed, sized at the factory, and even if installed improperly, should run fine. If this happens, one should simply remove the power from the unit, allow it to thaw, and then simply turn it back on. Too many people make the mistake of installing a self piercing valve to check the charge, which will usually be spot on, and then have the problem of a leaking valve and end up making many more service calls.

My point, is that under certain ambient conditions, the AC unit will freeze up, even though there is nothing wrong. If this were to happen often, then you would have a problem to be addressed, but sometimes a frozen coil is just that, and simply needs to be defrosted.

Dan

Common wire is used to power stat(keep settings) if batteries in stat die, but I don't see how hooking to the GROUND of your transformer will do you any good.. I believe you have the wrong stat for your system, however if it works, it works. I would strongly suggest getting a one heat, one cool conventional thermostat.

Econ AC (Dan) thanks a lot for your talking me through... dad seemed to think he had a heat pump system, and so he bought a heat pump thermostat. Well... it seems he was wrong! Lol I hooked old thermostat back up and ordered a h1/c1 thermostat from honeywell... your spot on about coil frosting... OF COURSE the heat pump stat was telling a/c unit outside to stay on WHILE inside furnace is on. I understand A lot more now having read your and other peoples comments. Thank you for taking the time man.. appreciate it! AND last but not least.. thank you mygirlsdad, you are right as well! Wish me luck on the honeywell lmao

Yu can make a heatpump stat work, but those stats cost a lot more money than the common 4 wire stat and would be more confusing to hook up. I also run 5 wires when I do an install. On older stats used on newer systems, you would often have to run an isolation relay to stop a lot of problems on the early computer boards.

Most of the time, the first thing you should do is to check the power. Line voltage first and then control voltage out of the transformer. Remember that the transformer is just a iduction coil that converts power or line voltage to another voltage that can be used for something else, in most cases it will be control voltage or 24v in most residentail units.

I would also like to state, since the transformer is a simple induction coil, there is really no common on the control side and can be hooked up either way, just so you have all the components wired the same way. This can also be confusing to those new at this.

Dan

I would also like to state, since the transformer is a simple induction coil, there is really no common on the control side and can be hooked up either way, just so you have all the components wired the same way. This can also be confusing to those new at this.

I agree somewhat with the above statement but many other items are in play when it comes to transformers.

Just a side note here meant for all the HVAC servicemen on the board.

Polarity does exist on our cheap little 40VA transformers. As a simple test of that fact just take two transformers and power them up with 120 then combine the leeds. If it does not fry the weakest of the transformers then reverse one of the transformer leeds and it will. Now for most of us old guys we remember when thermostats did not have the RH and RC connections. Back in the day both the furnaces and outside units had separate transformers and in order to use one thermostat we had to do a transformer polarity check so we could use the same terminal on one thermostat for both the heat and A/C.

I am only mentioning the above for two reasons. After doing much research 10 years ago or so it was discovered that many furnace control boards were being replaced when they were not defective. Much of the cause of this was the fact that the low voltage feed was reversed polarity wise causing the board not to operate correctly. The real funny part of this is the fact that sometimes the furnace board would work fine for a year or two and then all of a sudden cause a problem. After so many returned boards the manufacturers wanted to find out the problem and as mentioned before the transformer polarity was causing many of the problems.

Most manufactures now mention in there instructions for the boards to try and reverse the low voltage leeds supplying the board to test for this condition. Depending how a transformer is wound weather CW or CCW will determine which leed is operating on a positive note.

The main reason to post this is to mention that in the next few years more electronics will be installed in residential and commercial HVAC equipment. We have been working on electronic expansion valves for quite some time to boost the never ending quest for higher SEER ratios. Below is a sample of a Sporlan/Parker control board for the electronic expansion valves. Pay close attention to the transformer polarity requirements in the wiring connections list. The transformers used in the testing were off the shelf cheap 40VA units that we see every day. Get prepared for the future since it is right around the corner.

http://www.parker.com/literature/Sporlan/Sporlan%20pdf%20files/Sporlan%20pdf%20100/SD-278_112008.pdf

As always, great info HVAC1000. Thanks. Always learning from you.

Ive noticed that many new control boards will give a flash code to let you know if polarity is reversed, or insufficient ground. Pretty nice option, but not always guaranteed to be correct.

I always feel the day is lost if I do not learn something new. I will be learning till the day I die. One thing nice about the industry is the fact that you can never no it all and I make sure I mention this in any class I am part of.