TrueAir thermostat replacement revisited

HD4Mark · 07-29-2011, 03:17 PM

This thread is too old to respond to so I will continue on with a new one http://www.irv2.com/forums/f101/true...tat-31489.html

I am attempting to replace our True Air therm. I tried to find a couple of the ones mentioned and they seem to be not available or replaced with something else.

I looked at a bunch of them online and don't really care if they are programmable, just like it to work better but when you go up to 2 stage they are mostly anyway. After half a day of looking I would like to try a Hunter 44860 7 day programmable. Using Duners chart as a reference here are some questions. This is from Hunters PDF. Y1, Y2,G are a gimme. The red/white to RC/R I assume. The grounds to C, white (gas furnace) to W2 that is strapped to E. The connection left is the white/black the heat pump. Does this go on the B connection?

Then I am thinking Roadking might be right wiring the gray freeze leads in series with the red wire and RC/R.

This sound right?

HD4Mark · 08-02-2011, 05:54 AM

Here is an update. After reading a load of stuff and trying to decide what stat to use as a replacement I decided to go back to a True Air replacement. We aren't really that interested in a programmable set back, I just thought for the money I could get a better stat for less money. We don't even use the heat that much since the idea of having the MH is to go somewhere warm when it is cold out.

I ordered a 6535-3442 that is a direct replacement for the 6535-335 from makariosrv.com for $112. It is noted that the orange wire is not needed and to cut it off. Confused by this since the orange controls the 2nd compressor I emailed them a question. Got back to me the next business day and tried to explain but it was still not getting it so I called and spoke with Dennis that replied to my email. The confusion is this: The plug for the gas furnace control on the replacement has 4 pin, the original 3. You have to cut the plug off and splice on your three and leave the orange/white not the orange cut. He said he will have that corrected.

Also just for information. The 9 pin plug that goes to the heat pump will be missing one pin. It is one of the gray wires that is connected to the freeze circuit. Where the other gray goes will be green wire to the stat. This plug stays intact so there should be no problem with that. Winnebago's end toward the heat pump has your choice of yellow wires. They seem to really like yellow wire.

I was looking at stats that were pushing $100 so the $112 didn't hurt too bad and this one will almost be plug and play. Makarios customer service was great BTW. I will post a review after receiving the new one.

cbeierl · 08-02-2011, 08:52 PM

Quote:

Originally Posted by HD4Mark

... Winnebago's end toward the heat pump has your choice of yellow wires. They seem to really like yellow wire.
...

But note that all of Winnebago's yellow wires are labeled every few inches, so you should be able to consult the online wiring diagrams to confirm what's what.

HD4Mark · 08-03-2011, 06:20 AM

Quote:

Originally Posted by cbeierl

But note that all of Winnebago's yellow wires are labeled every few inches, so you should be able to consult the online wiring diagrams to confirm what's what.

Good to know Chris and thanks. I wondered how they could tell what went to what.

SVTotem · 08-03-2011, 06:59 AM

I paid the few dollars for the adapter cable that allows direct hook up of the newer version thermostat. It made the replacement straight forward and it has worked perfectly. Thermostat and pigtail were purchased from Lichtsinn Motors whose phone support was also very good. Cost was similar to yours.

HD4Mark · 08-03-2011, 07:07 AM

Quote:

Originally Posted by SVTotem

I paid the few dollars for the adapter cable that allows direct hook up of the newer version thermostat. It made the replacement straight forward and it has worked perfectly. Thermostat and pigtail were purchased from Lichtsinn Motors whose phone support was also very good. Cost was similar to yours.

Bill,
Can I ask what your old stat was doing that made you have to replace it? Ours was not reading the temp correctly and we believe it somehow shut down the second compressor even with a ten degree difference between the set temp and room temp.

SVTotem · 08-04-2011, 07:18 AM

In our case the display failed and A/C compressors would not come on. The fan could be turned on with the manual switch on the thermostat. I don't remember if I tried the furnace since it was last summer when this happened.

Hope this helps.

Harry B · 09-12-2011, 07:25 PM

Mark,

Is your new thermostat better able to maintain the set temperature? Mine works fine except for the the large swing (3-4 degrees) between start up and shutdown of both the heat and cooling and the occasional reset to 72 degrees. These seem to be a general problem on the original thermostats, so I have put up with it. As such my question, do I need to put up with it?

HD4Mark · 09-13-2011, 06:20 AM

Quote:

Originally Posted by Harry B

Mark,

Is your new thermostat better able to maintain the set temperature? Mine works fine except for the the large swing (3-4 degrees) between start up and shutdown of both the heat and cooling and the occasional reset to 72 degrees. These seem to be a general problem on the original thermostats, so I have put up with it. As such my question, do I need to put up with it?

Kind of hard to tell yet Harry. We only use the MH in the winter to escape the winter weather in central NY and occasional summer trip. I only ran it a couple of times to test. Might be my imagination but it seems to run both compressors more than the old one. The second one wouldn't kick on, even with a 10 degree difference between the ambient and set temp. Now both run even with only a couple. I can see this while plugged into 30A by watching the EMS panel. The tech that checked out the original noticed a great difference in the room temp by the thermostat that it read. You might want to check yours using any decent thermometer near the stat.

By accident we discovered what may have been the biggest problem we were having. The duct only a few feet from the unit was ripped open at a seam. It was hidden behind a panel in the rear cap and accessible from the engine compartment. DW noticed cold air blowing into the compartment. Removed a bunch of screws and two metal panels to reveal about a foot by a couple of inches that had been repaired before. Some foil tape, foil bubble insulation and real big wire ties fixed that.

Pepper2 · 11-13-2011, 02:24 PM

Quote:

Originally Posted by Harry B

Mark,

Is your new thermostat better able to maintain the set temperature? Mine works fine except for the the large swing (3-4 degrees) between start up and shutdown of both the heat and cooling and the occasional reset to 72 degrees. These seem to be a general problem on the original thermostats, so I have put up with it. As such my question, do I need to put up with it?

Our Sightseer has the thermostate mounted on the outside of the bathroom waal. With the bathroom door closed it gets very warm in the bathroom, which I thought might affect the thermostates operation. We now leave the door open and the temp. seems more constant.