Problem with a Rheem, bet you can't figure it out

[millertime77]

Didnt mean to sound offensive. With float switch in pan and condensate pump float switch you are looking at 3 wire nuts, 24 volts hot from transformer to one side of switch(1),other side of that switch to second switch(2), through second switch to t-stat(3), then all you got is compressor(4), heat(5),fan(6), and common(7), so depending on whatever else you have going on it shouldn't be much more than that. Even with the fact that older people are more sensitive to temperature swings, it is still hard to imagine that someone is noticing a difference early in the morning, summertime, when the temp difference between inside and outside is minimal. He says the air feels warm at this time. There is no way the t-stat will let you make a w and y signal at the sametime, so I would think you can rule out the compressor and electric heat running at the same time. It sounds to me like the stat is satisfying and fan relay is sticking or he has fan setting to on. Only been doing service work for short period of time but these kind of problems are the worst to try and deal with because you obviously can't be there to witness the situation.

[truck12]

Didnt mean to sound offensive. With float switch in pan and condensate pump float switch you are looking at 3 wire nuts, 24 volts hot from transformer to one side of switch(1),other side of that switch to second switch(2), through second switch to t-stat(3), then all you got is compressor(4), heat(5),fan(6), and common(7), so depending on whatever else you have going on it shouldn't be much more than that. Even with the fact that older people are more sensitive to temperature swings, it is still hard to imagine that someone is noticing a difference early in the morning, summertime, when the temp difference between inside and outside is minimal. He says the air feels warm at this time. There is no way the t-stat will let you make a w and y signal at the sametime, so I would think you can rule out the compressor and electric heat running at the same time. It sounds to me like the stat is satisfying and fan relay is sticking or he has fan setting to on. Only been doing service work for short period of time but these kind of problems are the worst to try and deal with because you obviously can't be there to witness the situation.

Theres no condensate pump. Not sure what you're counting out up there.

From the t-stat theres R, W, G, Y1, Y2, C.
The float switch runs in series with red.
Theres R, C, Y1, Y2 outside. Plus an extension for those four.
So thats 15 because I forgot the t-stat common.
And I wouldn't be surprised if theres a splice with more wire nuts hidden near the a/h somewhere.

I've seen a lot of heat sequencers fail and hold the heat on. They're only glued together so if they get bumped and break, the pin inside no longer holds the contacts open and they close, turning the heat on whether the low voltage is connected or not.

[catmanacman]

Y1 and y2 switched

[kls-ccc]

You might want to invest in a couple of data loggers. supco makes some that do a decent job and don't cost a lot. If you get one that logs amps and volts, and one that does duel temps you should be able to catch this thing in the act.

Put the duel temp in the supply and return, put the amp probe on a power line to the elements and voltage to W. You will see what the room temp is doing, how well the A/C is cooling, if an element is coming on, if there is a call for heat, and what time exactly it all starts and when it quits. It's a whole lot easier on the hair line than scratchin your head wondering what's going on.

[killeentech]

Could it be in tstat settings " cycles per hour"?

[truck12]

The problem continued. Yesterday I went out with a board.
The guy says sometimes it happens when it rains, it usually happens in the morning. I was there at 8:30 and there was dew on the grass, the sun was coming up and heating the cond unit.

I took the cover off and sprayed a very light mist of water about four feet above the board, one shot out of a spray bottle. It hit the board and the entire cond unit shut off. It also put out a code 27 which was loss of high voltage, it had high voltage the whole time. Changed the board. We'll see what happens now.

[Artietech]

Love reading about these problems, posting to subscribe to post and waiting to see what the fix is.
Was also leaning to tstat issue or low voltage wire issue...

[Thorazine]

I ran across one once where the defrost board got confused. Bugs walking around on a poorly coated circuit portion. Did I mention I hate bugs?

[selfemployed]

The stat must be a RHC-TST305UNMS to work with the condensing unit/air handler you posted
The Accessory kit in the outdoor unit must be a RXME-A02 for install with only 2 stat wires to the outdoor unit.
I suggest meg ohming your stat wire from air handler to the outdoor unit.
Guessing you have checked all low voltage field wiring and kit wiring already.
Only other thing I can think of is some of the control wiring is near a power source ( 115/230v. ) that is being powered up at that time of day and is causing interferance with the controls signal.

[pacnw]

not sure if this will help or not.

friend of mine had a heat pump added to his oil furnace, by others before I was in the business, and they used a dual fuel board at the furnace.

randomly the fan would come on, no call for it or conditioning.

he had multiple techs out to check it and nothing ever found or determined, it was fine when they got there.

I looked it over when there for get together and did not see anything incorrect, just poorly configured, installed and cheap components.

turns out that they mounted the dual fuel board to foil insulated duct and the foil would move and make a "G" call. it was especially bad in high humidity.

it took me 2 visits to come up with this diagnosis. second visit blew the 3 amp fuse on board when wire touched the insulation. we left the board hanging away from the insulation and only periodic starts due to humidity.

got him a HW VisionPro 8000 series.

[truck12]

My point in the last post was that I duplicated the problem and replaced a part, then could no longer duplicate the problem.

[Snapperhead]

you look for spider webs on back of board ?

i guess u cant now .... you replaced the board

[Kevin Weaver]

i DIDN'T READ EVERY POST, SEEING THERE ARE A LOT. ON A 95 DEGREE DAY, BOTH STAGES WOULD LIKELY BE CALLING FOR COOLING AND IN THE MIDDLE OF THE NIGHT, ONLY STAGE 1. POSSIBLY SOMETHING WITH FIRST STAGE ONLY. IF YOU WANT TO FIGURE THIS ONE OUT YOUR GOING TO NEED THE CUSTOMERS HELP. IF HE CATCHES IT LIKE THAT, HAVE HIM GO TO OUTDOOR UNIT, FEEL THE PIPES. GATHER AS MUCH INFORMATION AS POSSIBLE, OR SET UP A TENT AND SPEND THE NIGHT LOL.