wolfcub

I have a Honeywell T8411R Thermostat for my Goodman Split System unit. I have two Goodman's actually on seperate thermostats (both the T8411R) The units have 2 stage heating (regular and then the heat strips, and one cooling stage.

They are the most unreliable piece of garbage I have ever seen, can anyone reccommend a thermostat that is compatible to the above requirements that is also programmable??

Thanks

HVAC Doc

Personally I prefer White-Rodgers line of thermostats if I am not using a specialty stat such as the Infinity or Thermidistat. I used to use Honeywell all the time and then started having issues with many of their products and the T8700 series ate my lunch in warranty changeout. Here is a link to their product line for heat pumps with their Programmable, non-programmable and mechanical line all together for comparison. There are many many choices out there but one line to steer away from are Lux/Hunter stats. Many professionals will tell you (and it will be the truth) they are cheap cheap cheap line that will make your Honeywell's look like angels. Good luck!

http://www.white-rodgers.com/homeown.../thermo_04.htm

wolfcub

Thanks for the response, I will check them out. One other question.

I have had non-stop problems with one of my units since its installation by Weathermaster HVAC. The problems have been thier fault and for the most part I have been able to get them fixed. My question is:

I know Heat Pumps are notoriuos for not being efficient, however, my upstaris one whenever it gets above 90 dgress stops "catching" the temp I have it set at. Example: If it is set at 78 degrees, then it runs all day and never goes below 79 degrees. Again I know they are ineficient units but from what I understand they should at least get to the temp it is set at and shut off breifly and then come back on. If this is not the case then what would be the point of having a thermostat?? Is this true or am I just SOL once we hit 90 degress.

PS: The downstairs unit works the way I believe it should.

Thanks again

HVAC Doc

Alot of your problems upstairs could be due to insulation in the attic (or lack there of) or poorly placed/lack of return air. My home was built in the mid 70's and although I have an excellent duct system and brand new properly sized equipment, in the heat of the day (95+ days), my system will either run a few hours before set point (I keep mine at 72 year round) or when the temp climbs run all day a degree above and not shut off till late evening. Return systems for upstairs not only have to be adequate for the rooms upstairs, but also to handle the heat that normally rises from a lower level. Have you had another company out maybe to check over the system? It is possible that you could have some deficiency due to over/undercharge of the refrigerant. Insulation though would be the first key area I looked at though as an educated guess sight unseen. As for being inefficient, that primarily has to do with the heating cycle of heat pumps and the lower the temp drops, the more they run vs. heat put out. Newer units (5 yrs. and less) do a much better job and can do well into the 20 deg. range.

wolfcub

So they have replaced my compressor due to the fact that when they installed the unit they forgot to put in a piston and it ran without one for a couple moths. they feel that they compressor may have been damaged.

In addition, they have installed a TXV valve on the air handler. These seem to have helped the unit begin to cool to the set point thorughout the day however, now when I feel the air coming out of the vents sometimes it is luke warm and other times it is obviously colder. These changes happen within minutes of each other and IS NOT a result of the unit just coming on or shutting off. It is occurring right in the middle of the cooling cycle.

My question is, does the TXV valve have an adjustment on it that may be causing this and what exactly does the TXV valve do??

HVAC Doc

Most residential TXV's are non-adjustable. I would guess either it isn't charged properly (the unit) or they may have not secured the sensing bulb good or in the proper position on the suction line. The system should be charged by a method called subcooling. They didn't put the piston AND TXV in did they? If they did, the piston needs to be removed. A TXV is better than a piston in the fact that unlike a piston which meters in a specific amount of refrigerant regardless of load, a TXV opens and closes to adjust the amount of refrigerant needed to maintain a proper superheat.

wolfcub

No they actually took out the piston that they put in after they had realized they forgot it when the unit was uinstalled. They then installed the TXV. When they charged it, they chraged it by weight becasue the unit had been competely drained.

If the unit was not charged right I would not think that it would blow cool sometimes but then not others. In the past, it has just stayed luke warm.


Could this opening and closing be what is casing it to feel cooler one minute and less cool another??

HVAC Doc

If the TXV has to "hunt" for refrigerant due to the fact it is having liquid and gas refrigerant, yes it will cause the unit to cool for a bit then be warm the cool again. A properly charged system the TXV will not do this and your cold air will be continuous. Yes they may have weighed in the charge but how much additional lineset length do you have over the factory rating. Many units have X amount of charge for X amount of lineset then you have to add so many ozs. for each additional foot. Also, if the sensing bulb on the TXV is not secured properly making good contact and in the proper position as well as insulated, the TXV will not be able to adjust correctly. A properly working TXV will not give you any indication on it's opening and closing by making your air cold then warm then cold then warm etc.

wolfcub

Thanks for the Info. I have spoken with them and they are going to come back out and check the charge. Will keep you posted.

stephenc54

Greetings I too also have a Goodman Spit Sytem. In fact its the CLT24-1/-1B for the compressor. The air handler is ARPT 032 .. So far the T8411r seems to be doing fine. I called Goodman about the sometimes cool air changing from luke warm, they stated the defrost mode may be kicking in. This happend alot when the temp was aound 40-45 degress outside. I was complex i live in the northeast and minus degress temperature the luke warm air was a bit cooler but never got cold and neither did the freon line that leads into the air handler from the roof. I am puzzled about that but for the set point it seems to be quite efficent.
At the time of installation my unit appeared to be charged properly. My unit works alot of cycles when the temp is down around the 25 degree area. It really worked alot when the wind chill was down to 14 degress it heated for an average of 15 min cycle and 10 min rest in between cycles. I asked a few of my buddies about the 8411R and they stated it seems to be ok.
Let me know your thoughts anyone