Houston Texas. Very Hot 5 months of the year, Cold for 1 month, and nice weather for 3 months in Spring, and 3 months in Fall.
Two-story house. Dual systems of AC/Heat.
Each system was installed as all one brand, a Heat Pump (Compressor, etc) on the outside, and Evaporator coils, Gas Heater/Furnace, Fan, and "Electrical Interface Box" on the inside in the attic.
After about 10 years, from when the house was new, the Evaporator coil on one of the systems leaked. I called the company specializing in this brand (Starts with a "C" and the founder helped invent A/C) and had the Evaporator coil unit replaced. It was very expensive in my opinion - but they did a good job.
3 years later, the Compressor in one of the Heat Pumps went out. Because in Houston everything rusts, and the other compressor in the other unit had rust (these units had the compressors touching the ground) I knew the other compressor unit was about to go.
So, instead of calling the "expensive company" I shopped around. Finding another company I believed I could trust, they gave me a very good deal on replacing both the whole Heat Pump / Compressor Units. But the brand was not the same brand I had before. (Brand starts with "L," company started in Iowa) However, they assured me the units would "interface correctly and match up".
These compressor units are not on the ground, and the AC worked fine - in a very hot summer.
However, next, my other Evaporator coil started leaking, and now needed to be replaced. Because of the good deal on the compressor/AC units, I called the previous company back who favors "L" products. They replaced the Evaporator coil with an "L" unit.
Everything was working fine for AC in a very hot summer. But, after about several weeks of not using the AC in the Fall, we have a cold front come through.
I switched the thermostat on both systems over to "Heat" and fire up both Gas Heaters. Everything *seems* to be working fine on both, as I get that "burning smell" when the dust in the heater is cleared away.
However, soon after when it gets very cold, I notice that both heater units are not heating. They cycle on and off very fast compared to the way they used to.
So I called previous company back, and they said both "electrical interfaces" are "broken" and need to be replaced. It seemed very expensive for some electrical parts.
I'm not sure, but I think this is the "Control box" There is one box with about a dozen wires coming into it. They are noted by:
WF RF GF C YT ET GT OT YHP EHP OHP R
1.. What are the odds both "electrical interfaces" go out at the same time, when I start using the heater?
2.. Did I make a big mistake by not going with the same "brand" of compressor/Heat Pump system?
3.. In other words, did the new "L" system not "interface properly" the heat Pump outside, with the Heater/Gas Furnace inside?
4.. Does the company that installed the new brand of Heat Pump/AC have any responsibility to make sure the heater system works with it?
I guess I will have to pay to get this fixed. But I trying to decide which company to go with - Company who specializes in "C" products (which installed the heater/ EIB originally) or company who specializes in "L" products which I thought I liked.
Cliff in Houston