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tincup0007 · Oct 1, 2008, 06:54 PM

Sorry for the 2nd podst but my original title really didn't do this beast justice. We have a Yorkl 5kw A?C& Elect heat unit . Originally the condensing unit would not come on due to a broken wire on the emergency pan overflow switch. That was repaired and now the blower will not turn on and the cond unit runs constantly. Even if the stat is in the "off" position. Only way to stop iyt is to activate the pan switch or disconnect 24v that feeds the switch to the contactor coil outside.

Also, now the Blower will not come on at all, unless you jump from the Red 24v term on the control board to the Blue wire on the "G" terminal on the control board. If you jump it the fan relay will energize and the blowe will run for approx. 1minute & then shut off unless you leave the jumper on and then it won't shut off. We replacedd the control board and the t-stat BUT NOTHING HAS CHANGED> also no sure about the wiring on the stat.

There are 4 wires on the system red, white, yellow, blue the new stat is also a white rodgers like the old one, but w/different terminals: there is rc/rh (jumpered) G, W, AND Y with al yellow wire attached. We could PLEASE USE SOM HELP< It's AWFUL HOT STILL
Thanks in advance!

MarkwithaK · Oct 1, 2008, 07:49 PM

Are you certain that you bought a stat for a heat pump? In the set-up (or on the stat) did you set it to operate electric heat?

KISS · Oct 1, 2008, 08:24 PM

Two confusing to follow.

Mark:

Electric heat is different than a heat pump. Because it's labeled 5 kW, I'd suspece electric heat. It also reads as AC and electric heat when you clean up the gibberish.

If you replaced the electric heat stat for a "conventional fossel fuel system", AC should work properly, but heat will not. The fan won't come on in heat mide.

Is that your symptom?

MarkwithaK · Oct 2, 2008, 06:13 PM

Yes I am well aware of he differences between electric heat and heat pumps. The reason I brought up the heat pump stat is simply because most heat pump systems will have supplemental electric heat in the air handler since the pump is not very effective once the outdoor temp drops below about 40 degrees.

KISS · Oct 2, 2008, 06:33 PM

Yea, but what about "Electric furnaces" No heat pump at all. They a re stupid, but they do exist.

AC Direct - FAQ's - Sizing Your Electric Furnace

MarkwithaK · Oct 2, 2008, 06:46 PM

Oh I know. I have found over the years that a surprising number of home owners have no clue as to what equipment they have. One of my clients is a large hotel with about 75% of their rooms operating with heat pumps. During a recent remodel the majority were all rewired wrong at the stat and some had an incompatible stat installed.