I have a Centralite Pearl 3000 thermostat and have suddenly had it do a “runaway” when it is set to heat. What I see:
- The thermostat makes a call for heat and the furnace (package air unit) starts and when it “runs away” the display goes dark and is unresponsive and it runs the heat continuously until you pull the thermostat face off to force a reset.
It has done this three times in the last 2 days with the first time it had gotten up to 86° before I woke up.
There were some changes before this but I don’t think they are related. I swapped out the 20 year old SEER 13 package unit for a SEER 16 package unit from the same manufacturer (Goodman). The new unit is multi stage so I hooked up the W2 and Y2 connections but I have since disconnected the W2 to see if that is related but the second and third runaway was without the W2.
The cooling side of things has been working normally but the first time I’ve need heat in half a year was when things went crazy.
Can anyone think of a condition that could make a Pearl 3000 lockup like that?
(In a month I’m going to be headed out of the country for 2 weeks and I’d prefer that the house not get to 140°. Probably going to find an old bimetal thermostat and wire it in series at a slightly higher temp to act as a safety.)