Furnace won't shut off

Problems related to residential installations.

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Furnace won't shut off

Post by drosera » Sat Dec 24, 2011 1:22 pm


We have an Olsen bcl-120s furnace and a York model thermopump. These are connected to a Robertshaw thermostat for bi energy regulation. At -12 Celsius, the furnace is supposed to be the source of heat for our home. However, when this happens, the furnace no longer follows the thermostat settings and burns non-stop, only pausing to prevent itself overheating. Our house overheats terribly. We have been looking online at wiring diagrams to see if we could diagnose/fix the problem ourselves, but haven't found anything helpful.

This only started happening after a service technician rewired the thermostat.

Can anyone suggest something to help us?

Thank you.

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- Furnace won't shut off

Post by Freon » Sat Dec 24, 2011 10:15 pm

Simple answer... call that specific technician back since he knows what he did and you can tell him what the result was of his wiring.

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- Furnace won't shut off

Post by gibby » Fri Jan 20, 2012 8:24 pm

if tech won't return , pull stat off wall and make sure wires are not touching one another, check W wire may be touching on G

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- Furnace won't shut off

Post by how » Fri Jan 20, 2012 8:34 pm

Would not a crossed connection between R & W be the cause of a constant call for heat. All the electronic in the thermostat only connect the power supply coming to the thermostat to power the heating between these two connections. All the other wires are just aux functions.

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