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type2technician
type2technician, HVAC Technician
Category: HVAC
Satisfied Customers: 251
Experience:  Heating and a/c repairs
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I Have a Armstrong Ultra SX90 Up flow Furnace, hooked up with

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I Have a Armstrong Ultra SX90 Up flow Furnace, hooked up with heat-pump. Blower motor, and the induced draft motor running at the same time. Even with the Thermostat wiring disconnected the blower motor, and the induced draft motor are energized and running. Don't know why the relays would be energized.

type2technician :

It sounds like the control board in this system has gone bad.

Customer:

Just replaced with a new control board, does the same thing.

type2technician :

Check the low voltage wiring to make sure they are correct at the thermostat and at the control board on the furnace.

Customer:

Okay, just checked, seems correct.

type2technician :

Is the furnace control board light flashing any codes?

Customer:

This model does not have any code lights

type2technician :

Is the furnace lighting?

Customer:

No

type2technician :

Then this may be an indication that one of your limit switches is open.

type2technician :

Are you able to check the limits for continuity?

Customer:

Yes

type2technician :

Check all the limits switches. See if one of them is open.

Customer:

Okay

type2technician :

ok

Customer:

Open high limit;jumped seems to be working now. Thanks

type2technician :

No problem. You may need to replace that limit or try tapping on it to get it to close.

type2technician :

Please rate this session if you are satisfied with this service. Thanks.

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