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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 7991
Experience:  Furnace, A/C and heat pump specialist.
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I have a 4 ton Precedent roof top unit, Model YSC048E4HA1FD,

Customer Question

I have a 4 ton Precedent roof top unit, Model YSC048E4HA1FD, Serial###-##-####. Not heating. Immediately upon closing the disconnect at the unit, the burner inducer motor comes on and stays on. This is prior to the internet connected thermostat booting up so at the point the inducer motor comes on, there is no call for heat. I tried running it through the Test Mode by installing the jumper across LTB-Test 1 and LTB-Test 2 but the inducer motor immediately came on. I'm suspecting the ignition module is defective.
Thanks !
Bill Semanision
Neiman Marcus East Coast Distribution Center
Pittston, PA(###) ###-####email: ***@******.***
Submitted: 1 month ago.
Category: HVAC
Expert:  airheatman replied 1 month ago.

Bill does this one have a control board with an error light? And is igniter spark or hot surface?

Expert:  airheatman replied 1 month ago.

See legend below:

Customer: replied 1 month ago.
It does have a LED on the board and I have to check it when our weather improves somewhat. It is 5 degrees outside with a 20 mph wind. (the space that this RTU conditions is an interior space so it is not that critical)The ignitor is spark.Bill Semanision
Facility Engineering
The Neiman Marcus Group
East Coast Distribution Center*****Pittston, PA 18640(###) ###-#### (office)(###) ###-#### (mobile)
Expert:  airheatman replied 1 month ago.

Brrrrr.I understand that.Just come back to the question when it is warm enough for us to troubleshoot.

Customer: replied 9 days ago.
Finally able to get to the roof. There are two circuit boards. The left board is the ignitor board and that LED is flashing 5 times and the right board which is the main control board its LED is flashing 2 times. I have a photo of each board if that might help.
Expert:  airheatman replied 9 days ago.

If you are getting 5 flash code on ignition module.Turn power off and back on to reset board.If error still present replace board.It saying we have flame when we do not or should not.

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