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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 8430
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Bill, we have two RTU trane units YCD 150's and was not been

Customer Question

Hi Bill, we have two RTU trane units YCD 150's and was not been used for some time.
JA: Did you double-check the thermostat? And what about the unit's filters?
Customer: Both powered up and heats up as well shuts of with two flashes on trouble LED Lock out
JA: Do you plan on doing the work yourself?
Customer: yes ..
JA: Anything else we should know to help you best?
Customer: since both shows same feels some common reason.. k
Submitted: 8 months ago.
Category: HVAC
Expert:  Phil replied 8 months ago.

Hello, this is what I have on that system Click here

we can use it as a reference if the diagrams on page 14 and 15 match your units.

Expert:  Phil replied 8 months ago.

If these units are wired together, as shown on page 13, it may be a bad smoke detector in the supply or return as shown.... check each with an ohm meter until you find 3 of them reading the same resistance, in that case it will be the 4th thats bad if it reads differently.

Expert:  Phil replied 8 months ago.

Dust could have accumulated in the units when they were shut down for so long, and that could be what it setting off one of the smoke detectors.

Customer: replied 7 months ago.
Hello Phil,
Customer: replied 7 months ago.
are you getting my requests?
Expert:  Phil replied 7 months ago.

Hello again, I am not sure what you mean? but yes business goes on as usual although I have been taking it easy lately in order to study up on 3D CAD modeling after effects,

Can you clarify?

Customer: replied 7 months ago.
Thanks Phil, very nice to see you still pursue new stuff. You were very helpful.
I guess i was screwed by two threads and was chating on other one. Below was that.
if you can give any more clue great, payment is not an issue.
We know basic unit works burner fan etc, control not good. I did not see any extrnal sensors hooked up except smoke detector..
At present I like to get a parts manual, and a recommendation nearby knowledgable guy, also in case to call area code 60448
Last message below
Hello Phil,
Was on roof top unit , too cold and dark, sorry it took a while to get back with you.
Found these are not tied together, but has smoke detector each . Both were blocked by dirt.
Got access to one, and looks cleared that issue. I do really appreciate for the right tip gave.
One small issue still left .
After running a while it shut off heating , but came on itself after running a while and kept cycling.same way.
The LED blinks when it shuts off same like it is calling for heat?
Any possibilities?
I left since at least not cold any more.
Million thanks again.
Expert:  Phil replied 7 months ago.

Hello again, getting a parts manual for that older system will be difficult or impossible, and also not needed especially of you call in a local skilled HVAC contractor... these trouble shoot many brands and have no trouble sorting out the problem, then ordering anything they need from parts vendors, not using a parts manual or parts numbers.

The suppliers file it all under the unit brand and model number then locate the item by its description (such as gas valve or blower motor listed for that brand and model number)

THe two highest rated best established HVAC contractors in the area are:

Either one should have no problem at all diagnosing and repairing your Trane equipment.

And as you noticed, both units are behaving identically, most likely its a common exterior problem having nothing to do with the Trane internals, but some sort of common wiring issue.

Let me know how it goes.

Customer: replied 7 months ago.
Thanks Phil, I will let you know...
Expert:  Phil replied 7 months ago.

Great, please do not forget to rate my assistance! I will appreciate it and that will allow you any follow up you might need later.

Customer: replied 7 months ago.
For sure my friend, have a good one
Expert:  Phil replied 7 months ago.