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Comfort Specialist
Comfort Specialist, HVAC Technician
Category: HVAC
Satisfied Customers: 1368
Experience:  Master Lic. holder for HVAC & Gas, Contractor, Estimator, Designer, Air Balance Certified, LG Master Commissioner, UNC Cert. holder for Industrial Ventilation
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Our Trane furnace sometimes gets up to temp then for the next

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Our Trane furnace sometimes gets up to temp then for the next 5 to 10 minutes blows cold air before it shuts off. My husband thinks that it is the taystat 340, 350 thermostat. Is there any way to know if it is the thermostat before we pay the money for a new one? He has pulled it off the wall so we have absolutely no heat at all.

Wvfan79 :

Hello there! I'm Norman but you can call me Norm. Let's see what I can do to get you some answers today. I'm ready to get started whenever you are.

Wvfan79 :

When you catch the system blower running after the demand for heat does pulling the thermostat from the wall shut the blower down or does it keep running even after you pull the thermostat?

Customer:

It continues to run until cycle is complete.

Wvfan79 :

Then the problem is in the system not the thermostat.

Wvfan79 :

If the thermostat fan relay was stuck you'd be able to pull it from the wall and it would stop immediately.

Customer:

Do you have any idea what the problem might be, it doesn't do it all the time?

Wvfan79 :

Sounds like the fan relay in the furnace. Do you happen to have the model number of your furnace?

Customer:

Now since my husband tried to take the cover off the thermostat he can't get the cover to lock in place again and now there is no lcd read out. Model # XXXXX

Wvfan79 :

He may need to put the bottom or top in first then swing the opposite side in to lock in place.

Customer:

He was only successful in pulling the top of the cover away from the thermostat.

Wvfan79 :

As for the furnace it will have a control board with built in fan relay. The board will have 3 large black boxes built onto the board. If he can get it to start and stick again we can try tapping on the black fan relay and see if it immediately frees up. If not the board will likely need to be replaced. Now this board does have a heating fan off delay but it's a max of 180 seconds. This would be normal operation though, it wouldn't just start on it's own.

Wvfan79 :

He probably needs to take it the rest of the way off first.

Wvfan79 :

Tell him to snap the bottom loose then pull it way from the wall. May take a tug.

Wvfan79 :

Those thermostats can be a pain some times.

Customer:

I am confused, are we talking about the cover to the thermostat or the fan relay?

Wvfan79 :

Sorry.

Wvfan79 :

The paragraph was about the relay. The last 3 lines were about the thermostat.

Customer:

He doesn't have a problem with pulling it away from the wall, he has it in his hand right now. It is the cover to the thermostat the he forced the top part away from the main box.

Wvfan79 :

I'm not sure I'm understanding what he's done. You can post a picture of it using the paper clip icon below.

Customer:

I am sorry but I don't have the ability to do that right now. What I am referring to is the sealed (was sealed) unit. He wedged a flat head in the top and pulled it loose then when he found out that he could pull off the entire box on the back of the sealed unit it said not to remove the two screws that is keeping the rest of the cover from coming off. I guess you would call it the face plate.

Wvfan79 :

Ah, and now when he puts it back on it won't light up?

Customer:

Correct!

Wvfan79 :

Ok. Unfortunately it's not meant to come apart that way so it may very well be broken. We can move forward with diagnostics but ultimately it will need to be replaced or working.

Wvfan79 :

If he wants to move forward we need to pull the R and W wire loose and twist them together which would act as the thermostat calling for heat. Then he would need to take them apart and get the blower stuck again. At that point we would do the part with the relays above. This will take two people and would be much easier with a working thermostat.

Customer:

That is just what I figured, he has the patients of a pea.

Wvfan79 :

I think we all do.

Wvfan79 :

My wife would concur.

Customer:

There is no guarantee that it will stick again right now. Because it doesn't happen all the time there is no telling when it might stick again.

Wvfan79 :

Ah. Well to ensure you, I'm fairly certain it was never the thermostat if pulling it off didn't stop the fan. I would suggest getting to the board and trying the test I suggested. If that doesn't work we'd want to check one limit switch built into the furnace to ensure it's not that. After that I'd have you replace the furnace control board.

Wvfan79 :

It would get pretty technical once we get inside the furnace and start diagnosing.

Customer:

Right now it is (I assume working off what we had the thermostat sat at before he did what he did and it is not sticking right now.

Wvfan79 :

I understand. If you get a new thermostat and want to proceed i can guide him. Or if you'd like to call in a tech to your home I'd understand. Either way I'm here to help.

Customer:

He is shying away from messing with the furnace, he is too unsure of what he is doing. We will probably need to go ahead and call in a tech. Do you have any best guess at what we might be looking at cost wise for the repair? I know that the thermostat is going to run around $70.00?

Wvfan79 :

Let me look up the board cost for you.

Customer:

Sounds good!

Wvfan79 :

If you are truely looking at a failed board you will probably see it cost a couple hundred plus a diagnostic charge.

Wvfan79 :

Depending on the company you use it may be 300 total.

Wvfan79 :

There will be some who charge a fortune for the same repair so don't be surprised.

Customer:

This is not good news. We live in Central City, Colorado, do you know of any company's that are good and won't try to rip us off? We probably (for now) will replace the thermostat but wait on the real problem because we can't pay for the repairs right now.

Wvfan79 :

What is your zip code?

Customer:

80427

Wvfan79 :

Here are 3 ACCA certified contractors. ACCA certification isn't a sure thing for quality contractors but it's a good start...

Wvfan79 :




















View DetailsHeatmiser, LLC
phone:(NNN) NNN-NNNNbr/>
14.11 miles


View DetailsSave Home Heat Co., Inc.
phone:(NNN) NNN-NNNNbr/>
20.28 miles


View DetailsElkhorn Heating & Air Conditioning Inc.
phone:(NNN) NNN-NNNNbr/>
20.37 miles

Wvfan79 :

Was there anything else I can do for you today?

Customer:

Thank you so much for your help I truly do appreciate it.

Wvfan79 :

No problem at all. Please do not hesitate to reply if you have questions or comments. Should and when you find the information you require, and are satisfied with my assistance please remember to rate your experience so that I am credited with providing you outstanding customer service. Ratings lower than 3 are negative. I'm very glad I could help you! If you ever need help in the future please bookmark my personal link and visit me again. I'd be glad to help.http://www.justanswer.com/home-improvement/expert-its-norm/.

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