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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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I have a 3amp in line fuse on the in side of my air heat pump

This answer was rated:

I have a 3amp in line fuse on the in side of my air heat pump Mod. GQ3RC-030K that blows when I turn on the heat. It goes from the field terminal to the transformer.
I put a new honeywell RTHL2510/RTHL2410 series. I hoked the wires the same way the old one was wired.
What would cause that?

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 :

Hope you are doing well today.

Wvfan79 :

Was your old thermostat a RTHL2510/RTHL2410 as well or a different model?

Customer:

No but was a honeywell

Wvfan79 :

Ok, what color wires went to what terminals on the old thermostat? Do you stil lhav ethat?

Customer:

R red

Customer:

Y yeiiow

Customer:

G green W white

Wvfan79 :

And you didn't have a C wire before?

Customer:

B blue I think that is it

Wvfan79 :

I think that's what the problem. Pull the B loose and cap it. Then replace the fuse.

Customer:

I don't think so

Wvfan79 :

I'm sorry?

Customer:

Ok I'll try it

Wvfan79 :

Your old thermostat required a B (common). It's probably an older Trane unit. On this thermostat B is not for the common wire. It's for energizing a reversing valve in heating which you don't have. Therefore when your thermostat calls for heat it's directly shorting the common to the hot on the W terminal and blowing the fuse.

Customer:

So far it didn't blow the fuse but it takes a few min. for the thurmstat to kick in

Wvfan79 :

I'll be right here to help. Let me know how it's going.

Customer:

It seems to work and I can smell the heat coils heating up

Wvfan79 :

Nice.

Wvfan79 :

This is a common mistake when changing thermostats.

Customer:

I guess that is it thanks

Wvfan79 :

Can't blame you. You see B and think, okay needs to go to B on the new one.

Wvfan79 :

I'll hold tight here for another minute if you'd like?

Customer:

OK Color codes I think I'm old school on them BK black BRN brown B blue

Wvfan79 :

LOL, it happens.

Wvfan79 :

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/.

Customer:

I put a thermometer on the reg. and it it at 80 so it works

Wvfan79 :

Very good!

Customer:

Thank you

Wvfan79 :

You are very welcome!

Customer:

I guess rate you and go

Wvfan79 :

Unless you have other questions about this request. If not, a positive ratting would be appreciated before closing the window.

Customer:

Excellent Rate

Wvfan79 :

There should be a button below that you can use for the rating. Thanks so much.

Customer:

By

Wvfan79 :

Goodbye

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