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1 vote

Advice on how to wire a 4 wire RGWY wifi thermostat to an old hvac with no c wire?

The top picture (with the timer) has noting to do with your HVAC. It is a airflow (ventilation) controller for your home, not for heating or cooling. On the new thermostat (model unknown) the ...
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HE furnace exhaust options

The square area of 3 inch pipe is 7.1sq inch The square are of one 2 inch pipe is 3.14 sq inch (total 6.3 for two 2 inch pipes) The r on 2 inch. pipe is 1 inch, and the r on 3 inch pipe is 1.5 inch (...
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Is 2 stage furnace worth it in dual fuel setup?

I have a similar system. I installed an 8 ton AC/Heat pump many years ago, with variable speed fans etc.I also added the electrostatic filters. I was was told that the only way to go was with electric ...
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Is 2 stage furnace worth it in dual fuel setup?

posting this as an answer bc of not enough space in comments. I'm not an HVAC expert, maybe others will contribute. But here goes: first, are you call it a "furnace", do you mean the gas ...
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1 vote

How to estimate and compare operating costs of gas vs electric furnace?

Heat pumps usually supply air conditioning too so they would be part of the equation. The fact that your neighbors all have converted to a gas furnace should tell you something, maybe that gas is the ...
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1 vote
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Where do I connect my common wire (C wire) for smart thermostat?

You need to be tapping C from your air handler The Ecobee 3 is like many other smart thermostats in that in a two-transformer system, it assumes that the main 24VAC transformer in the system is at the ...
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0 votes

Where do I connect my common wire (C wire) for smart thermostat?

If you had an mercury thermostat it would have a wire running to it and a return it simply completes a circuit. The C wire is to supply 24 volts so your electronics in the new thermostat are able to ...
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Where do I connect my common wire (C wire) for smart thermostat?

The photos of the diagrams are not big enough to zoom into, but typically the C wire is blue. The C wire provides 24V so check your diagram for a terminal labeled as that amount of voltage. Confirm ...
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5 votes

Junction box for furnace fuse reads hot with NCVT, but the furnace operates normally. Is this dangerous or incorrect?

It's very common for people to wire metal boxes like plastic ones, ignoring the box altogether and wiring grounds "thru" or not at all. In that case, the metal box would not be grounded, ...
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-1 votes

Can a blown furnace transformer cause "hot spots" on the furnace circuit board?

The transformer did not blew up, it had a short and created an ARC. But saying transformer blew up means it suffered a catastrophic event. Arc is uncontrolled amount of current that overload the ...
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2 votes
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Junction box for furnace fuse reads hot with NCVT, but the furnace operates normally. Is this dangerous or incorrect?

The NCVT could detect a hot wire even up to 1 inch far away. So, to be sure use Multimeter, since NCVT could be misleading. Here is a simple test/proof. Just wave it in front of wall socket without ...
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2 votes

Help with installing Google Nest thermostat

Thermostat wire colors are not standardized. Any installer can use any color they want for any wire. However, it's obvious that the designers of furnaces were talking to the makers of thermostat ...
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