Category: Uncategorized

Control Board Fails

Control Boards rarely fail, they’re usually misdiagnosed or murdered. When control boards do fail it’s normally an output contact failure caused by age or an electrical surge like lightning or a technician shuffling across carpet before touching it. It’s a

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Causes of High Space Humidity (In no particular order)

There are six primary causes of high space humidity.

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Evaporator Coils Part 4: Troubleshooting

Evaporator Coils Part 3: Direction of Airflow

                      This is an easy one. Remember this rule for DX evaporator coils; Entering air meets leaving refrigerant. Leaving air hits entering refrigerant.

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Refrigerant R410a is Here to Stay

It’s time to accept R-410A as the new R-22 (at least for now) It may be hard to believe, but there are still technicians who think of R-410A as that “new fangled refrigerant with the crazy-high pressures that the ‘Man’

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Control transformers: Watt’s a VA?

It’s 4:50pm. The unit you’re working on has a blown control fuse. The supply houses close in 10 minutes, and it’s 20 minutes away. You scour every shelf, box, and bin in your truck looking for the ever elusive 3amp

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Now and then; Fewer Mustaches, More Stress.

The other day I drove by a crane picking an old rooftop unit from a building’s roof. This kind of stuff always catches my eye, but this one was different; I helped install it in 1987. I remember rigging it

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Condensing Furnace Venting: Part 1 the Termination

For this short run of articles we’re going to start with flue / intake pipe terminations and work our way in to the furnace. The termination location must meet a few criteria to work properly under ALL conditions.

Heat Pump Defrost

There are two types of defrost control. First, there’s the really old electro-mechanical style made up of line-voltage relays, snap-acting temperature sensors and timer motors. We’re not going to talk about these because this stuff is old. Really old. Pittsburgh

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Need To Know Fan Facts

Fan wheels are pretty simple devices. I mean, whats to know about something that’s only moving part is itself. As Yoda would say; “much to know about wheels that blow there is” These seemingly simple single cell creatures (say that

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