I beez an electricimicution guy!

[69hurstolds]

I've never claimed to be a wire-biter. I can navigate around some things electrical and understand ohm's law and all that. I've wired my shop from the ground up, and nothing fried, died, or got laid to the side. I probably will never be an apprentice let alone get a license. But I know I just saved a fist full of dollars today.

This morning when we got out of bed, it was kind of hot in the house for some reason. Yeah, it was supposed to be 72 degrees today, but damn, it was hot. I hear the heater running. WTF? It's set on 68. So I go to the T-stat and it's reading 77. Hmmm.

So I check the set point and it's still 68. Ruh-roh Raggy! I attempted to turn off the unit by the off switch on the T-stat (split electric unit with heat pump) and no go. The fan continues to run...and run... hmmmm? The wife says she smells a little funky smell. I said I just farted so it could have been that. She said it was like an electrical smell. I honestly don't have that much sensitivity in my smeller. I never smelled anything.

I go to check the outside unit and the heat pump is not running. Thus there's no call for heat by the T-stat I presume, nor a call for a fan, so why is this blower running and heat coming out of the vents?

So I turn the entire unit off at the breaker panel, and start checking into things. I open the upper panel where the blower and heat strip controls are and then I got a whiff of what she was talking about. I start doing a visual search and found the sequencers and the relay circuit board for the blower. There was a little bit of evidence of some issue with the relay. I went and got my Fluke, and did a bit of ohm checking on the relays. Ah...relay has low volt coming into the NC side, high volts coming into the NO terminal, and the common goes to the speed wire for the fan. I ohm checked the NC and fan and NO and fan and everything was acting as NC. I checked the sequencers for good measure and they were fine. Turns out the fan relay is on a little circuit board that controls the fan and time delays for the fan depending on heat or cooling and even input from the heater strips so the fan is supposed to come on whenever the heat strips turn on.

I call the local HVAC supply place and they didn't have the exact part number I needed on the shelf. But they could order it and usually it would be here in one day, probably get here on Friday, Saturday at the latest due to Thanksgiving tomorrow. $33 out the door. He said that part is usually 60-80 off the HVAC service guy's truck, and add another $300 with service call and labor to install it. All in all about a $400 job. Seems a bit on the high side, but whatever the cost would be, I got a feeling if I could fix this for $33, I'll feel pretty good about that. What's more interesting about it is it's a plug and play ordeal. The wire connections simply unplug from the old relay board and plug them on to the new board. Easy Peasy. If it works.

Luckily, it's only going to be in the 40s at night and in the 60s during the day for the next few days. So I think we'll be ok without the heater until the part gets here.

So even if you're not a highly trained jack of no trade non-wire biter like me, every now and again the blind squirrel finds a nut. Just make sure you have a good volt/ohmmeter and know how to use it.

 

[pontiacgp]

well if you get cold tonite just pull up the covers and throw some heat in there

 

[GP403]

I thought this was going to be about that moron on YouTube who just electrocutes himself as a circus sideshow. Bonus: It wasn't.

 

[ssn696]

I've never claimed to be a wire-biter. I can navigate around some things electrical and understand ohm's law and all that. I probably will never be an apprentice....but I have a feeling if I could fix this for $33, I'll feel pretty good about that. What's more interesting about it is it's a plug and play ordeal. The wire connections simply unplug from the old relay board and plug them on to the new board. Easy Peasy. If it works....every now and again the blind squirrel finds a nut. Just make sure you have a good volt/ohmmeter and know how to use it.

Not bad, from a knuckle-dragging mechanic.

 

[69hurstolds]

Hey, I resemble that remark. 🙂

When the part comes in and I take the 10 minutes to replace it, I'll report back good or bad if my troubleshooting skills worked.

 

[fleming442]

You better hope it works!

 

[airboatgreg]

I keep a capacitor for my HVC and well along with a well box. I am getting an extra set of points to keep on hand also. Easy stuff to change out. Just shut everything off as 240 volts is not forgiving

 

[Tomeal]

Take one of the low voltage wires off the relay. It should open. If not, the contacts could be goulded. If it's a replaceable relay, it should be pretty cheap. If not check for low voltage at the connection, that will tell you if the board is calling for the contactor to close.

 

[69hurstolds]

I thought this was going to be about that moron on YouTube who just electrocutes himself as a circus sideshow. Bonus: It wasn't.

At least not yet. Usually I have to ask about electrical stuff to even have a place to start. I can read schematics for the most part, so that helps. And checking for power on every wire before sticking your hands in there is always a good idea.

 

[69hurstolds]

Take one of the low voltage wires off the relay. It should open. If not, the contacts could be goulded. If it's a replaceable relay, it should be pretty cheap. If not check for low voltage at the connection, that will tell you if the board is calling for the contactor to close.

Thanks for the tip. During troubleshooting, I removed all the wires from the relay with the power off and I got continuity where I should have, and also on the NO circuit (208V from the transformer in) where I shouldn't. Thus, it was calling for fan because the on/off switch got stuck in "ON". This is causing the fan to run continuously. Relay is made into the circuit board for the electronic time delay and is not replaceable except replacing the whole board. It's only about the size of a playing card, though. It's easy peasy changeout. I just need to get it here.

The heat pump comes on when called for, and goes off when it's not. So the outside unit is working normally. The heater strips are on with the fan when in heat mode whether or not the setpoint has been reached (and I'm not really sure they should be). I did not check to see if the T-stat setting was in "off" if the heat strips were on or not. That's why it was way past above the setpoint on heat and auto. Guesstimated that the heater fan and strips ran for approximately 4 hours straight and that's what was heating up the house.