Furnace check-up being done, need your advice:

[Zeze]

I have two furnaces in my house delivered via central air. Both units are 2007.

The check-up is all fine except he said the capacitor is rated at 7 volts, but my units are clocking in at 5.8 and 6.5. That exceeds the 7% threshold and it could have the motor give out.

$314 each, $500 if done today.

Is he yanking my chain? I know nothing. I know they're getting old so we'll replace them soon enough. Not sure if this $500 is worth it at all.

 

[sdifox]

LoL no. Look up the part number of the starter caps and replace them yourself. Also, never do business with that company ever again.

Amazon.com : furnace capacitor

Literally cheaper for you to fly me down and replace them for you...

Plenty of YouTube videos on how to do that.

Do remember to turn off power to furnace and touch a screw driver to both terminals of the capacitor to drain it first.

What’s a Furnace Capacitor and Why Do They Fail?

What’s a furnace capacitor? In this article, we break down furnace capacitors, why they fail, how they work, and how to maintain them.

indoortemp.com

 

[snoopy7548]

Two furnaces? How big is your house?

 

[sdifox]

Two furnaces? How big is your house?

Dual zone probably

 

[Red Squirrel]

That's a steep price for a capacitor swap, yikes! I would expect a genuine one specific to that furnace to be maybe like $60 at most. You could try a generic one just make sure the characteristics match as it might matter.

7v is low for a start capacitor though, I would expect those to see full line voltage so it should be rated much higher like 300v.

 

[sdifox]

That's a steep price for a capacitor swap, yikes! I would expect a genuine one specific to that furnace to be maybe like $60 at most. You could try a generic one just make sure the characteristics match as it might matter.

7v is low for a start capacitor though, I would expect those to see full line voltage so it should be rated much higher like 300v.

Probably just a run cap for the motor and not the compressor.

 

[Zeze]

Probably just a run cap for the motor and not the compressor.

Yup motor.

 

[Charmonium]

From 2007 till now, there have probably been substantial improvements in efficiency so it might even be worth replacing both units unless you're serious considering a heat pump using ground water.

As to the motor, the main thing I would do is check to see if the ones you have are brushless. If not, ditch them both.

 

[Red Squirrel]

Probably just a run cap for the motor and not the compressor.

Even that runs at 120v though. I guess the start coil maybe runs lower?

 

[sdifox]

Even that runs at 120v though. I guess the start coil maybe runs lower?

No it's just to mitigate voltage sags. The voltage depends.

 

[WilliamM2]

It's a run capacitor, not a start capacitor, those are sometimes on outside condensers for the compressor, never the fan.

If you buy from Amazon, spend a couple extra bucks on american made (B.M.I., Amrad, Titan HD). They last longer.

 

[WilliamM2]

From 2007 till now, there have probably been substantial improvements in efficiency so it might even be worth replacing both units unless you're serious considering a heat pump using ground water.

As to the motor, the main thing I would do is check to see if the ones you have are brushless. If not, ditch them both.

Have you priced HVAC systems lately? He's probably looking at at least 25K to replace both. He'd be lucky to save $20 a month if they are 80% efficient. A 2007 96% furnace it just as efficient a 2023 96%, and built a lot better, Newer models also require ECM fan motors as well, minimum $1500 to replace. An old motor? More like $150. and I'm just talking parts.

 

[PowerEngineer]

I suspect that the OP has misstated the units for those capacitor measurements. Should be micro-farads (uF) rather than volts. Both starting and running capacitors should have voltage ratings of 350 VAC or higher. These HVAC capacitors are electrolytic and their capacative values decline over time. Too low a value remaining on your start capacitor and the motor will not start. Too low a value on your run capacitor and your motor will run with less torque. Your furnace tech is telling you that your run capacitors are getting old, as are your start capacitors in all likelihood (both are often combined into one part). He may not be pulling your chain, but at $500 a piece he is certainly looking to drain your wallet.

 

[WilliamM2]

I suspect that the OP has misstated the units for those capacitor measurements. Should be micro-farads (uF) rather than volts. Both starting and running capacitors should have voltage ratings of 350 VAC or higher. These HVAC capacitors are electrolytic and their capacative values decline over time. Too low a value remaining on your start capacitor and the motor will not start. Too low a value on your run capacitor and your motor will run with less torque. Your furnace tech is telling you that your run capacitors are getting old, as are your start capacitors in all likelihood (both are often combined into one part). He may not be pulling your chain, but at $500 a piece he is certainly looking to drain your wallet.

They are not electrlytic, but you are right, they weaken over time. And start and run capacitors are seperate. Start capacitors are only in the circuit for milliseconds. And they are only for compressors, or other large motors (like pump motors).

I'm guessing they are 7.5 uf, I've never seen a 7uf. He should look at the old caps, and make sure he matches them. Run caps are rated fpr 370 or 370/440 volts I go with 440, but on an indoor blower motor, either will work.

Round:

Amazon.com

Oval:

Amazon.com

Amazon.com

 

[dave_the_nerd]

Whatever the specs are, a capacitor is silly-easy to replace yourself. That said, the price seems steep but not crazy-steep? Like, HVAC repair is expensive and it's the "rush" time of year for furnaces.

That said, paying something the usual $100 to inspect and clean the furnaces is probably not a terrible idea.

I turned mine on the other day for the first time this fall. Glad I checked - the replacement draft inducer motor comes tomorrow. Also an easy swap, but it stalled/jammed/squealed so hard it scared the dog. (He pooped and ran away.)

 

[WilliamM2]

Whatever the specs are, a capacitor is silly-easy to replace yourself. That said, the price seems steep but not crazy-steep? Like, HVAC repair is expensive and it's the "rush" time of year for furnaces.

That said, paying something the usual $100 to inspect and clean the furnaces is probably not a terrible idea.

I turned mine on the other day for the first time this fall. Glad I checked - the replacement draft inducer motor comes tomorrow. Also an easy swap, but it stalled/jammed/squealed so hard it scared the dog. (He pooped and ran away.)

$500 to replace two caps is ridiculous. Most HVAC companies use the cheapest $10 chinese caps, and then mark them up to $50 each. I can understand that, overhead and all.

But charging ANY labor, when he's already there being paid for the "tune up", and has already removed the caps to measure cpacitance is a scam. It's jus as much labor to put the bad ones back in, and he didn't charge for that!

 

[Zeze]

Have you priced HVAC systems lately? He's probably looking at at least 25K to replace both. He'd be lucky to save $20 a month if they are 80% efficient. A 2007 96% furnace it just as efficient a 2023 96%, and built a lot better, Newer models also require ECM fan motors as well, minimum $1500 to replace. An old motor? More like $150. and I'm just talking parts.

That's about right. I'd be SWOONING at a flat $25K to replace both of my units. God... everything is so expensive.

 

[Red Squirrel]

I was watching a video where someone went all out on a ground source heat pump system that also tied in with the water heater and it was like over 100k! It's complete madness how expensive everything is now. Doesn't matter how efficient it is if it takes a huge chunk of your life time to pay for it. That's almost like buying another house, in some areas.

 

[VirtualLarry]

But charging ANY labor, when he's already there being paid for the "tune up", and has already removed the caps to measure cpacitance is a scam. It's jus as much labor to put the bad ones back in, and he didn't charge for that!

Probably charges labor "by the book" like a car mechanic, and not straight hourly. They gotta eat too, you know.

As a former computer tech that didn't always get properly paid for my labor, requests like this irk me.

 

[Hans Gruber]

Probably charges labor "by the book" like a car mechanic, and not straight hourly. They gotta eat too, you know.

As a former computer tech that didn't always get properly paid for my labor, requests like this irk me.

So if a motherboard costs $150 and they bill you $600 plus labor. Where does it stop? A dual run capacitor for a heat pump is $10. If they charge you $150 for the capacitor and the cost for the part and labor is $500. When do you get irked enough to learn the trade and do it yourself?

 

[dave_the_nerd]

$500 to replace two caps is ridiculous. Most HVAC companies use the cheapest $10 chinese caps, and then mark them up to $50 each. I can understand that, overhead and all.

But charging ANY labor, when he's already there being paid for the "tune up", and has already removed the caps to measure cpacitance is a scam. It's jus as much labor to put the bad ones back in, and he didn't charge for that!

Yeah. As with many things, it all comes down to how you write it up, not the actual work being done.

 

[VirtualLarry]

What really got me is, this same friend that never really much paid me for PC work (nor parts either!), refused to look up how to replace a furnace air-handler filter himself ($6 at Home Depot, maybe, for a filter) on YT, so he had to pay the furnace guy for a
"checkup". Granted, there was another thing to fix, but it could have been a causal result of not changing the air filter for 8 months. And yeah, my friend's place is DUSTY.

 

[Hans Gruber]

What really got me is, this same friend that never really much paid me for PC work (nor parts either!), refused to look up how to replace a furnace air-handler filter himself ($6 at Home Depot, maybe, for a filter) on YT, so he had to pay the furnace guy for a
"checkup". Granted, there was another thing to fix, but it could have been a causal result of not changing the air filter for 8 months. And yeah, my friend's place is DUSTY.

I have 20 pleated furnace filters $2 each from Home Depot for ordering a 12 pack. You want a Merv 8 for residential use. More than that and your blower will either struggle or become less efficient which costs more in your power bill. I change them once every 2 months.

Don't get me started on the drain pump replacement for an air conditioner/heat pump. They cost anywhere from $30 for the basic cheap ones to $100 for a fancy pump. To get one from the HVAC company is $700-$800 including install. That is connecting a couple of tubes and a couple of wires if you have a shutoff/failure wired system. If you know what you are doing, it takes 1 minute to swap out. If you are not skilled 5-10 minutes at most for a DIY'er. I have seen some pump setups (youtube) that is just two tubes and a homeowner could do the swap in 30 seconds or less.

 

[dave_the_nerd]

At this point, if I replace my heat exchanger I'll basically have a new furnace in old clothes.

 

[jmagg]

So if a motherboard costs $150 and they bill you $600 plus labor. Where does it stop? A dual run capacitor for a heat pump is $10. If they charge you $150 for the capacitor and the cost for the part and labor is $500. When do you get irked enough to learn the trade and do it yourself?

Appliance repair is another rip. Paid over 600 for 2 mainboards over the course of a 4 years. It happened again. Found the mainboard for 50 bucks and 10 minutes to install it.