# How do you know if a electric furnace **URL:** \ **Category:** Inspecting HVAC Systems\ **Created:** [February 3, 2009, 1:58am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962 "2009-02-03T01:58:30Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 3, 2009, 1:58am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/1 "2009-02-03T01:58:30Z")
Is operating as intended:D:D:D:D:D:D:D:D:D:D:D:D:shock: AMP meter ![220 Michale Dr PC 2-2-09 051.jpg](https://global.discourse-cdn.com/internachi/original/3X/a/9/a9446a8b3882cc09f192a9d3ea885750feae320f.jpeg) ![220 Michale Dr PC 2-2-09 051.jpg](https://global.discourse-cdn.com/internachi/original/3X/a/9/a9446a8b3882cc09f192a9d3ea885750feae320f.jpeg) ![220 Michale Dr PC 2-2-09 049.jpg](https://global.discourse-cdn.com/internachi/original/3X/1/3/1314f1e49062175e27f39c7b8e8b9819a38e9879.jpeg) ![220 Michale Dr PC 2-2-09 046.jpg](https://global.discourse-cdn.com/internachi/original/3X/7/b/7b84c5a85a49df14910103ecd297d06f929f72aa.jpeg) ---
**Author:** ![swaskewicz](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/swaskewicz/32/1400_2.png) [@swaskewicz](https://forum.nachi.org/u/swaskewicz)\ **Post date:** [February 3, 2009, 2:03am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/2 "2009-02-03T02:03:05Z")
Thanks Charley, good to know. Where do you place the clamp-on? or do you even need a clamp-on Amp meter? ---
**Author:** ![bking](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/bking/32/624_2.png) [@bking](https://forum.nachi.org/u/bking)\ **Post date:** [February 3, 2009, 2:03am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/3 "2009-02-03T02:03:54Z")
Why are those two elements at the right disconnected? ---
**Author:** ![Marc\_D.Shunk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/marc_d.shunk/32/958_2.png) [@Marc\_D.Shunk](https://forum.nachi.org/u/Marc_D.Shunk)\ **Post date:** [February 3, 2009, 2:11am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/4 "2009-02-03T02:11:07Z")
> [@bking](#): > > Why are those two elements at the right disconnected? Some installers favor “sizing” the unit by only connecting as many elements as necessary for the size of the connected ductwork and the space requires. Not really the intended method, but nothing expressly wrong with it either. I’ve seen this method used when a replacement electric furnace was installed and they disconnected as many elements as necessary so as to not overload the existing branch circuit that served the old electric furnace. ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 3, 2009, 2:15am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/5 "2009-02-03T02:15:06Z")
> [@swaskewicz](#): > > Thanks Charley, good to know. > > Where do you place the clamp-on? > > or do you even need a clamp-on Amp meter? Where the Black or Red wire in the pic connect to the element Yes I use a clamp on ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 3, 2009, 2:22am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/6 "2009-02-03T02:22:35Z")
> [@bking](#): > > Why are those two elements at the right disconnected? Two many elements in this furnace installer did not connect them all left one taped off furnace was rated for 13.2- 17.5 KW this was one of the WTF install jobs the worst mess of duct work I think I have ever seen. Just installed within the last month or so the original duct was in the slab and had free standing water they reversed to an up flow and took the low bid. I would be ashamed to even post the pics of the ducts. ---
**Author:** ![jfunderburk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jfunderburk/32/187920_2.png) [@jfunderburk](https://forum.nachi.org/u/jfunderburk)\ **Post date:** [February 3, 2009, 2:47am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/7 "2009-02-03T02:47:14Z")
I just turn it on and measure the heat output at each vent. I’m not an electrician and thank goodness that’s not a job requirement. ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 3, 2009, 3:04am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/8 "2009-02-03T03:04:36Z")
> [@jfunderburk](#): > > I just turn it on and measure the heat output at each vent. I’m not an electrician and thank goodness that’s not a job requirement. Some folks don’t but I guarantee if you inspect many electrical furnaces you will miss burnt out elements. Your call I beat to my own drum:D:D:D ---
**Author:** ![jfunderburk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jfunderburk/32/187920_2.png) [@jfunderburk](https://forum.nachi.org/u/jfunderburk)\ **Post date:** [February 3, 2009, 3:13am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/9 "2009-02-03T03:13:09Z")
You outta charge extra for it. Takes extra time for an unnecessary diagnostic. Do you take the panels off the ones in crawl spaces or 140 degree attics? ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 3, 2009, 3:51am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/10 "2009-02-03T03:51:48Z")
> [@jfunderburk](#): > > You outta charge extra for it. Takes extra time for an \*\*unnecessary \*\*diagnostic. Do you take the panels off the ones in crawl spaces or 140 degree attics? I take to heart the words performing as intended. It is or it isn’t, no I don’t charge extra. Don’t recall ever observing a electric furnace in a crawl or an attic here but if that was the location I would check the elements. Do you take the dead front cover off of electrical panels to me there is no difference. Most home owners will never know if just one element is burnt out they will not notice much temp drop until they get down to about two elements of a four element heater ---
**Author:** ![jfunderburk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jfunderburk/32/187920_2.png) [@jfunderburk](https://forum.nachi.org/u/jfunderburk)\ **Post date:** [February 3, 2009, 3:56am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/11 "2009-02-03T03:56:53Z")
> [@cbottger](#): > > Do you take the dead front cover off of electrical panels to me there is no difference. Removal of electric panel covers is required. I don’t take the covers off an electric furnace or heat pump because I don’t think it’s required. There’s nothing to look at but a bunch of wires and circuits. I’ll keep monitoring this post and perhaps I’ll change my mind on that. But I won’t be doing electrical tests; without a doubt, that is beyond the standards of a home inspection. ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 3, 2009, 4:17am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/12 "2009-02-03T04:17:19Z")
> [@jfunderburk](#): > > Removal of electric panel covers is required. I don’t take the covers off an electric furnace or heat pump because **I don’t think it’s required.** There’s nothing to look at but a bunch of wires and circuits. I’ll keep monitoring this post and perhaps I’ll change my mind on that. But I won’t be doing electrical tests; without a doubt, that is beyond the standards of a home inspection. Well that just goes to show what people know about writing standards when you have a desk jockey or a carpenter writing standards whats to be expected. I have been inspecting electrical furnaces this way long before Oklahoma ever had any standards.😉 ---
**Author:** ![dandersen](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dandersen/32/59398_2.png) [@dandersen](https://forum.nachi.org/u/dandersen)\ **Post date:** [February 3, 2009, 1:45pm UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/13 "2009-02-03T13:45:27Z")
> [@](#): > > I just turn it on and measure the heat output at each vent.I’m not an electrician and thank goodness that’s not a job requirement. You’re not a[FONT=Tahoma][size=2] TAB technician either. How do you measure the heat output? That worthless Delta T thing? [/size][/FONT]A lot of things can happen between the register and the unit[FONT=Tahoma][size=2]. The “real” way of determining Btu output at a register is extremely time-consuming and can be very inaccurate (due to duct deficiency), but it can be done. However you will need about five pieces of test equipment to determine the readings to calculate the BTU gain (a bit more than using an amp meter). [/size][/FONT]For those of you that don’t want to open up the equipment, you can do the same test at the disconnect panel that you are supposed to be opening. If you don’t want to open the service panels of the HVAC equipment to find burn[FONT=Tahoma][size=2]t[/size][/FONT] wires and other visible defects about to cause equipment failure, so be it. For those of you that would like to go to Dave[FONT=Tahoma][size=2]'s[/size][/FONT] school of “you don’t need that test equipment”[FONT=Tahoma][size=2], you can watch the electric meter, turn on the heater and watch the increase in power consumption. Generally these are multi-stage heaters and you will see different steps in power consumption. [/size][/FONT] ---
**Author:** ![jfunderburk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jfunderburk/32/187920_2.png) [@jfunderburk](https://forum.nachi.org/u/jfunderburk)\ **Post date:** [February 3, 2009, 2:46pm UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/14 "2009-02-03T14:46:45Z")
> [@dandersen](#): > > [size=2]You’re not a TAB technician either. How do you measure the heat output? That worthless Delta T thing? I’m indeed not a TAB technician as I don’t even know what that is. ☹ I don’t measure Delta T. I simply use an infrared thermometer at each vent to ensure the vents are functional. For an electric furnace, I should see heat output at 100 degrees F or more. That tells me it works and I move on. I don’t see many electric furnaces. Lots of heat pumps (with heat strips).[/size] ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 4, 2009, 1:51am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/15 "2009-02-04T01:51:31Z")
> [@jfunderburk](#): > > I’m indeed not a TAB technician as I don’t even know what that is. ☹ I don’t measure Delta T. I simply use an infrared thermometer at each vent to ensure the vents are functional. For an electric furnace, I should see heat output at 100 degrees F or more. That tells me it works and I move on. > > I don’t see many electric furnaces. Lots of heat pumps (with heat strips). I lied to you inspected another heat pump today and low and be hold the furnace was in the **attic** when I observed it I had to smile thinking about what I posted last evening and I did pull the cover, 4 screws. Let me ask you this Joe just curious do you pull the blower cover. ---
**Author:** ![jfunderburk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jfunderburk/32/187920_2.png) [@jfunderburk](https://forum.nachi.org/u/jfunderburk)\ **Post date:** [February 4, 2009, 1:58am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/16 "2009-02-04T01:58:59Z")
> [@cbottger](#): > > Let me ask you this Joe just curious do you pull the blower cover. I’ll have to admit on heat pumps and electric furnaces, usually no. What about others? (I know you do Charlie! You probably spin it checking to see if it squeaks.) ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 4, 2009, 2:06am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/17 "2009-02-04T02:06:14Z")
> [@jfunderburk](#): > > I’ll have to admit on heat pumps and electric furnaces, usually no. What about others? (I know you do Charlie! You probably spin it checking to see if it squeaks.) You are getting testy give me a break:D:D:D I use the blower to judge how much lint has accumulated on the A-coil. My hearing is about gone probably could not hear it squeak;-) ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 4, 2009, 2:25am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/18 "2009-02-04T02:25:05Z")
> [@dandersen](#): > > You’re not a[FONT=Tahoma][size=2] TAB technician either. How do you measure the heat output? That worthless Delta T thing? > [/size][/FONT]A lot of things can happen between the register and the unit[FONT=Tahoma][size=2]. > The “real” way of determining Btu output at a register is extremely time-consuming and can be very inaccurate (due to duct deficiency), but it can be done. However you will need about five pieces of test equipment to determine the readings to calculate the BTU gain (a bit more than using an amp meter). > [/size][/FONT]For those of you that don’t want to open up the equipment, you can do the **same test** at the\*\* disconnect\*\* panel that you are supposed to be opening. > If you don’t want to open the service panels of the HVAC equipment to find burn[FONT=Tahoma][size=2]t[/size][/FONT] wires and other visible defects about to cause equipment failure, so be it. > For those of you that would like to go to Dave[FONT=Tahoma][size=2]'s[/size][/FONT] school of “you don’t need that test equipment”[FONT=Tahoma][size=2], you can watch the\*\* electric meter,\*\* turn on the heater and watch the increase in power consumption. Generally these are multi-stage heaters and you will see different steps in power consumption. > [/size][/FONT] David Most Hi’s are not going to know the total amp draw on a furnace or know how many amps each element is suppose to draw so measuring amps at the breaker serves no purpose unless one knows that total. Much easier for me to just measure at the element and that allows me to observe any possible burnt wires at the same time. For those that don’t know electric furnaces are notorious for burning wires, spades loosen up with heat then just simply burn off. ---
**Author:** ![dedwards](https://avatars.discourse-cdn.com/v4/letter/d/e95f7d/32.png) [@dedwards](https://forum.nachi.org/u/dedwards)\ **Post date:** [February 4, 2009, 2:31am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/19 "2009-02-04T02:31:07Z")
This is why I open furnace and heat pump cabinets ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [February 4, 2009, 2:46am UTC](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962/20 "2009-02-04T02:46:20Z")
> [@dedwards](#): > > This is why I open furnace and heat pump cabinets Exactly Master Chief nice pics [Next page](https://forum.nachi.org/t/how-do-you-know-if-a-electric-furnace/35962.md?page=2)