I inspected a home today where the general surface temperature of the interior walls were around 16 degrees Celsius. The outdoor temperature was -28 degrees Celsius. But there was a 3 foot by 6 inch section of the wall that registered 22 degrees. Could this be anything else except an overheated wire in the wall? It was right next to a window with nothing else nearby and about 4 feet above a baseboard heater which was not on. I know this needs to be remedied by a qualified professional, but the cause of it baffles me. Any thoughts? :?
What is Celsius?
Okay, for my American friends: The outdoor temperature was -18 degrees F, The wall was 60 degrees F and the warm spot was 72 degrees F. 
I hope this helps.
Possibility of mold.
Being a building/remodeler 30 years I have seen plumbing in exterior walls and not well insulated, and dark siding in sun can add 20 degrees.
What was the orientation of this thing?
How did you measure this temp rise?
Most high temp rise in the wall due to electrical wiring originate at a wall outlet connection.
I often find Hot water lines, heat pump lines, interior wall air leakage from the building heat source(air ducts leaking from below)…
None of which “sounds” like what you are describing.
More info. available?
Do you have images you could post?
Also look for a missing fire block in framing below, letting heat rise
It was a ghost to you do thermo?
This home only has baseboard heat. I did find mold in some of the other rooms along this wall. It had a central air unit outside with makeshift ducting and the plenum in the attic. It was a North wall with light grey colored siding. The house was vacant so the thermostat was turned down to 60 degrees. I read the temperature using my laser thermometer. I do not have an infrared camera. The spot on the wall stopped about 2 feet above the baseboard heater. There were no outlets nearby and no sources of water which makes the possibility of water lines pretty unlikely. The sun was not shining - it was dark outside. There were no visible signs of the temperature spike by looking at the wall although the lino around the heaters was severely burned. There was nothing visible by looking at the wall but I included a picture of the temperature reading and the wrapped up plenum. The basement was insulated with 3/4 inch styrofoam at the interior. The main floor walls were 2 X 4. It was a 70’s home with incomplete vapor barrier in the attic. The poly was about as thick as Saran Wrap. There was evidence of severe water damage at every window along this wall including crumbling gyproc and poor repair work. The windows were basically new. Is there anything else I could mention?
Ok you just said enough.
You were getting a bad reading and why in the heck would you use a infrared therm for that.?
I can see that is not flat paint in the picture and looks like a gloss.
Heat reflecting off of the light.
Cold spot with ice (wall surface below dew and freeze point) reflecting infrared.
Gotta watch out for those reflections.
Did you measure the same spot from different perspecives?
It was not a bad reading. The wall was warm to the touch. That is why I took a reading in the first place. I was feeling the damaged drywall around it and noticed this. All the walls, (interior and exterior) showed up as 60 degrees except this spot. If it was just heat reflecting off the light all the walls would have shown this.
why would you even be checking random places in the walls with a thermometer?
maybe its a metal box full of money or a dead animal… it could be anything and you wont know without opening up the wall.
If your going to be checking temperature differentials on surfaces in buildings, an Ir laser thermometer is not going to work.
Purchase an infrared camera and post the IR pics.
Why was he using an IR thermometer? Because as he said, he felt a wall as being warm in that location.
Is an IR thermometer inappropriate for diagnostics? Long before thermal imaging was available (27 years ago) I began using an IR thermometer, and I still do.
The reflection hypothesis is interesting, but it is not coming from the light source.
No, that is not correct. However…
Number one in the photograph is where the high temperature from the light overhead would appear.
Number two in the photograph is reflection from the digital camera and is where reflected temperature would occur if originating from the inspector and/or his equipment.
Number three is the location of the IR reading, which if you do your geometry would originate from an energy source at the inspectors knees. Possibly another radiant heater behind him.
I have found screws drilled through electrical conductors which did not directly short out the circuit which generated heat identified with a thermal camera.
Seeing as the wall is damaged and needs to be removed for repair anyway, further investigation at that location would be in order.
Ok
I increased contrast and noticed that the wall is bubbled from that thermometer on the wall and straight down to the laser spot.
Wouldn’t it be must easier to simply contact a Canadian iNACHI buddy (close-by) to simply thermally scan this wall?
Time to make a call to the Canadian Super Hero, Mr. Mike. :p:roll: