2013 - Installing a Fahrenheat FUH54 Electric Garage
The Old Heater
I bought this 4000W Cadet "Hot One" heater shortly after we
finished building our garage in 2001. It was really
undersized for my 24'x28' garage, but once I closed off the
attic space with a new stairwell, it could keep the garage
in the mid 60's while I worked. I only used it a few times
a year when I was working out in the garage, so it lasted
me more than 12 years.
I would blow the dust out of it every now and then with the
shop vac, but did have to take it apart and lubricate the
fan at one point. In recent years the fan bearings were
getting really noisy, so when the thermostat quit working
recently, I decided it was time to buy a new heater.
Preparing the Wiring
After a little research, I chose a new
Fahrenheat FUH54 garage heater
. At 5000 watts, it is
still undersized for my 24' x 28' garage, but it will
provide more heat than my old heater did.
Fahrenheat makes a 7500 watt model also, but I would have
had to run new wiring for that one. The existing wiring
already had 10/3 cable, so the FUH54 was the obvious
choice. I did have to replace the existing breaker with a
new 30amp breaker.
The Cadet heater sat on the floor, and I had a receptacle
it plugged into next to my attic stairs. To keep things
simple, I mounted a new box up near the ceiling and fished
a short piece of 10/3 cable between the old and new boxes.
Garage Wiring Finished
After reading several reviews, I decided to use a clothes
dryer cord to connect the heater. It is affordable, readily
available, and lets me take the heater down easily for
cleaning or maintenance.
To keep the installation tidy, I mounted a dryer receptacle
in the new box up near the ceiling. Then I installed a
heavy duty 30A switch in the old receptacle box near the
Rewiring the Thermostat
While I can reach the thermostat on the heater by standing
on the lower step, I thought a switch on the wall would be
more convenient for turning the heater on and off. I was
originally going to install a line voltage thermostat, but
when I got to the store I saw they had large openings at
the top and bottom. I figured that was just one more thing
to collect dust. Once the thermostat is set, all I really
need to do is turn the heat on and off. The switch works
fine for that, it was half the cost, and I don't have to
worry about dust getting in it.
The FUH54 heater is designed so the fan keeps running after
it is turned off to cool off the heating element. I kept
this feature by turning the unused white wire into a
switched lead for the element. The fan is still wired full
time to keep the original cooling feature.
Rewiring the Heater
Inside the heater, I lifted the thermostat wire that
connected to L1, and connected it to the new switched white
I needed a 3/4" cable clamp to accommodate the dryer cable,
but the FUH54 only has one 3/4" knockout on the left side.
That puts the incoming cable rather close to the terminal
block, but it still works out OK.
The Installed Heater (Temporarily)
I located the ceiling joist, and mounted the heater bracket
to the ceiling with the supplied lag bolts. Then it was
easy to lift the heater up, hook it into the bracket slots,
and secure the bolts.
Finally, I have heat again!
The Cord Issue
Because the FUH54 only had a 3/4" knockout on the left, it
meant the cord had to loop around the back of the heater to
reach the outlet on the right. It worked fine, but visually
it drove me crazy.
Relocating The Power Cord
I decided to move the power cord to the back of the heater,
to one of the knockouts in the center. Unfortunately, that
was only 1/2" and I needed 3/4".
Enlarging the Knockout
Ideally, I would have preferred to use a knockout punch to
make the hole bigger. But I wasn't going to spend $40-60 on
a punch I'm probably never going to use again. A step drill
might have worked, but those were almost as expensive.
Filing and hole saws seemed like too much work, and I was
worried about metal shavings falling into the heater.
Thankfully, I had a metal nibbler that worked great for
enlarging the knockout hole. I have had my nibbler for over
25 years since my days working with electronics, but I see
they are still available today from
Reinstalling the Cord
The nibbler leaves a fairly jagged hole, but once the cable
clamp is mounted you can't tell it's not a factory
Rewiring the New Cord
Once the new cord was installed, I could make all the
connections. Moving the cord to the back middle also
eliminated the crowding around the terminal block.
Remounting the Heater
With the wiring completed, it was a simple matter of
hooking the heater back on the bracket and plugging in the
The shorter cord in the back makes for a much neater
installation. I am just happy to have heat again.