Installing Thermostat for Electric Heater

[MilhouseW]

Awhile back I purchased a Markel (TPI) HF5600 series 240V 5000W electric heater for my garage. For the past few years I just had it hanging from a temporary bracket and plugged it into my welder outlet. I'm finally getting around to mounting it on the ceiling and install a wall mounted thermostat. Initially from what I read in the online manual I believed I could just unhook the internal thermostat and connect a standard 24V thermostat. However, after taking another look at the wiring diagram I believe the statement they make about using 24V control is for another model/option.

I would still like to use a 24V thermostat and believe I should be able to use a 120V-24V transformer (I've been looking at a Honeywell AT72D1683/Z)
but I wanted to get a second opinion and any advice from someone who has done this before. I've attached the wiring diagram for the heater below. Thanks for the help!

Edit: I do have an e-mail submitted to TPI, but have not received a response from the technical group yet.

 

[Tim The Tool Man]

I think you would be better off using a line voltage t-stat like the kind used with electric baseboard heat. You can pick up a wall mounted unit for about $20 at any home center.

 

[Stuart in MN]

According to that schematic it does use a line voltage thermostat, so if you want a wall mounted one it has to have the ability to switch 240vac. Can you just keep the internal thermostat in place, or will the heater be installed where the knob is hard to reach?

 

[Rookie2]

are you painting in the garage ? either thermostat arcs as it makes and breaks. 20.8 amps!

 

[MilhouseW]

Thank you for the replies. I had been hoping to not use a line voltage thermostat due to the location the termostat needs to be in, but if that is the case I can consider it. I have not looked at line voltage thermostats before, but would one that controls 120V be sufficient since it's only controlling one leg of the heater? Also, would the thermostat have to be rated for the full amperage of the heater? Unfortunately the heater is mounted 10' above the garage floor, and I would prefer to not have to mount it lower along a wall. I do occasionally paint in there, but not when the heater is going. I didn't realize that about the thermostats though, so thank you for letting me know. One of the reasons I wanted a heater like this was because it had no open flame/spark.

Thanks again!

 

[Tim The Tool Man]

Thank you for the replies. I had been hoping to not use a line voltage thermostat due to the location the termostat needs to be in, but if that is the case I can consider it. I have not looked at line voltage thermostats before, but would one that controls 120V be sufficient since it's only controlling one leg of the heater?

Just use a regular off the shelf 240 volt thermostat. They only break one leg also...

 

[nehog]

Thank you for the replies. I had been hoping to not use a line voltage thermostat due to the location the termostat needs to be in, but if that is the case I can consider it. ...
Thanks again!

You can use a low voltage thermostat, if you wire in both a transformer (24V) and a relay (rated for the amperage of the heater) as the replacement for the existing internal thermostat. Total cost would not be that high, the transformers are very inexpensive, and a contactor (relay) (Grainger has both for under $100... so other suppliers may be cheaper.)

 

[MilhouseW]

You can use a low voltage thermostat, if you wire in both a transformer (24V) and a relay (rated for the amperage of the heater) as the replacement for the existing internal thermostat. Total cost would not be that high, the transformers are very inexpensive, and a contactor (relay) (Grainger has both for under $100... so other suppliers may be cheaper.)

I was thinking/hoping something like this would be possible. After you mentioned that I did a bit more research and found this: transformer relay (model 24A01G-3)

I think this will work well for my setup, and I've been able to find it for ~$65.

 

[nehog]

I was thinking/hoping something like this would be possible. After you mentioned that I did a bit more research and found this: transformer relay (model 24A01G-3)

I think this will work well for my setup, and I've been able to find it for ~$65.

Sounds like you've found a winner there.

 

[RECox286]

Why bother with the extra complications and expense of using a

low voltage T-stat, which puts more stuff in line for malfuntion,

when a $20 single pole or double pole T-stat will be more than

enough to do the job ? You don't even have to mount it in the

wall, just mount it in a utility box in the heater's power cord, and

hang it like an I.V. at the hospital. Well, it's a thought...

Uncle Bob