Wifi Thermostat for 60amp Heater

[cthulu]

I got this bad boy below and it has an integrated thermostat.

https://www.northerntool.com/shop/tools/product_200665041_200665041

My shop is about 100ft away and has wifi that connects back to the house. Tired of walking out there to flip it on and worried I left it on on accident and having the check it.

The unit has a built in dial thermostat which works good but I'd like to do something more sophisticated so I can turn the heat on/off from the house, monitor the temp (and optionally humidity levels) in the garage without having to trudge out there.

What would you guys do? I hear a lot of the wifi devices are kind of crappy, curious if anyone has had good experiences with theirs.

 

[ishiboo]

I have a Nest and a proprietary Bryant Wifi thermostat, both have been flawless. I've had my Nest for quite a few years. Not "kind of crappy" at all.

That heater doesn't have a connection for a remote thermostat. Which means you will need to have a large contactor (relay) with a 24VAC coil and a 24VAC power supply to be able to control it. Something like:

https://www.automationdirect.com/ad...actors_-z-_Overloads/65_to_80_Amp/SC-E4-24VAC

and

https://www.amazon.com/dp/B0007N5LJK/?tag=atomicindus08-20

 

[cthulu]

That heater doesn't have a connection for a remote thermostat. Which means you will need to have a large contactor (relay) with a 24VAC coil and a 24VAC power supply to be able to control it.

Yeah that was the dilemma , the fan stays on after the coils turn off. It's a function to prevent the coils from damaging themselves from what I understand.

I understand how to wire the relay and supply for a remote thermostat I'm unsure how to get the fan to continue to kick on after the relay shuts off when triggered by the thermostat. I'll need to look at the wiring diagrams for the heater and figure it out, appreciate the links and the feedback on the nest!

 

[PoorOwner]

fan or green wire out of the thermostat would turn on the fan, it should let the fan to be on after the heating shuts off to cool off to cool down the heat exchanger. At least that's how it worked in the furnace and thermostat in my house.

So if you are able to splice the original fan signal with the thermostat (maybe using a relay to control continuity to the original fan wire), or maybe it has a 24VAC control as well, you should be good to go after some testing.

 

[Bert_]

I looked up a diagram for that heater. It already has a contactor in it but it uses a 240v coil. Your options are either use a 24v ice cube relay to control the existing contactor or replace the contactor with a 24v unit. Either option will require a 24v transformer capable running the contactor or relay.

 

[cthulu]

What do you guys think of the below?

I think I got it, I set the thermostat on the heater itself to say 70F then I hookup the relay and the transformer for the wifi thermostat so I can turn it on and off from the house and set the wifi thermostat to say 80f. It will keep power to the unit on and the unit will continue to self regulate and use fan cool downs as its internal thermostat is limited to 70f.

I think that will work!

 

[Stuff]

The documentation doesn't make sense to me. Does the fan have a separate sensor to turn it off when things cool down? Or does it run anytime the switch is on?

 

[PoorOwner]

What do you guys think of the below?

I think I got it, I set the thermostat on the heater itself to say 70F then I hookup the relay and the transformer for the wifi thermostat so I can turn it on and off from the house and set the wifi thermostat to say 80f. It will keep power to the unit on and the unit will continue to self regulate and use fan cool downs as its internal thermostat is limited to 70f.

I think that will work!

No if you set the the heater to 70 then it will just be at 70.. you usually set the heater for max.

 

[old__man]

What do you guys think of the below?

I think I got it, I set the thermostat on the heater itself to say 70F then I hookup the relay and the transformer for the wifi thermostat so I can turn it on and off from the house and set the wifi thermostat to say 80f. It will keep power to the unit on and the unit will continue to self regulate and use fan cool downs as its internal thermostat is limited to 70f.

I think that will work!

I just went through something very similar just with no relay. On my heater I just bypassed/replaced the heater's thermostat with my own wall mounted thermostat.

If you wanted a relay in there you would just bypass/replace the factory thermostat with the relay. Have relay controlled with the thermostat of your choice.

This way your fan and fan controller are unaffected and you have total control of the heater.

 

[u3b3rg33k]

My favorite wifi/web enabled thermostat is the honeywell YTHX9421R5085WW (prestige). I built a relay board with a contactor to control an outlet, but you could have it run a heater, too.

 

[ToecuttersZ1R]

The way I would go about installing a remote tstat for this heater is as follows.

1-Get a fan control center that will handle the amp draw for the fan and a 4x4 electrical box.
2-Run a 115 volts to the 4x4 box to power the transformer.
3-Run 2 wires from the 4x4 box to the heater. Connect the wires in the 4x4 box to the normally open terminals on the relay. Connect the wires at the heater to the L1 leg after the heater connections and before the fan switch (page 5 in the manual). If the wires are connected before the heaters that amperage will go thru the fan center and that's a big no, no. Also the wiring and connectors should be of the heat rated type.
4-Run 4 conductor tstat wire from the smart thermostat to the fan center. Some smart tstats need a common wire from the transformer.
5- Leave the fan switch on and set thermostat on the heater 5 to 10 degrees higher than the smart tstat. This way if the fan center relay got stuck in the closed position the heater should cycle on and. The fan will stay online.

https://www.grainger.com/product/WHITE-RODGERS-Center-3TZ56?opr=APPD&pbi=3TZ56&analytics=altItems


https://contal.mecanair.net/transfert_fichiers/F274073.pdf

 

[The_Auto_Tech]

The way I would go about installing a remote tstat for this heater is as follows.

1-Get a fan control center that will handle the amp draw for the fan and a 4x4 electrical box.
2-Run a 115 volts to the 4x4 box to power the transformer.
3-Run 2 wires from the 4x4 box to the heater. Connect the wires in the 4x4 box to the normally open terminals on the relay. Connect the wires at the heater to the L1 leg after the heater connections and before the fan switch (page 5 in the manual). If the wires are connected before the heaters that amperage will go thru the fan center and that's a big no, no. Also the wiring and connectors should be of the heat rated type.
4-Run 4 conductor tstat wire from the smart thermostat to the fan center. Some smart tstats need a common wire from the transformer.
5- Leave the fan switch on and set thermostat on the heater 5 to 10 degrees higher than the smart tstat. This way if the fan center relay got stuck in the closed position the heater should cycle on and. The fan will stay online.

https://www.grainger.com/product/WHITE-RODGERS-Center-3TZ56?opr=APPD&pbi=3TZ56&analytics=altItems


https://contal.mecanair.net/transfert_fichiers/F274073.pdf

Could you use a similar setup for the heaters that simply use the dial type thermostats? I'm guessing you could just set the dial to max and then using the thermostat to turn the power on and off?

I'm just trying to make sense of the wiring setup you're talking about. Currently I have 8/3 run from a 40A breaker to a 50A range receptacle. From there I have a 50A range cord wired to the heater. I believe the max amp rating for the heater is 31.3. From what I've seen most of the transformers aren't rated for more than 23 amps...

 

[The_Auto_Tech]

Also, from what I'm understanding the issue with doing this is that the smart thermostat will quickly drain the batteries as it won't be properly powered?

 

[ToecuttersZ1R]

Could you use a similar setup for the heaters that simply use the dial type thermostats? I'm guessing you could just set the dial to max and then using the thermostat to turn the power on and off?

I'm just trying to make sense of the wiring setup you're talking about. Currently I have 8/3 run from a 40A breaker to a 50A range receptacle. From there I have a 50A range cord wired to the heater. I believe the max amp rating for the heater is 31.3. From what I've seen most of the transformers aren't rated for more than 23 amps...

Yes you could use a dial or digital tstat. The OP wants to connect a smart tstat to have the ability to operate the heater from inside of his house.

The transformer for the setup I described is for the control circuit. Its 115 volt primary to a 24 volt secondary. It will power the relay and tstat only.

 

[The_Auto_Tech]

Yes you could use a dial or digital tstat. The OP wants to connect a smart tstat to have the ability to operate the heater from inside of his house.

The transformer for the setup I described is for the control circuit. Its 115 volt primary to a 24 volt secondary. It will power the relay and tstat only.

I meant to say can it be used with a heater that has the normal dial type thermostat, not the digital ones. The one you were talking about originally has a digital display, mine just has the dial you adjust for the temp.

Is there any chance you can draw out a diagram and take a picture of it so I can help to understand how you would wire it up?

 

[ToecuttersZ1R]

Here you go Auto Tech.

View attachment GF_heater.pdf

 

[old__man]

Would it not make more sense to replace the factory t-stat with the relay in your diagram?

 

[ToecuttersZ1R]

Would it not make more sense to replace the factory t-stat with the relay in your diagram?

You could wire it in place of the factory tstat. But the fan will run all the time. I prefer the fan cycle with the heat.

 

[The_Auto_Tech]

Thanks for that. Curious how you would apply your wiring diagram to this heater as this is the one I have.

https://hw.menardc.com/main/items/media/HEIND001/Install_Instruct/eh4604b.pdf

I'm assuming that 115V circuit can be powered by anything i.e. outlet/light fixture/whatever? I'm confused because above you said run 2 wires from the 4x4 box with the transformer directly to the heater but your diagram doesn't show any wires going from the transformer to the heater, just from the smart thermostat to the heater.

 

[dogdog]

You could wire it in place of the factory tstat. But the fan will run all the time. I prefer the fan cycle with the heat.

would make more sense if you just use two relays one for the Fan and one for the factory T-stat. set your wifi thermostat to Furnance.... ?

Use the wire R W C and G.

 

[Bert_]

Everybody is overthinking the fan problem. As it is wired now the fan is turned on by a switch that senses heat from the coil, it's labeled "fan switch" in this diagram and is automatic. No reason to change that. This is the diagram for the OP'S heater that I pulled off northern tool.

Either replace the contactor with one that has a 24v coil or use a relay to control the current contactor. The second option will let you use a smaller transformer. I would use a 240v to 24v transformer rather than a 120v transformer. That way you can connect it to the input power to the heater instead of having to get power from another circuit.

 

[ToecuttersZ1R]

would make more sense if you just use two relays one for the Fan and one for the factory T-stat. set your wifi thermostat to Furnance.... ?

Use the wire R W C and G.

Yes you could use 2 relays, I would not wire it that way. But as far as using the G terminal on the tstat. It is not energized in the heating mode. It gets powered thru the Y terminal or the fan auto/on switch.

 

[ToecuttersZ1R]

Thanks for that. Curious how you would apply your wiring diagram to this heater as this is the one I have.

https://hw.menardc.com/main/items/media/HEIND001/Install_Instruct/eh4604b.pdf

I'm assuming that 115V circuit can be powered by anything i.e. outlet/light fixture/whatever? I'm confused because above you said run 2 wires from the 4x4 box with the transformer directly to the heater but your diagram doesn't show any wires going from the transformer to the heater, just from the smart thermostat to the heater.

For your heater I would connect the N.O. contacts of the relay to the L1 leg between the power light and the tstat. Also, set the heater tstat 5 to 10 degrees above the wall mounted tstat.

Yes you can get the 115 volts from any source that's always on. The fan center mounts onto the 4x4 box which also has the relay and that's were the 2 wires from the heater will get connected.

The diagram is to show you how its wired, not the location of the controls. Take the diagram for your heater for example. They show the contactor's coil (J) in one area and the contacts in another area, yet they are one device.

 

[dogdog]

Yes you could use 2 relays, I would not wire it that way. But as far as using the G terminal on the tstat. It is not energized in the heating mode. It gets powered thru the Y terminal or the fan auto/on switch.

My parent's furnace have the G terminal... the forced hot air furnace when fan is set to auto will turn the furnace fan on... I'll have to check if it gets a 24V when it is on.... when I get there. don't remember this 100%. But the furnace fan runs when heat is on... it has to run...

 

[Stuff]

My parent's furnace have the G terminal... the forced hot air furnace when fan is set to auto will turn the furnace fan on... I'll have to check if it gets a 24V when it is on.... when I get there. don't remember this 100%. But the furnace fan runs when heat is on... it has to run...

A gas central air furnace is a different monster. 24vac is used for the fan controlled manually by the thermostat's G wire. Older furnaces had a separate 120v fan/limit switch that activates the blower when things warm up. Newer systems have a timer that runs the blower after heat kicks on. Neither system goes through the G terminal.

Some thermostats can be set to electric heat which will then activate the G on a heat call along with W.

 

[ToecuttersZ1R]

Stuff

 

[CrankyOldMan]

Not sure if it warrants its own thread, so I'll start in here. There's also a few new products that may be useful, but I'm not sure.

I've got the 7500W version of the one linked in post #19. The manual includes a diagram for a remote line-level thermostat on page 9. It only switches the fan, relay coil and indicator lamp. The motor is 1/10 hp, so there's not much draw on that and the coil can't be more than a few hundred mA at worst. Not sure why they recommend a 28A thermostat for that since the coils aren't directly switched, but they do.

I was considering using one of the newer "baseboard heater" thermostats but the manufacturers are all wishy-washy about using them for "other" applications like an electric forced air heater. Can't seem to get a straight answer about it being feasible, but should work if it's just on/off. One of them uses a triac (like a dimmer switch) to modulate the voltage. That seems like a really bad idea for a contactor.

The most reasonable one I've seen is to use a 24V thermostat and a module that mounts to a conduit knockout for controlling the 240V circuit (Aube seems to be a common brand for those). I hadn't considered the source of the 24V, so I would also need a way to derive that, right?

I've also considered adding an off-delay module for the fan so that it keeps blowing on the coils when they turn off. Is that worth the $100 to add that to a $250 heater?