Marley electric heater.

[Ultradog MN]

I have this 220V 4000W electric heater in my shop office that the thermostat is not working correctly. It's all on or all off.
I called Marley and they sent me to a company that can sell me a new thermostat for it >>> For $125 + tax/shipping
That's not gonna happen.
So I'm wondering if there is a way to spray it out the thermostat with electrical contact cleaner and get it working again.
Or wondering what you guys would recommend to fix it. I've blown it out with air but no help.
It has been a great heater for 15 years.

 

[wore out]

Try blowing any dust and debris out of the thermostat with compressed air.

If that doesn't help, is it a DPST thermostat? Can you post a photo while you have the unit opened up to blow it out?

There's quite a few choices on the 'net for t-stats I'm GUESSING ('til we see a photo) are similar for $40 and up.

 

[Geo-TH,In]

HONEYWELL HOME CT33A1009 Economy Non-Programmable Thermostat - Millivolt Heat Only
4.3 out of 5 stars 285
400+ bought in past month
$19.98

<br
Transformer 24V 40VA
Amazon's Choice

$14.39

2 Pole AC Contactor, Generic Heavy Duty 40Amp 24V Coil Air Conditioner Contactor Condenser compressoe
Amazon's
Choice
$11.70

 

[wore out]

George, ''millivolt'' thermostats are for use in thermocouple circuits.

Pick a similar thermostat made for ''low voltage'' (24V.) circuit.

 

[Russ from MN]

Just get a line voltage thermostat like is used for baseboard electric heat, attach a metal box to the side of the heater and wire it through that. Less than $20
https://www.menards.com/main/heating-cooling/thermostats-freeze-alarms/honeywell-white-non-programmable-baseboard-thermostat/ct410b1017e1/p-1531463376605-c-12864.htm?exp=false

 

[Russ from MN]

I might have been too quick with my recommendation, that thermostat might not be rated for 4000 watts.

 

[JMOR]

your link shows 5,800W

 

[Geo-TH,In]

Honeywell Home CT30A1005 Standard Manual Economy
Thermostat - Heat Only

COMPATIBLE WITH: Oil or gas heating systems to
provide low-voltage control of heating equipment.

 

[Russ from MN]

Yes it does, I didn't look at the specs when I found it, I just thought it would work, I was in a hurry to go somewhere! He should be sure to use high temperature wire for hooking it up.

 

[Glenn F.]

I think all electric heater built in thermostats are very inaccurate/unreliable.

Glenn F.

 

[Ultradog MN]

Not much to see.

 

[Ultradog MN]

Thanks.
I had thought about doing something like that but wasn't sure what the parts would cost.
It looks like I would need to bring a neutral in for the little transformer. Am I right?

 

[Jim.ME]

Here is the Marley manual for the 5000w watt heater similar to your heater (possible the current replacement for your 4000 watt one). The manual has a wiring diagram that shows a thermostat like yours and it appears to be line voltage. You might want to study it some before purchasing a thermostat. It appears that heater is in the $500 to $600 range for a replacement.

https://www.marleymep.com/system/files/node/file/field-file//5200-11128-000.pdf

 

[Frankmn]

Buy a line voltage thermostat and wire it into the supply line.

 

[Mule Meat]

That looks more like a Rheostat (better known as a Potentiometer).

 

[Ultradog MN]

Good thing I didn't whip my debit card out just yet.
I blew all the innards of the heater out real well and then reassembled it this morning.
The thermostat is working fine now.
We'll see...

 

[Geo-TH,In]

No need for a neutral, 240 v primary.
24V 40VA Control TransformerPrimary 120, 208, 240V
Secondary 24V Isolation Transformers24V Transformer with Foot Mount for HVAC Furnace
Amazon's
$18.68