My daughter's apartment has a very simple heater. As shown in the pictures below, it is an heater-coil unit with only a fan control. There is no temperature control or thermostatic feedback. So, for example, the heater cannot be left running unattended for extended periods of time, like overnight.

I'm wondering if there are any solutions that can attach to a heater like this to provide automated thermostatic control. Since this is in a rental unit, replacing the heater is the last thing she would want to do. In my mind, a simple mechanical attachment to the fan control would be ideal. Has anyone seen a solution to a problem like this?

I found a link to the product line for this heater (SeasonMaker ThinLine Fan-Coil Units), and it shows that there are thermostats available for some configurations. I can't decipher the catalog to understand how this might work with this particular unit, or if it can work at all.

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    Are you quite sure that's an electric heater? It looks more like a "fan coil unit" that's typically supplied with hot water, and the electric bit is just for the fan. – Ecnerwal Jan 4 '18 at 21:26
  • Upon closer examination, it actually states that it's a fan-coil unit, though that has been partially defaced. Or has a bobby-pin lying on top of it, I guess. There's basically no risk to leaving such a unit running all the time. – Ecnerwal Jan 4 '18 at 21:38
  • Yes, I found a catalog and understand now that it is a fan-coil unit. I included the link to that catalog. – Jim Jan 4 '18 at 21:45

NOT an electric heater - a hot-water heater with an electric fan, connected to a central source of hot water (which might be under control of a thermostat not local to the Fan Coil Unit.) It is not inherently hazardous to leave such a unit turned on 24 hours a day.

Would be a fairly simple/inexpensive "robotics" project to have a temperature sensor and a servo or stepper motor that connected to the dial, which would not require any "landlord irritating" attempts to modify the internals of the heat unit. Landlords are not generally thrilled with tenants who modify things the landlord owns, so don't go there.

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    I was thinking along the same lines. But before I start inventing, I was hoping a solution is already available. There might be some interest in this by others in her building and city :) – Jim Jan 4 '18 at 21:51

They make external thermostats for that very unit. Tell the super you'd like one, ask them how much they'd want to install it, and if you can do a deal, you can do a deal.

But you understand how that unit works? It does not make heat nor cold. Service water, supplied by the building's plant/ boiler works, arrives at your heater at 45-140F (depending on whether it is configured for heating or cooling). Service water is circulated through your heater, and returned to be re-heated or re-chilled. The upshot is that nothing in it operates at a hazardous temperature.


I think Ecnerwal in is right. Especially because you are in a big city ape. Most of those buildings have a large single boiler in the basement and circulate a certain temperature of water throughout the building constantly; as the outdoor temperature drops the water temp is raised. If you want heat in your apt you simply turn on the fan the speed you want.

  • Thanks, Paul. I corrected the description to fan-coil unit in an edit to my question. The goal is to have thermostatically controlled heat. Getting heat is the easy part. – Jim Jan 4 '18 at 21:47
  • I guess I don't understand what exactly you are trying to achieve. – Paul Logan Jan 6 '18 at 3:51

Leave the internal fan off. Add external ductwork feeding the air inlet from a thermostatically controlled fan -- which can be a bathroom ultra-quiet blower so you don't have to listen to the thing. The thermostat sensor might be placed elsewhere in the room, for more even temperature control.

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