External T-Stat for Monitor K-1 heater?

[HayZee518]

but a thermostat will not work with a monitor heater. the thermostat has a bi-metallic element that expands or contracts according to temperature and in turn switches on or off a burner. the thermistor in its use with the monitor changes its resistance according to temperature. this varying resistance is used in the motherboard's electronics to operate the heater. I tried shorting the thermistor connector on my old M41 and the unit went into overheat lockout. an open thermistor defaults at 42 degrees and the unit won't shut off.

[dave100]

external thermostat

You actually could use a normal bi-metalic thermostat to switch in a 20K resistor across the existing thermister and by trimming that value a bit you could then externally switch between two temperature settings. You'd have to experiment with values a bit to make it run the way you want, but it's certainly doable. The readout will tell you the temperature the Monitor THINKS the room is at and you'd have to compare that value with the actual current temperature and work from there to achieve the desired effect.

[hawkins111]

room sensor thoughts

All these energy efficient thermostats are great if you have a boiler or some other heating source that can heat different rooms to different temperatures. They do not work on a Monitor or Toyostove. Both of those heaters are really space heaters. They heat one space up to the temperature you choose on the Indicator circuit board. If you move the room sensor to a different room the stove tries to heat that space up to whatever temp you choose. When you do that the room the stove is in heats up to a temperature that is much higher than the other room and becomes uncomfortably hot. The only way to heat a room that is removed from the room the Monitor heater is in is to have a room to room fan located high on the wall. That fan can be controlled by a line voltage thermostat. That system is completely separate from the Monitor room sensor. The Monitor heats up the room it is in to something comfortable and you just rob some of the heat trapped up high in the ceiling. As others have said, those thermostats do not work with Monitor room sensors.

Tom

[ny_upstate48]

I have a monitor 441. In the manual mode the heater will bring it up to temperature and once that temperature is reached. The burner goes to low mode and stays running. It no longer goes past the set temperature and then shuts the burner off. It just stays running. What would be the cause of this?

[HayZee518]

what causes this - is the heater is undersized for the room temperature. the heater switches into low to maintain the heat in the room and keeps on running because the thermister never detects an increase in room temperature. try moving the thermister around in the room, i.e. different heights so it'll detect an increase in room temperature. I know my 2400 does just that. It idles at 74 degrees in low heat because the temperature never increases. your room may have odd circulation currents or lots of cold air leaks.

[ny_upstate48]

I tried moving the thermoistor up higher the temp did go to two degrees higher then it was set at. The Burner switched to low and then kept running. It never did shut off. So I then held the wire above and in front of the monitor and it would then shut the burner off. I read your post of extending the wire using phone wire. I most likely try that but I am very reluctant to cut the plug off it. Is there any place I can buy the male and female plug so I can make an extention wire without cutting?

[HayZee518]

you can look into MOUSER ELECTRONICS in Texas or ALLIED RADIO for a MOLEX plug and receptacle.

[hawkins111]

room sensor

Lots of questions. What is the Set Temp? How cold is it outside? Do you have the Economy Plus feature ON? Is the room sensor near a window, over a vent, too low on the wall? What model stove do you have and how big is the room?



Don’t cut the sensor wire. Read post #18 to get a better idea what the sensor does. You do realize the sensor shuts the stove off normally at 4 degrees over the set temp, and 12 degrees over when the Economy Plus is used.

Stay warm,

Tom

[ny_upstate48]

The temp is set a 62. Today is was not cold out it is about 20 degrees. I dont use the economy plus button. ( I dont understand the sense of that button) It gets to temp it is set at and then the burner kicks to low and then continues to run at low. It does sit below a window. I have no intention on cutting the wire. I would like to get the connectors to try to make an extension for the sensor. I hope it is just a sensor issue not a board issue.

[hawkins111]

set temp

How big is your room and house? What model stove do you have? Is the circulating fan and screen spotlessly clean?? Do you have any other source of heat?


I don't think there is anything wrong with your stove. I do think the stove just can't get the room any warmer than 62, with thermistor at what ever level you have it.



Tom



Tom