Thermostat set at 45, shop 60 degrees ??

[andis65]

Ok, need some more help here, I have my radiant heat system fired up and operational. Now that it's run for two days , I notice it seems to be running nonstop. The input temp is. 122 and return 86, however the wall thermostat is set at 45 degrees on the wall about 5 foot high, and a thermometer I have in the shop reads 60 degrees. ??? The fellas at the supply house I got my equipment from told me to use a simple electric heat thermostat 120v to turn the circulator on and off. My missing something ???

 

[HiItsMeJimmy]

I set my radiant thermostat to 57 and my cheapo wall thermostat reads 66. I'm not using a slab sensor which might be the problem.

 

[oldgoaly]

are you setting it and leaving it? or turning it up and down, there is a lag. also the mercury type need to be level, there is anticipator setting to limit over shoot of temps.

 

[rclassic]

I have a $12 electric bi-metal thermostat,its set on 45 ,the shop is around 55 and the floor is 58. I do not have a floor sensor and its average run time is 2 hours 1 or 2 times a day depending on outside temp. IN temp is 100 OUT is 68@ 2gpm.

 

[andis65]

To clarify the thermostat i have is designed for electric baseboard heat. I typed only electric in my original question. They suggested i use it because its 120v and doesnt need additional equipment. I know its possible that its a faulty thermostat but it sounds like other people have this issue? question is, a thermostat is simple.. it should trip the circulating pump off when air temp reaches 45...

 

[andis65]

and another thing, someone asked if i was playing with it, its been set at 45 for three days, i only yesterday turned it down to 42 where it finally tripped off..so i left it there overnight and the temp this morning was 56...

 

[koditten]

Is there a draft contacting that thermostat?

 

[Rockhead261]

Thermostat is your problem. Electric heat has very little residual effect so the thermostat must wait for the actual temperature to be reached. Radiant heat on the other hand has a great deal of residual effect. This is why your space is overheating. You need a thermostat with an adjustable anticipator. It will anticipate the residual heat and shut the system off a little early so that it doesnt overshoot the setpoint.

Sent from my SCH-I545 using Tapatalk

 

[jayoldschool]

Also, if you use one of the old style stats, you can mount it tilted to the right (about 15 degrees). This will allow the actual temp to be lower than the called for temp.

 

[oldgoaly]

you can put a real thermometer nearby and see what the temp is the pull the front cover off of t-stat, on the backside of the temp there is a screwdriver slot for correcting inaccurate settings.

 

[Rookie2]

Either don't look at the numbers and set it to where you are comfortable or like i did i just cycle my boiler and circulators on once or twice a day for 1-2 hours and i'm happy at 55 deg.

 

[larry_g]

Try taking your thermostat off the wall and lay it on the floor. Your going to have to learn what works for your building. With the large heat sink of the floor, and no air movement in the building there is a large disconnect between the heater and the building. Is the 60* degree reading right at the thermostat or some where else? How well is your building sealed and insulated? Your statement

"The fellas at the supply house I got my equipment from told me to use a simple electric heat thermostat 120v to turn the circulator on and off."

leads me to believe that you do not have an engineered system and that is OK but it also leads me to believe that you now have a bit of a learning curve to go through. Play with the system and figure out what you have to do to get it maintain the building at the temp you want.

lg
no neat sig line

 

[tdkkart]

Also, if you use one of the old style stats, you can mount it tilted to the right (about 15 degrees). This will allow the actual temp to be lower than the called for temp.

If your thermostat has a mercury switch, it MUST be level or it will not function correctly. The old school round thermostats have a couple pins on the baseplate that you can use a level on to level the 'stat.

 

[jayoldschool]

Mine must be bi-metallic then. Three zones: basement radiant(old manual stat), main floor (forced air over boiler heat, prorammable set back digital), and garage (old manual stat, tilted, allows lower temp than minimum on the stat, and it works perfect).

I'm not the only one that knows this trick:

How to set a thermostat below it's official minimum temperature: if your building thermostat is an older model that does not permit temperatures to be set below 50 or 55 deg .f. it may be possible to "fool" the thermostat by tilting it out of level on the wall, so that a setting of "55 degF" on the thermostat dial is really equivalent to "45 degF". A little experimenting (at a higher temperature) will show you how much to turn the thermostat on the wall to re-set its operating temperature range. See THERMOSTATS.

From:
http://inspectapedia.com/plumbing/Winterize_Heat_On.htm

 

[andis65]

My thermostat is a $20 job with no mercury switch. My thermometer is right next to the thermostat on the wall. I was just out there, it was set at 43 all day with actual air temp beside it at 56. When I went out there the unit was running, so I slowly dialed it back until it tripped off at 40. Plan is to leave it there overnight for a test in the morning of actual temp. I did leave out that I have two ceiling fans in there running slow. So there is air circulation.

 

[jayoldschool]

Are the fans pulling up or pushing down?

 

[andis65]

they are pushing down, they arent reversible unless you wire them different. I have them on their slowest speed just to turn the air a little.

 

[Sureshot]

Where are you?
What is the outside temp?
Is their insulation between the thermostat and wall?

I would forget the numbers on the thermostat unless it is a special low temp model. You are likely outside of the designed range and the accuracy will be poor to non-existent. I marked mine with a sharpie for my own references but I can basically turn it down against the shutoff.

 

[andis65]

Im in upstate NY, its pretty cold here already. I have blown in fiberglass between the walls. so i am insulated. Im seeing a trend here with what people are saying. I just assumed it would be accurate like the one in my house. It doesnt bother me at all to just find a sweet spot and leave it, just wanted to make sure i wasnt leaving something out or missing a step of my build.

 

[jlckmj]

It doesnt bother me at all to just find a sweet spot and leave it,

That is exactly what I do, my line voltage thermostat is almost off (around 45*) and it keeps the room air at 58-60.

jim

 

[luke7734]

Either don't look at the numbers and set it to where you are comfortable or like i did i just cycle my boiler and circulators on once or twice a day for 1-2 hours and i'm happy at 55 deg.

For the sake of not spending more money I agree above.
My system has 2 zones with 2 pumps. I went with the taco control panel and wired in the standard thermostats.. they work just fine. But you've gotta buy the control box.
So, if its working where you've got it.. then leave it.. continue daily fine tuning if need be.. then I'd do like others have said and rotate the dial to match the temp if it's a big deal to you.
Good luck!

 

[hidollartoys]

You will need to factor in the outside temps. You should keep a log of the inside temps, thermo set point and outside temps. This will help you determine where the thermo needs to be set.

 

[Burl]

Forget the fans, its radiant heat.