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[oldsamdog]

Hello, last night it was around  2 degrees, tonight it may go below zero.  I had the thermostat set at 186 degrees on the boiler.  The temp blowing out my floor vents was 114 to 120.  That just wasn't quiet enough  to keep my temperature steady inside.  Had a slow decrease in temperature all night with the fan running constantly.  My question is how much higher can I go up on the boiler temperature so I can get my floor vent air up?
Thanks for any comments.

[tulenutn2o]

Sounds like not enough airflow to me. What is diff in water temp in and out of the heat exchanger? Most guys are running in the 180 deg temp range on their boilers.

[yoderheating]

 It depends on what furnace you have. Some (including the Heatmasters I sell) have a high limit switch that shuts the furnace off when they near 200. Running one hot will most likely mean you will need to add water a little more often. I have run mine as high as 192 with no problem.
As far as tulenutn2o comment on air flow he does have a point. Under perfect conditions you should be able to heat a house at much lower temps. The problem is that often you have to work with what you have. A undersized duct/fan system or a poorly insulated home is often the reason hotter temps are needed. The easiest solution is just to run the furnace a little hotter when its cold outside. 

[oldsamdog]

I measured the temperature at the output pipes on the burner using a infrared thermometer.  Was hard to get consistant results but this is what I got.  Output temp to house at 153. Return pipe temp at 148.  My digital thermostat on the furnace says 187.  I'm not sure if  I'm getting accurate temps.  What is the best way to sample your temperature?  I'm using a remote sensor in the ductwork to get the temperature I mentioned in my earlier post.  As far as fan speed I thought about that as well.  I can't find a way to adjust the speed on the fan though.  It is a little coleman furnace.

[m21221]

I measured my temps also.  Right below the pump a read 10 degrees cooler than what the aqua stat said.  I believe part of difference is where the aqua-stat is located which is near the top, obviously heat rises.  There is no way the temperature dropped 10 degree's in 10 inches of pipe.

[tulenutn2o]

In another thread, Shawbran had ran into a bad controller also. Is there a way you could get a reading at the vent, as in actually touch water with a thermometer?

[oldsamdog]

I think checking the actual water temperature is a good idea.  Getting a actual water temperature reading wouldn't be easy without a long probe of some sorts.   I haven't dug back through the insulation to find where the probe goes in at.  It might be easier for me to stick one in the overflow pipe that sticks out the side.  I have a meat probe but don't think it is long enough though.  I'm new to this.  Only had the furnace up and running around three weeks.   I still have the propane on standby where I just through a switch to go back to it in case it gets too cold. 

[juddspaintballs]

I have a digital thermometer on my supply and return lines right at the boiler.  They are the kind that have the probe wells into the water several inches, so I get accurate readings.  When my house is not calling for heat (but my cast radiator is still running), I get a 0.7 degree drop between supply and return.  When the house is calling for heat, I get roughly a 10 degree drop between supply and return. 

[tulenutn2o]

I have a digital thermometer on my supply and return lines right at the boiler.  They are the kind that have the probe wells into the water several inches, so I get accurate readings.  When my house is not calling for heat (but my cast radiator is still running), I get a 0.7 degree drop between supply and return.  When the house is calling for heat, I get roughly a 10 degree drop between supply and return.

Judd, you got a part # or link to the set up you are using? I wanted to do this in the future also as IR thermometer is so unpredictable. Thanks

[mikenc]

IR thermometer will not give accurate reading on pex pipe. More accurate on steel. I  have one also, reading on pex not exposed to outside  air (in basement)verses steel there is usually 4deg. differance. If you are reading any pipe outside, surface will be  cooler and you will get much lower reading.

Copper pipe or fittings will not give true water temp either.

Could be gpm though coil not able to keep up with demand.  So many variables like have already been mentioned. I would start with getting actual water temp at boiler if possible and go from there.

[rick n kristi]

Some circulator pumps have variable speed/flow, is your pump one of this type? Is it set up on high? Also you mentioned a Coleman furnace, is this in a mobile home?

[oldsamdog]

Yes I have a variable speed pump and it is on high and yes I'm in a mobile.  That I know is part of the problem.  I'm building a ICF house so I know when I get in it there should be a dramatic change.
Last night didn't go well. Was cold in the morning.  The boiler temp got down to 98.  Outside temperature was around 2.  Boiler fan was blowing with a small fire in the back but wouldn't spread around to other wood until I poked it around a bit then it was fine.  The blower is on the front door.  Had my temperature back up to 190 in a little over a hour.  I had filled it with dry wood.   Had to go back to propane to pull the house temperatrue up.  Hope this doesn't happen often.  I'll admit at the moment it happened I regretted buying the furnace. 

[juddspaintballs]

I'll see if I can get a part number tomorrow when I get home.

[Scott7m]

Guys, he's only running a 12x12 heat exchanger, he has the same furnace "coleman" that I do in my double wide.  Temps here have been from -2 to 10 degrees a lot of nights and had zero problems. 

Did you install the furnace yourself?  I remember when you joined or posted about couldn't get a regular size exchanger in your furnace.  That's when I commnted about raising the A coil up and sliding a 16 x 18 directly under it.  If you do this I'd say your problems would be solved and you could drop your furnace back down in temp.  Mine is currently on 158 and doing great. 

[juddspaintballs]

Here's my thermometers:
http://www.weissinstruments.com/digital_vari_angle.html

I have no idea what they cost (though I'm sure they were not cheap!).  I know there are other kinds of well style thermometers that are a regular dial gauge, which would be considerably less.  My father has dial gauges on his.