aquastat

[bjwme]

hey guys i have a question about my aquastat. i have a new yorker wc-90 and I have a honeywell L6006C aquastat strapped on the supply pipe coming out of the top of my boiler that controls my draft fan. I came home today and found my basement warmer than normal. when i looked at the boiler the water temp was 205 degrees and by basement zone (dump zone) was running and so was my draft fan even though it is set to turn off at 190. After looking things over I had to turn the aquastat down to 155 to get it to shut off the draft fan. I checked all the connections on the aquastat, took it off the pipe and made sure everything was in good shape and when i put it back together I still have it set at 155 for the high limit but my water temp is 190. Is there something simple that could be wrong or is it toast. I mean it still works but I have to just watch it and make sure I dont overheat anything. What do you guys think?
Thanks for the help

Bryan

 

[RJP Electric]

I use 2 of these strap-on aquastats and you are correct hey are far from being accurate I have noticed also. I have one to turn off my main pump when my boiler gets to 165º, the aquastat is set at 143º to accomplish this. Be sure it is tight against the pipe and your adjustable differential setting is set at the lowest setting too.

 

[WoodNotOil]

Is this a new setup or did it work correctly in the past? Strap-ons do have the tendency to read low (meaning water temp in pipe is actually higher than it is detecting). Remember it is judging temp by the outside of the pipe, not the actual water temp inside the pipe. Try setting it a little lower and see if the boiler comes down with it. Also there is a differential setting on those aquastats. Make sure it is set to 5* and 20*. That could explain it as well.

 

[bjwme]

it has worked good since october (shutting the fan off when the boiler hits 190) but this is just recently that I have had to turn it down to 160 to get the fan to shut off when the actual temp is 190. I wonder if a power surge or something could have got it.

 

[atlarge54]

it has worked good since october (shutting the fan off when the boiler hits 190) but this is just recently that I have had to turn it down to 160 to get the fan to shut off when the actual temp is 190. I wonder if a power surge or something could have got it.

I had some aquastat problems recently when the capillary tube on the remote bulb was routed near a heat source. Can you see the capillary tube on your strap on, maybe it's touching the pipe? I'm not familiar with strap ons, can you insulate and or shield the sensing unit?

 

[Fred61]

Any corrosion between the mating surfaces of the pipe and the sensor?

 

[LeonMSPT]

Is there a reason you're not using the right hand sensor well on the front of the boiler for the fan control? It's how New Yorker specifies in the manual, and mine is set up that way and seems to be working fine.

Strap ons are "okay", but they're not dead on... and the worst thing is the temperature shift... it'll be slower to detect a change than the one in the well.

hey guys i have a question about my aquastat. i have a new yorker wc-90 and I have a honeywell L6006C aquastat strapped on the supply pipe coming out of the top of my boiler that controls my draft fan. I came home today and found my basement warmer than normal. when i looked at the boiler the water temp was 205 degrees and by basement zone (dump zone) was running and so was my draft fan even though it is set to turn off at 190. After looking things over I had to turn the aquastat down to 155 to get it to shut off the draft fan. I checked all the connections on the aquastat, took it off the pipe and made sure everything was in good shape and when i put it back together I still have it set at 155 for the high limit but my water temp is 190. Is there something simple that could be wrong or is it toast. I mean it still works but I have to just watch it and make sure I dont overheat anything. What do you guys think?
Thanks for the help

Bryan

 

[bjwme]

the right hand sensor is running my circulator only and i have the strap on aquastat running the fan. that is the way my plumber sets them up so you can adjust the fan and circulator independtly. it has worked great since october it is just last week that i noticed it wasnt shutting the fan down when it hit 190* now that i have turned it down it works just like it used to except that the aquastat high limit is set to 155*