Aquastat Help

[sgruver78]

OK...so i think i am working out the kinks with my new Outdoor wood furnace except for one thing. I have two Honeywell L4006A stats on my unit. One labeled a Controller and the other a high limit. I have my Controller set at 180 with a diff. of 10 degrees. My problem is that that I can't get the water temp to get above 165 in the OWB. The weird thing is that my blower kicks off when I get to about 160-165 on the temp gauge. Could I have a faulty stat or would it even be possible that my temp gauge on the unit is bad?

What I do know is that after the water passes through the Heat exchanger and into my existing boiler that it only loses like 2-3 degrees from my OWB and my existing boiler temp gauges.

Just can't seem to get the water temp up to that 180 mark. Any suggestions or help would be greatly aprreciated!

 

[Duetech]

Aren't those stats adjustable?

 

[603doug]

I had a similar problem (that I caused playing with the temp) make sure your high limit is set higher than your controller. The high limit on my boiler shuts down the fan and damper to prevent overheating

 

[Eric Johnson]

Your high limit should be sett at around 200. It's really not part of the equation. Your "controller" aquastat should be set at 180 or 190. Presumably it controls the blower. So if the blower is shutting off at 160-165, then it sounds to me like the aquastat is either bad or so far out of whack that it is effectively "bad." Have you tried setting it higher to see what happens? A properly operating high-limit aquastat should shut your blower off at close to the setpoint, and turn it back on at close to whatever the differential dial is set at.

What is controlling your circ pump? Other than the blower shutting down, it could be that your heat load is such that as long as the circ pump is running, the boiler can't get up to temp. And that would be a different problem, such as an undersized boiler or heat loss somewhere in the system.

Does it keep your house warm? Even way down there in balmy southern NY, it was probably close to zero this morning.

 

[sgruver78]

the boiler is rated for 4000 sq feet and my house is only 2400 so i think the boiler is big enough. i have the circ pump running constantly to the heat exchanger. it is def keeping the house warm enough but i thought that is should be running closer to the 180 mark. i think the temp yesterday morning was 17. i was going to go buy a bbq temp gauge with a probe and stick it down my overflow pipe but apparently they don't keep grillin stuff on the shelves at walmart this time of year.

 

[Eric Johnson]

Agreed. Hotter is really better with a wood-fired boiler. If you can keep it at 180 or 190, you'll get less creosote and have a more responsive system. You can buy a regular 1/2" temp gauge from a heating supply store, or perhaps even a big box outlet, for less than $10.