burner won't shut down at or near hi lim setting.....

Weezbo

the high limit aquastat that you have is a dial operation come to think of it...

it is designed not to have a low limit ...so ,...Turn it off, turn the dial down to 170...it ought to top out around 190...

Nick W

burer won't shut off at or near hi limit setting

I have a 6-7 year old Burnham V 73 oil fired boiler I installed that has served our 1 story, small rancher with 3 basement loops, well, until now. All I did was clean her out with the boiler brush and lower the Honeywell 8148A aquastat's hi limit to 180 from 210 degrees. I had some "experts" say this might creat some oil savings but in investigating further, I am now of the opinion that the higher setting might be best. In any event, the next thing I see is the burner won't shut off, the temp passes the limit, water pressure goes way up to 30+ and copper pipes distant from the boiler are cool. What the hecht happened????!!!! This is bizzarre! Well, I started messing with the stat now and the pressure. As a back up I bought a new aquastat on ebay, tried firing her up and tried different ways to purge air, etc. I finally got hot water to move all thru the big long loop with 3 ups and downs to serve 1/2 of my basement, BUT the burner still did not shut down at or near the 205 degrees I set the NEW stat at. I tried it twice and the guage went to 220 and I feared it was risky, no I got scared to be honest, and flipped her off. To bring down the boiler temp I disconnected a burner wire and ran the circulator pump for a while. Now, here I sit in total mystery as to why she will not shut off. The temp guage may be off slightly and I have not checked it but I felt the pipes in the basement ceiling and one was super hot like never before in my "feel" tests. Typically, you can touch a pipe that has been properly heated here for 1-2 seconds before it burns. Same in my former furnace. This pipe was much hotter. I watched the gauge as the temp and pressure rose. If the hi limit would havecut off timely, the water pressure would have stayed around 20 which is about right. But, it dd not and I flipped the service switch. What is going on here? What tests can I do or further exploration? I am baffled! Please help???

heatguy

advice

rick you need to call a pro you are in over your head a run away boiler with circulation problems is a bomb waiting to go off call somebody

ed wallace

problems

you have a time bomb on your hands please stop know and call a pro

Derheatmeister

Yes i also think that you should call a pro. And buying a very important part like this on ebay can be bad too. I've seen this once before when someone change the Aquastat that they acquired on ebay and it was a "runaway boiler" They called me, i put on a new Aquastat and everything worked fine!!! the customer send the Aquastat back (the manu. date was very old ) Maybe you got this one now!! having fun with it???

Weezbo

It Is Cold out...

turn it off.

then look real closely at the triaquastat,....you will see a dial that says LO and one that says HI and one that says Diff.

turn the LO one down to 140..

THEN turn the one that says HI down to 167...

turn it back on..


when it comes up to heat...

pay close attention when it shuts off.

if it continues to go beyond 220 you're in need of a telephone. even if it settles down to 185 190 you listen to what these other guys are saying...

it is ok to let the circ roll on an extension cord till the rooms come up to temp if the relay is burnt out to the circ.

*~/:)

burnerman_2

my thought

if you installed a new aqustat did you make sure the probe was not broken or that it was completly in the well this will change the temp had this happen on a new install seen temp raising what the heck ckecked sure enough the probe was only half way in my thought royboy