Circulator Question

Sento

I am a homeowner. I have a Utica boiler with Honeywell Triple Aquastat. No hot water tank. I wrote about a week ago about getting too much heat. My oil man ended up putting in a spring-check valve to stop the hot water from circulating. (He said it was probably gravity).
It didn't work. I spent some time in the garage observing and have seen the following:

The circulator pump comes on even when there is no call for heat. (House Temp 70, Thermostat 60).

The burner comes on even when the water Temp is 160 and the
low Aquastat setting is at 120. (Same Thermostat setting).

The system seems to work as it should when I reverse the temperatures on the High and Low settings. (Lo 180 - Hi 160).
(Except that the thermostat doesn't turn the burner on when
I turn it up).

My question is - Is it possible that the installer of the
Aquastat hooked it up backward ? (The same fellow who's been diagnosing the problem). It was a new install fall of last year.

Do you think it might be installed correctly but just busted ?
(In any case I'm pretty sure it's the Aquastat so I'm calling first thing in the morning). Don't you think he
should have diagnosed this already after three visits ?

Do you guys agree with me that it's got to be the Aquastat ?

jim f

what terminals on the aquastat connect to the circulator?? c1 -c2 or zc - zr...also what is the differential set at on the aquastat??
jim f.milford, ct.

Sento

The C1 terminal is hoooked up. I have the differential set at 15 degrees.

Unknown

Ive never seen it happen

But it is possible that the wiring of the aquastat might have been wrong from the manufacturer . There are 5 wires that get pushed into the main body of the aquastat , which is really a dual aquastat with the extra contact on the low side . Im not sure of the color codes though . If you set the high limit at 180 and the low limit at 160 , and there is no call for heat , the circ shouldnt be running and the temp of the boiler will be around 160 to 145 , if the diff is set at 15 . Make sure all the field wiring is right like Jim stated - Circ to C1 and C2 , burner to B1 and B2 , and power to L1 and L2 , and get back to us .

Sento

Wiring

It's a Triple Aquastat L8124-C.
(I only have one zone).

I only see 4 wires as follows.

Red to L1;
White to L2;
Blue to C1;
Black to B1.

Unknown

Gotta track down those wires

And make sure each one goes to the right place . Sounds like the installer ran one wire from the aquastat to a junction box . Red should go to power , white to the neutral , blue to the circulator and black to the burner . If that all checks out , it might be like I thought - the internal wiring might be crossed . I am talking about the white piece that the aquastat knobs are in - there should be 5 wires going into the front of it - all wired from the factory .

Sento

I forgot to mention with the High at 180 and the low at
140 the water temp is running at 190 - circulator is on.

Thermostat is set at sixty. Room temp is at 68 and rising.

Sento

5 wires

Yes there are five wires coming from the white piece - Going
to different factory set terminals.

Unknown

did you try

disconnecting the thermostat wire altogether ? See if the circ shuts off when you try that .

Unknown

Heres the link

to the schematics of the wiring in these aquastats . Im not sure if itll help or not .

http://hbctechlit.honeywell.com/request.cfm?form=60-2061

Sento

Thanks, I'll check it out.

Glenn Harrison

Triple Aquastat operation as I know it.

I havn't seen a new triple aquastat but all the older ones I have seen operate like this: Low setting controls pump operation, whether or not the t-stat is calling. High setting controls the temp that the burner cuts of at. So, if the t-stat is calling for heat, and the low is at 120­° and the high at 180°, the burner will heat the water to 120° at which point the pump will come on, and the burner will stay on. If the water temp drops below 120° the pump will shut off again and the burner will stay on. when the water temp hits the high limit setting, the burner will shut off but the pump will stay on because the temp is above 120°. When the t-stat is satisfied, the burner will shut off no matter what temp the boiler is at, BUT the pump will continue to run until the water temp gets down to or below 120°, and then shut off. If you are over heating the house, my suggestions are: 1. set the low limit at 140° so pump shuts off sooner, and high limit at 180°. 2. If you have a non electronic thermostat, the anticipator may be set to high causing the burner to stay longer than needed, or it may be set properly for the unit you have but you may need to set it lower to compensate for the triple aquastat pumping heat into the house after the t-stat shuts off. When you look at the honeywell site posted here, the read over the entire install instructions. They should tell you the best way to set the low and high limit, and where the anticipator should be set. You may also want to contact the boiler manufacturer for recomended settings. There is also the posibility that the triple aquastat isnt't original to this boiler, and may have been added to this boiler to prevent another problem. If this is the case , a different approach to the entire install may be needed, but highly unlikely