Oil furnace. No power

hubbyho

Hi guys.
I woke up to no hot water. I have a multi zone oil furnace with power to the controller and low water cutoff but no power to the aquastat or burner. Any suggestions as to why the aquastat wouldnt have 120v?

HVACNUT

Does power go from the LWCO directly to the aquastat? Is there power on the load side of the LWCO? Are you testing with a meter or just seeing status lights?

hubbyho

Thx HVacNut.
Im seeing the lights on the Lwco but metering others. 110v (measured it) comes in and splices, one to the lwco and the otherbto the aquastat. Measuring L1and L2 of the aquastat has no voltage. I dont understand that. I have 0v at the TT 24v connection which i think is correct when calling for heat.
I double checked the burner and i do have 110v at the pigtail but no lights on the primary ignition controller.
Still stumped

Noel

Are you measuring to neutral or to ground? An interruption on the neutral side can be tricky to find.

Paul48

Turn the emergency switch back on.

Jamie Hall

Keep in mind that if the aquastat is calling for heat, you will have the same voltage on both sides. Also, not sure what you mean by the 110 coming in and splices? If all the controls are 110 except the thermostat, then they should all be on the hot side...

HVACNUT

It's likely the LWCO has failed, or the sensor needs to be cleaned. What model LWCO, and can you post a pic of its internal wiring? (Turn off power first)
Ok, wait, you DO have 110v at the primary? Then you should have 110v at B1,B2 on the aquastat unless the primary has seperate L1 and Limit terminals and powered independently.

hubbyho

I have a safegard 1150 lwco and honeywell aquastat....

hubbyho

Doesnt seem to want to upload pics.
To clarify for jamie, the hot comes in and is spliced to a red and black wire. Red feeds the lwco, the black to the burner.
Does the lwco provide power to the aquastat?

hubbyho

Ive got three wires coming in to the lwco, neutral red n black. The black wire goes to the aquastat, red should be 110v and white neutral. Can i connect the red 110 tobthe black going tonthe aquastat to see if it powers on?? That would isolate the lwco as the culprit, no?

hubbyho

Lwco

Paul48

Don't change any connections without figuring out the wiring. Usually, doing so, is followed by a poof, and that's the sound of money being burned.

Paul48

http://s3.supplyhouse.com/product_files/Safgard-1150-install.pdf

Paul48

Find the instruction for whichever Aquastat you have also. It will have in internal schematic.

hubbyho

Thanks to everyone, especially HVACnut. I graduated a 900hr HVAC course in the early 90s and never put it to work in the field. I have enough confidence to tear into things but then find myself second guessing, relying on forums like this to get me to solutions. Thank you for the warnings and the push!
Turned out to be the lwco which i replaced in 2009. Thats not very good life expectancy! But thanks again for all your input!!!

newagedawn

wow, someone actually came back to say thanks, impressive!!!