Boiler Locked Out

Blackoakbob

the main power to the unit it sounds like you may have a bad or tripped beaker or blown fuse. Start at the beginning and check the voltage from the breaker to the unit and even trip and reset the breaker anyway just to make sure. Good luck and best regards,

Tom_22

Showing only 12-17V. Boiler wont fire

Any idea how to fix or troubleshoot this?

Boiler won't start. Fan/pump not coming on.

Voltage at pressuretrol and the Honeywell Intermittent Thingy where the T-Stat wire go and the lockout light is only 12V and varying from 12-17V. Previously, when the boiler was working, I measured Voltage at the Pressuretroll to be 120 V.

The lockout light is sometimes coming on but not all the time.

TStat is calling for heat. Water level is OK.

EDIT: I left this out, but it might be pertinant: 1. LEADING UP TO THIS FOR ABOUT A MONTH, BOILER HAS NOT BEEN COMING ON ALL THE TIME WITH CALL FOR HEAT, AND WHEN IT DOES COME ON IT DOESN'T SATISFY T-STAT BEFORE TURNING OFF. A LOT OF TIMES, I'VE BEEN FLIPPING THE POWER SWITCH TO GET IT TO FIRE FOR A WHILE. AGAIN IT USUALLY SHUTS DOWN BEFORE T-STAT IS SATISFIED SO I REPEAT FLIP SWITCH AS REQUIRED. I wonder if all these switch flipping starts has damaged the Honeywell Lockout thingy.

2. AM DOING SOME RENOVATION BUT IT WAS DELAYED AND I HAD DISCONNECTED ABOUT HALF THE RADIATORS IN THE HOUSE (ALL OF UPSTAIRS.) RECENTLY REALIZED 5 OF THE VALVES ARE LEAKING STEAM EVERY TIME THE BOILER COMES ON. THIS HAS PROBABLY BEEN GOING ON ALL WINTER. I wonder if this is why the boiler kept failing to satisfy the T-Stat.

Timco

Have you cleaned your probe? Blown down the LWCO?

Tim

Mitch_6

Voltage at pressuretrol

If you are reading accross the switch it is open. Voltage from each side to ground it is closed. Have you cleaned the pig tail.

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Toddid Goldsmith's

BOILER LOCKED OUT

WHEN YOU CHECK FROM POWER TO "GROUND" YOU CAN GET THE PROPER VOLTAGE. CHECK FROM POWER TO NEUTRAL"NEUTRAL IS GROUND POTENTIAL" NOT GROUND. THE UNIT USES A NEUTRAL WIRE, BACK TO GROUND, AT THE POWER ENTRANCE. MAKE SURE YOU HAVE A GOOD NEUTRAL PATH TO GROUND. MACDONALD MILLER LOW WATER CUT OFF'S HAVE A TWO POSITON ROCKER SWITCH, WHEN BAD, CAN GIVE YOU SOME WIERD VOLTAGE NUMBERS. CHECK THAT NEUTRAL. GOOD LUCK.

Tom_22

It's got power

It's got power at the boiler. Breaker and fuse are OK. Emergency Off switch is powered on. On/Off switch at boiler is on.

Tom_22

12V seems wrong whether Pressuretroll open or closed

Hi Mitch,
I took readings from both sides of the pressuretroll switch to ground. The switch can visually be seen to be closed (the mercury tube is fully tilted.) This is as expected as the boiler is cold and has no pressure in the boiler.

But I don't understand why I'm reading 12-17 V. It should be 120V, no?

If I open the switch by hand (manually tilt the mercury switch open) I get voltage on the in side but 0 Volts on the output side to ground or across the switch. If I was getting any voltage across the switch when it was open I would think there was something wrong with the switch. No?

Pigtail: I cleaned it a couple of months ago. It was very clogged and leading up to the cleaning I found myself increasing the pressure setting on the pressuretroll to get the heat to come and stay on. I didn't clean it again and I don't know if it needs it, but I don't think that would have anything to do with the burner not firing/fan coming on.

Tom_22

Whats the probe? LWCO blown down

Hi Timco,

I did blow down the Low Water Cut Off.

What is the probe? If you mean the pressuretroll pigtail, I talked about that above in response to Mitch.

Tom_22

Problem Solved. It was the Primary

It was the Primary. My oil supplier serviceman changed it for me. I had a feeling it was that, but wasn't sure. How do you troubleshoot those anyway?