Boiler Update

The weather has been especially fickle as of late. After my initial test firing of the boiler it promptly got warm again and stayed that way for a couple of weeks. When it got colder again, I went to fire up the boiler. Since it worked fine the first time, I didn’t anticipate any problems. Unfortunately, the initial success was not reproducible. I suspected the gas control knob since it had been –shall we say– sticky. In order to find out I had to get a multimeter so I could trace back the electrical connections.

Things seemed to be good. I was getting current, though it seemed a bit erratic, and there wasn’t a clear reason that the burner wouldn’t light. I redo all of the wiring because it was a mess, with old cracked wire and lots of places that could be shorting. Even so, nothing was working. A few days went by and I was running out of things to check and the house was getting cold. Then, Sarah sends me a video while I’m at work.

I ask her to disconnect the thermostat and when I get home I can no longer get any signal from the transformer. So I ordered a new transformer. The house gets colder and colder until we can see our breath while watching TV. Have I mentioned there’s no insulation in this house? Despite paying for rush shipping, the part takes almost a week to arrive.

I install the new transformer and sure enough, the weather suddenly gets warm and then hot. With it eighty degrees in the house, I can’t easily test the system, so I move on to other things. Then this past week, it starts to get cold again. I flipped the switch on the thermostat, went downstairs… and nothing was happening. Incidentally, somewhere in this process I learned that the system is steam, not hot water, so while there is a cold water feeder, it isn’t powered. Everything just runs low voltage.

I break out the multimeter again and test voltage at each connection. Nothing. No juice at all, even out of the new transformer. I test the power coming into the transformer, and the line tester beeps affirmative. It doesn’t make sense. I test resistance between the terminals of the transformer and confirm it isn’t shorted. Finally, I disconnect the new transformer to inspect it and make sure I’m not missing something. Everything looks fine.

Unsure what else to try, I hook the transformer back up. I’m not sure what I did differently, but this time the transformer was live. I connected the wires, testing at each point with the multimeter. Signal is getting through the pressure cutoff, but when it gets to the low water cutoff switch, it stops. It’s in alarm state. The strange thing is that I know the low water cutoff works. If I drain water from the system, it fills it back up. There seems to be a problem with the mechanism that connects the switch to the actual water feeder. According to the documentation, it could be several things, with different parts to replace. Since I know the low water feed is working, I take the chance and simply bypass the switch.

The last stop for the wire is the gas control valve. I turn off the thermostat and reconnect the valve. I relight the pilot. I run back upstairs and switch on the thermostat. As I come back down the stairs I can hear it: the boiler is firing. Finally.

Sarah and I went back upstairs and watched tv. In about half an hour we started hearing noises from the radiators. They started getting warm. They hissed a little. The pipes banged. Most importantly, the house got warm. I checked pressure, made sure it shut off when it reached the right temperature, and it’s continued to work beautifully –if noisily– the last few days. It just needs to make it through this winter. Next year we’ll start work on our massive HVAC undertaking. For now, we have heat. All it cost me was time and about twelve dollars for the transformer.