I've got a snow melt system I'm troubleshooting. It's an Eaton boiler, installed approx 2015/2016. The only information I have is "it hasn't worked the whole time I've been here, which is two years". I'm a new employee to an apartment complex and I have some HVAC/electrical/plumbing background. They don't know what company installed it, warranty info, anything.

So, what I see: one sidewalk sensor, hermetically sealed (in concrete sidewalk). Boiler on wall, control panel on wall, power disconnect, associated plumbing and pumps. Control panel displays correct outdoor temperature and water temp from feed/return (approx 70 outdoor, 77 indoor). There is a fourth temp displayed on control panel at approx 150, not sure what that is (I'm sitting at home right now).

It looks like the installers used 4c 18awg shielded cable for the sensor run. There are two cables headed to (I believe) the sensor. One coming from the control panel, the other coming from the boiler, they are both headed to the same hole in the wall (the system ONLY runs the snow melt). The cable coming off the boiler is using the red and white conductors, the one coming off the control panel is using black and white conductors. From what I can tell, it's wired properly into the system. BUT, they used white on both cables (likely irrelevant, but it confused me for a bit) I used a meter to check continuity, they are not connected. I saw no voltage on the line (yes, system power was on). When I disconnect one lead from the boiler, it starts up but seems to be idling. The pump never turns on. I'm guessing low voltage comes out of the boiler and the Milliamps come back to the control panel. The splice to the sensor wire is buried in either conduit or drywall. I don't see any other connection between the boiler and the control panel so I can't tell what tells the boiler and system pump to turn on.

If any of that made sense at all, any help you can give me would be appreciated. Thanks! We wanna get this fixed before the snow starts coming down.

UPDATE There's nothing wrong with the system. I asked for clarification on what was wrong, they said it didn't heat up. Well, I put it in test mode to get the pump running, shorted the temp sensor on the boiler and had hot water flowing through everything. I tested every sensor for function and every relay. There is nothing wrong with it! I guess we'll find out in a few months when the snow comes!