Do pilot switches go bad?

guzzinerd

Today I had a technician come out and test the natural gas pressure at the boiler (3.5). It took a few minutes to get the pilot lit again but it finally lit and we left.

A few hours later i get a call from a tenant that the indoor temp is down to 61 so I go over (thermostat is set to 69). I had a spare pilot switch so i swapped it out and the thing fired up again.

Should i be changing the thermocouple as well?

Before heading home i shut it down with the LWCO and started it up again when i shut the valve.

Thanks . This is the first time the boiler failed to fire up so was a little stressed out. It's cold.

mattmia2

Thermocouples wear out over time and produce less and less current. you can get some idea about the condition with a millivoltmeter and some other tests that are in the instructions. The coil can break or I think there is a permanent magnet in the baso switch that can get weak but it is much more likely the thermocouple wears out or something happens with the pilot burner or the placement of the thermocouple in the pilot flame such that it doesn't get heated enough. A leaking boiler or condensation or any number of other leaks can put it out too.

guzzinerd

Thanks. It super dry out here and there's no moisture or condensation anywhere in the building.

I have a spare thermocouple as well, that something I can change myself or do I need a pro?