Boiler/Doorbell Transformer

Has anyone ever heard of, or dealt with, a hydronic, oil burning boiler using the same transformer as the doorbell?

The other day, my doorbell died. I checked in the attic and around the electrical panel for it's transformer but I couldn't find it. The chime would only buzz when the button was pushed. Later, after disassembling and re-assembling the circuit, even the buzzing stopped. At about the same time, the boiler stopped working.
The problem with the boiler was traced to it's 24 volt transformer being dead. That transformer was replaced and the boiler fired immediately. The buzzing also came back when the bell was pushed. It seems that while messing with the doorbell circuit I killed the boiler transformer by mistake. Or is this whole thing a big coincidence?

I had heard that doorbell transformers are usually 16V and boilers 24V but are they sometimes the same and one is used for both systems?

Thanks for any help.

 

The transformer should not be shared. Doorbell transformers are usually 12 volts (I think). It would be worth some investigation. If the two are tied together, separate them.