I am looking after a house that has a model 230WG Bryant gas boiler. It may have a millivolt system as it is quite old. The pilot light is out. I can get the pilot light to start by holding the "set" lever, but as soon as I release it, the pilot light goes out. The owner of the house is recently deceased. I know the furnace worked last winter.

I am looking after a house that has a model 230WG Bryant gas boiler. It may have a millivolt system as it is quite old. The pilot light is out. I can get the pilot light to start by holding the "set" lever, but as soon as I release it, the pilot light goes out. The owner of the house is recently deceased. I know the furnace worked last winter.

It very well could be the milivolt generator that the pilot light is attached to. I always test them before replacing but you would need the proper meter. If you are looking after a house it might be your best bet to call a lock HVAC contractor so you do not take a chance of freeze damage.