I can understand how the pilot keeps the boiler warm even in cold weather, but what protection has the water tank against freezing?
The products of combustion from boiler and burner, when standing, are delivered directly against the water tank, which helps it to retain its warmth. Furthermore, after the car has run even a short distance, the water in the tank is warm from the exhaust steam and will resist the cold while standing for a, long time. This is quite enough except in severely cold weather when the car has been left exposed for several hours. Then, some ice may form in the tank.
