I have never had a boiler run dry when using hot water compared to warm or cold water. As stated in my article in issue 69 of SitG, the difference in volume between water at or near freezing and water at or near boiling is not significant enough to report. On a 100mL sample the volume difference is less than 5mL. Also, if you start with 200mL of water at 90 degrees Celsius or 200mL of water at 20 degrees Celsius, you still are staring with 200mL. I am being told by a reader that he is sure using hot water will cause the boiler to run out of water faster. I have NEVER had that happen and for all intents and purposes have NEVER noticed a bit of difference. Have any of you?
I think we may be talking of two different things here. What is being suggested, I think is, that if you start with hot water it will boil and turn to steam much faster than if you start with cold water. It is then possible to use up all your water before the fuel runs out - we're talking about a loco here that doesn't have a fill valve on it.
regards,
pf
