Originally posted by wendel
A friend has decided, due to warming temperatures, to reduct the gas flow to 80% of normal by partially closing the main shutoff valve. He has a natural draft furnace and says the flame is about 3/4 the height when the main gas valve is fully opened. The furnace now works perfectly with the gas flow reduction, other than a longer cycle time, which was his goal.

What dangers has he overlooked?
Thank you for offers in the department of job security! Your buddy is only causing future problems. If a little does a little good then a lot does a lot of good, if he wan'ts to save on his gas bill tell him to shut off at the meter! Every thing that you fiddle with, if you don't know what is really going on, makes other people money! If the temps are warming he can cut back at the thermostat and leave well enough alone. This would be funny if it wasn't for the botched suicide train derailment in california...how many people does your friend intend to take with him?