This is normal for a car. This occurs because the engine has to work a little harder to pump up the heat, and this results in higher RPM.
If you accelerate and the transmission shifts to a lower gear of the overdrive disengages the RPMs will increase. If the vehicle has a manual transmission a slipping clutch will cause the RPMs to increase if the clutch is defective.
No, a water heater cannot explode if it is turned off.
it has a partially clogged heater core.replace the heater core
Yes, at idle it brings the normal stock of 900 up to 1000 rpms
The water heater is turned off to save energy and prevent overheating or potential damage.
The first thing that you need to check will be the coolant level..................
Your car or vehicle is in neutral, or the clutch is shot.
Yes, it is recommended to turn off the water heater when the water is turned off to prevent damage to the heater and save energy.
Yes.
No.
Yes, it is recommended to turn off the gas water heater when the water is turned off to prevent damage to the heater and ensure safety.
The most likely reason would be because you also have the defroster turned on with your heater. The defroster causes the A/C compressor to kick on which helps remove extra moisture in the air keeping your windows from fogging. The A/C compressor is linked to a "kick up" that brings the RPMs up to keep your engine from stalling due to the extra load possibly causing a surge.