Question

a pressure switch on a power vented water heater
operates the blower if air pressure is too high
operates the blower if air pressure is too low
provides adequate combustion air
senses excess water pressure in the system
verifies that the blower has started
question 24
which of the following is not a problem with water heaters?
the baffle or turbulator is missing on a gas or oil fired water heater
there is no isolating valve on the cold water inlet
the tank is leaking
there is no isolating valve on the hot water outlet
the hot and cold water piping are reversed

Explanation:

For the first question, the pressure - switch on a power - vented water heater verifies that the blower has started. It's not about operating the blower based on air pressure levels or providing combustion air or sensing water pressure. For the second question, having the hot and cold water piping reversed is not typically considered a problem with the water heater itself but rather an installation issue. The other options are problems related to the water heater's components or connections.

Answer:

First question: verifies that the blower has started
Second question: the hot and cold water piping are reversed