Question

which of the following statements about electric water heaters is not true? 4 500 watts is roughly equivalent to 15 000 btus per hour they usually have a larger storage capacity than gas or oil tanks they have a slow recovery rate they sometimes have an energy cut - out and pressure relief valve they do not require a sacrificial anode question 8 circulating hot water systems are required on all new installations eliminate the wait for hot water after long or idle periods require no additional piping have a pump that comes on every time water flows through the hot water system should never have a check valve in the system because that may obstruct the flow

Explanation:

1. For the first question about electric - water heaters:

• 1 watt is approximately 3.412 BTUs per hour. So, 4500 watts * 3.412 = 15354 BTUs per hour, so the first statement is roughly true.
• Electric water heaters usually have a smaller storage capacity than gas or oil tanks, making the second statement false.
• Electric water heaters often have a slow recovery rate compared to some gas - fired units, so the third statement is true.
• They can have an energy cut - out and pressure relief valve for safety, so the fourth statement is true.
• Electric water heaters do not require a sacrificial anode like some metal - tanked gas water heaters, so the fifth statement is true.

1. For the second question about circulating hot - water systems:

• They are not required on all new installations, so the first statement is false.
• They are designed to eliminate the wait for hot water after long or idle periods by keeping the water warm in the pipes, so the second statement is true.
• They usually require additional piping for the circulation loop, so the third statement is false.
• The pump in a circulating hot - water system does not come on every time water flows through the hot - water system; it operates on a timer or a sensor - based system, so the fourth statement is false.
• A check valve is often used in a circulating hot - water system to prevent back - flow, so the fifth statement is false.

Answer:

Question 7: they usually have a larger storage capacity than gas or oil tanks
Question 8: eliminate the wait for hot water after long or idle periods