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12 Cards in this Set
- Front
- Back
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A flue, instantaneous sink water heat which supplies hot water to a tap in an adjoining room is? i Not permitted ii Only permitted when a warning label is attached to the heater that the max continuous usage is 5 mins iii Only permitted when the rated heat inpu does not exceed 12kw net iv only permitted if an atmospheric sensing device is fitted as standard |
A. Not permitted |
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The symptoms of scale formation within the heat exchanger of an instantaneous water heater are? i Increased flow and reduced water temp ii Reduced flow increased water temp iii Reduced flow and reduced water temp iv Dangerously hot water produced |
A. Reduced flow and reduced water temp |
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THe symptoms of dead leg are? i if the pilot goes out when the hot water tap is turned off ii the burner will not ignite when the hot water tap is opened iii the burner remains on for a few seconds after the hot tap is turned off iv Reduced burner pressure |
A. the burner remains on for a few seconds after the hot tap is turned off |
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Select the statement which is correct for modern appliances in the uk i Storage water heaters tend to have a regularly high heat input, instantaneous water heaters tend to have a low heat input ii Storage water heaters tend to have a regularly low heat input, instantaneous water heaters tend to have a high heat input iii Both storage and instantaneous water heaters tend to have high heat inputs iv Both storage and instantaneous water heaters tend to have high low inputs |
A. Storage water heaters tend to have a regularly low heat input, instantaneous water heaters tend to have a high heat input |
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The performance of an instaneous water is defined by i gas consumption measured oven a given period ii Net effiency iii Running cost iv Flow rate and temp rise |
A. Flow rate and temp rise |
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The manufacturers of an instantaneous water heater state hat it can provide 10 litres of water raised by 30°c per minute . If the cold water temp is 7°c and the hot water flow rate has been adjusted to give a temp of 37°c, how long should it take to fill a 1 litre vessel. i 2 secs ii 6 secs iii 10 secs iv 20 secs |
A. 6 secs |
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THe water temp of an instantaneous water heater (flue type b11) will typically be controlled by: i A liquid expansion thermostatic valve ii Throttling the water flow rate or by a thermostat iii A modureg fitted to the gas valve iv A thermistor board sensor |
A. Throttling the water flow rate or by a thermostat |
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The burner pressure of an instantaneous water heater is controlled by? i A pressure regulator ii A fixed or adjustable orifice iii A diaphragm iv Govenor |
A.Govenor |
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Instantaneous water heaters with natural draught flue systems (A11 B11 or C11) tend to have i Bi metallic FSD ii Mercury vapour FSD iii Thermo electric FSD iv Flame rectification FSD |
A. Thermo electric FSD |
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The purpose of the venturi is to? i Generate low pressure when water flows through it ii Increase the gas rate as water flow rate increases iii Create a staged ignition of the main burner iv Ensure rapid closure of the gas valve when the hot water tap is turned off |
A. Generate low pressure when water flows through it |
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11. The purpose of a slow ignition device is to: i Generate low pressure when water flows through it ii Increase the gas rate as water flow rate increases iii Prevent explosive ignition iv Delay closure of the gas valve when the hot tap is turned off |
A. Prevent explosive ignition |
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A storage water heater is intended to be i Left on, full on continuously, the water temp being limited to 100°c ii Left on, full on continuously, the water temp being thermostatically controlled iii Come on and off as hot water tap is opened and closed iv To operate during off peak periods only |
A. Left on, full on continuously, the water temp being thermostatically controlled |
