State Industries SBD71 120 General Questions And Answers, Sbd Tank Type Heaters, Service Handbook

SBD TANK TYPE HEATERS

SERVICE HANDBOOK

GENERAL QUESTIONS AND ANSWERS

Q.What is unique about the Canadian – SBC-CGA – models vs. U.S. SBD models?

A. The Canadian models have different dimensions to meet Canadian code requirements.

Q:How much electrical power is required for a SBD water heater?

A:The SBD models draw approximately .7 Amps at 120VAC.

Q:The units require "leg kits" to meet National Sanitation Foundation standards.

Q:When should SBDs be delimed? NOTE: The “Hydrocannon” should eliminate or greatly reduce the lime build up rate from the water heater.

Many variables affect the liming up process including:

water temperature - The amount of lime precipitation during the same period of time will be nearly 2 times greater if water is stored at 140 degrees F than at 120 degrees F. A 180 degree setting will precipitate lime about seven times as fast as a 140 degree F setting. volume of water - The more gallons flowing through the SBD, the more exposure to accumulation.

hardness – The harder the water the higher the possibility of lime build up. 1 to 3.5 grains per gallon is "soft", 3.5 to 7 grains per gallon is "moderate", 7 to 10.5 grains per gallon is "hard" and 10.5 + grains per gallon is "very hard". (An aspirin is about 5 grains. One grain is equal to 17.1 parts per million.)

A:Deliming should be done when a slight rumbling or popping sound is detected when the main burners are on.

Q:What effect will lime build-up have on the SBD water heater?

A:One eighth inch of scale build-up may reduce efficiency as much as 22%; a 1/4 inch build- up, as much as 38%.

A:Less efficient heat transfer means more bottom head expansion/contraction stress and

premature leakage.

A:Heavy build-up on the bottom head and bottom portion of the flue pipes leads to more heat

transfer at the top of the flues. This can lead to stacking or erratic thermostat operation.

A:The “Hydrocannon” greatly reducesthe possibility of lime build-up.

Q:Anode rods provide additional protection against corrosion. When should these be replaced?

A:When large gouges or pits appear in the anodes, replace them. It is recommended that these be inspected every 6 months.

Technical Training Department	42
Ashland City, TN ©2003