Originally Posted by sailorchic34
The accumulator can be on the cold side too, Btw even though the new vsd pumps don't need it, its really good to have to keep the pressures in the water lines under control when the water heater goes from cold to hot. Its actually a pretty big problem on boats. By building code its required on all new building construction, Least wise in the UPC, think BOCA too. (building codes)-ish
I use a bigger 2 gallon residential thermal expansion tank available at the big box stores rather then the little jabsco tanks at the marine
VSD pumps don't need it for maintaining pressure, but water systems need accumulator tanks for compensating for water expansion as the water heats.
I agree...when we replaced our 4 liter accumulator (expansion) tank which was located near the hot water heater, we bought the new tank from a "well water shop," and increased it to a 9 liter...much better. It is important to properly adjust the pressure on the air side of the accumulator tank. If you are not sure what to adjust it for, 40psi should work for most boats.
The reason I like to suggest placement on the hot water side, is it is best to place the accumulator as close to the source of increased pressure as possible...that way, you are not exposing more feet of hose to the source of the pressure increase. I find that most accumulator tanks used to assist the water pump in maintaining constant pressure are placed near the pump. For a typical yacht of less than 18m, I recommend one 4 liter accumulator near the pump and one 9 liter near the hot water heater.
Oh, one more thing, I suspect the root cause of commonly experienced leaks near/around the heating
element seal are caused by increased pressure in the hot water heater.