- March 14, 2017
Most expansion tanks used today in smaller systems have a pressurized bladder to allow for expansion. Expansion tanks are required on systems such as wells, hot water heaters and heating that recirculate the same fluid over and over. The expansion tank uses an air cushion to allow for the natural expansion of liquids as they rise in temperature to prevent a safety relief valve from activating, or to help maintain pressure to delay a pump from turning on and off as often.
A well system expansion tank should be sized properly depending on the amount of fixtures, people and other uses such as lawn irrigation system. A properly sized expansion tank can provide more constant pressure between cycles, but more importantly it allows your pump to rest between activation’s. It will also provide a longer life span for the well pump and use the least amount of electricity.
The easy sizing method is to count all of the fixtures that use water and choose the size tank needed for the total number of fixtures.
20 gallon = 6 fixtures
30 gallon = 8 fixtures
44 gallon = 14 fixtures
86 gallon = 28 fixtures
3 toilets – 3 lavatories – 1 bathtub – 1 shower – 1 kitchen – 1 dishwasher – 1 laundry tub – 1 washing machine and 2 outside faucets would equal 14 fixtures. Typically you would be OK to use a 44 gallon tank, but you would have no room for adding any plumbing or a lawn irrigation system in the future. Though larger tanks are a bit more costly, we believe you should always go a little bigger rather then hold to the maximum limit. You wouldn’t want to use an 86 gallon tank when your home is sized for a 20 gallon, but going one size larger can be a benefit and will normally pay for it self in time. (Read well switches before deciding on a tank)
The well switch has an on pressure setting and an off pressure setting and controls when your well pump should activate and De-activate. They are normally preset from the factory and available with different pressure settings, such as 30-50 psi, 40-60 psi and 50-70 psi. There are 2 things to point out about these settings and how they may work for your system.
A lower pressure switch less constant pressure to some faucets such as a shower. If you have a 30-50 psi switch it may feel like you have a powerful spray from the shower head after the pump turns off and at full pressure, but when it gets close to reaching the on pressure your spray volume mat be diminished considerably. The extra 10 psi a 40-60 psi switch provides can be a world of difference and feel like you have a completely different system.
Although higher pressure always sounds better, you need to think about your system before adding the highest switch. Your piping system and well pump should play a large roll in deciding which switch to install or replace. If your piping is old galvanized, CPVC or in rough shape from many repairs, we wouldn’t feel comfortable installing a higher pressure switch. If your is in great shape and trustworthy – how is you pump? If you have an old well pump that seems to be one it’s last leg, a higher pressure switch could do it in. A pump has to work a little harder to reach higher pressures. so this does have to be considered when choosing the right switch for your system.
if everything is good to install a higher pressure switch, we rarely see the need for a 50-70 psi switch, a 40-60 is a great in-between, it provide a good constant pressure during pump activation’s and is a little easier on your piping & well pump.
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Note: Carrier Plumbing does not replace or install well pumps, we recommend using a well company for this.