[George]

Jimmy , Did You check the air pressure in the tank ?

[AL]

The new accumulator tank has 25 lbs of pressure. Manual says it comes with 20 lbs of pressure which is the most common.

[Rodney]

Accumulator tank pressure is dependent upon the water pump cut in pressure.

Typically the accumulator should be about 2 PSI less than the water pump cut in pressure. To set pressure turn off pump, run the water until there is zero pressure, leave a valve open and pressurize the accumulator to the desired pressure.

Close the valve and turn on the pump.

[Archived]

Thank you for this thread, and Rocky and Jon’s responses. My pump was kicking on after just a couple of seconds of water flow. I had a feeling that wasn’t right, but hadn’t started looking into it. After reading this I went below with a faucet running and saw that the pressure was swinging wildly between about 18 and 40 PSI as the pump cycled on and off. I followed Jon’s instructions and brought the tank up to about 16 PSI. Now a faucet will run for about 20 seconds before the pump kicks on, and the water pressure is stronger. I see that my Pumptrol pressure switch is adjustable. Are there some changes I can make with that and the accumulator pressure to improve things further? The copper plumbing is pretty robust, but I don’t know what the safe limits are.

[Will]

Water pressure should be set to accommodate the needs.

Certain water system components and features require pressures around 60 PSI such as Headhunter toilets and RO water systems. If the system does not demand the higher pressures 40 PSI is probably OK.

The pressure switches are typically well pump switches and they are adjustable for both cut in and cut out pressure as well as the differential. A typical differential is about 20 PSI but on some pump switches it can be adjusted.

The accumulator tank has an air bladder that will smooth out the pump operation and some pumps such as the Shurflo or some models of the Headhunter pump do not require an accumulator tank. On systems designed to use an accumulator tank if the tank pressure is set too low or if it has no pressure the water pump will cycle on almost instantly and will go on and off with any use of water.

[Towson]

My pump was back to cycling after a few seconds this morning, so I checked the tank pressure and determined that the bladder inside must be bad. $55 for a new 4.4 gal tank at Menard’s and about an hour to do the swap. A lot of that time was letting the tank slowly drain before unscrewing it the final few turns, all to avoid a wet mess in the bay. That worked. I bled the precharged tank from 40psi to 18 psi, and left the pump controls at roughly 20psi/40psi. Now I can run the galley faucet wide open for nearly two minutes before the pump kicks on, and the pump runs for almost a minute to rebuild pressure. No more pressure variations, either. The new tank mercifully fit the old mounting ring. Thanks to all for helping me enhance my enjoyment of the bus!