I've installed a new Potable water pump and now my shower runs from hot to warm/cold. The new pump is slightly higher GPM than the one I replaced and I have an accumulator tank.
I pumped up the accumulator tank (first time in 17 years) and the temperature variances didn't go away. I didn't go with the newer style Sensor pump because I didn't want to alter - remove accumulator tank - as my spares were old style that uses accumulator tank.
Any Ideas appreciated.
Perhaps look for any 'mixing' opportunities inline with the hot and cold water. Let me supply some examples that may make sense -
--You may have a swim platform shower, it may have hot and cold in the device. There may be a way to leave the shower itself off but have each hot and cold faucet open allowing one to flow into the other but not out of the faucet. This will show up down line as your shower is running.
--You may have a device like this in your shower that you temporarily turn off at the spigot to conserve water.
--You may have a heater bypass installed that is partaily open (or closed as the case may be).
Most of these are likely easy to remedy by leaving the devices all off and/or by adding a one way valve in the hot water line in the appropriate location. Switching from shore water to boat water adds confusion when trying to solve for these problems.
Hope this helps.
The actual flow of the hot or cold water is dependent of the pressure and the pressure/flow variation, due to the differences in plumbing, is different. Your old pump was probably running continuously while the shower was running. Your new, improved pump now cycles and the pressure ranges from shut off pressure to switch on pressure.
Just because the Sensormax type pump doesn't REQUIRE a buffer tank doesn't mean that you can't leave the old one in the system.
My shower acted similar to yours. Some days I needed all the hot and a little cold. The next day all the cold and a little hot. I thought it was probably water pressure variances from the shore water supply. Taps were finished so I installed a new set. Made no difference to the water temp problem. Water heater was leaking so I changed it and in the process, replaced the defective check valve on the cold water side of the water heater. The problem is gone and I think it may be related to the check valve but I'm not sure I understand why.
I had the same problem after I replaced my defective pump with a new, better, higher volume pump. Where the old pump ran continuously and provided a constant smooth stream of water the new pump cycled on and off causing the shower to cycle between too hot and too cold. It was really annoying.
I replaced the new pump with a Sensormax and the problem went away. It also eliminated the pump turn on / turn off noise. Great pump.