Gas heated shower going hot and cold?

[slogger]

We have four showers that are gas heated and have a high pressure pump and pressured water tank. There is enough pressure to run four showers at the same time with sufficient hot water (since I installed water saving shower heads), when one of us showers at first it really good (very high pressure) and then you can hear the water pump kick in and too much hot water comes through so you have to turn the hot tap down and or increase the cold flow, then sometimes it will go completely cold as by increasing the cold tap the heater will turn off. I will then have to turn off the hot tap and turn it on again, and can hear the gas heater relight.
What are some possible causes and solutions of this problem. My thoughts are maybe the pump is turning on too frequently (about every 3-4 minutes) due to a waterlogged tank, and needs draining, or the min/max pressure settings need adjusting (pump turns on at 25psi, turns off at 50psi), or some other problem? thanks

 

[leftheart]

I have an inline water heater and it is all about constant water flow and how much is flowing. If it drops to low then the heater cycles on and off. try turning on another sink when you are showering or what ever else is hooked to the same system... sometimes I need to allow more water to run through the system to tell the water heater to stay on..