To repair a Delta Monitor shower, you must first identify the specific problem. Common problems with Delta Monitor showers include the pressure balance valve not working properly, leaking under the handle, and water coming out of the shower head and spout at the same time.
If the Monitor pressure balance valve is not working properly, check the spool and sleeve for contamination. Begin by removing the handle if you have series 1300 or 1400. Remove the temperature knob, cover and handle if you have series 1700 or 1800. Twist and pull the sleeve to remove it before unscrewing the brass bonnet nut and removing the cartridge. Soak the cartridge in a vinegar and water solution for 24 hours, and replace the parts. Carry out periodic inspection of the pressure balance valve if the water in your area has lime or other contaminants.
The most common reason for leaking under the handle is a loose adjusting ring. Tighten the loose adjusting ring, but if the problem persists, check the ball valve installed. Replace a vacuum breaker ball with a non-vacuum breaker ball. A vacuum breaker ball features two vent holes in the top of it.
If water cannot get out of the spout as fast as it flows through the valve, water backs up and comes out through the shower head as well. This could be due to a valve that is upside down, inappropriate length between the valve and the tub spout, or something lodged in the pipe restricting water flow. Use a plumber’s snake to remove the blockage, or seek the help of a plumber.