why my new bathroom mixer valve have very low water flow?


I have bought the Italiano square thermostatic 3 way mixer diverter (B013), and I have recently installed it, I realized that the water flow is too slow coming out of it, I have a water pressure pump, but because of the slow water flow, it doesn’t keep the pump running constantly! is there any solution for this, please help!

I installed a bathroom on a second floor. A pressure pump was in the basement. Risers to the bathroom were all 3/4" and 3/4" was plumbed directly to the tub mixing valve. The shower had a mixing valve, a separate diverter valve that went to a hand held hose and a fixed shower head. Plumbing lines had to be bushed down to 1/2" to enter the mixing valve.

The tub has a lot of flow and always works great. The shower has never worked well due to too little flow. Even after a new regulator on the pump pushes pressure up to 70/55 psi (cut off/ cut in) There is too much resistance in mixing valve and too little flow into the mixing valve. The solution and yours is to re plumb it using a mixing valve that will accept 3/4" lines coming in. The problem is insufficient flow (amount of water) and not pressure.

Thermostatic shower not getting hot water?

One Response to “why my new bathroom mixer valve have very low water flow?”

  • Breath on the Wind says:

    I installed a bathroom on a second floor. A pressure pump was in the basement. Risers to the bathroom were all 3/4" and 3/4" was plumbed directly to the tub mixing valve. The shower had a mixing valve, a separate diverter valve that went to a hand held hose and a fixed shower head. Plumbing lines had to be bushed down to 1/2" to enter the mixing valve.

    The tub has a lot of flow and always works great. The shower has never worked well due to too little flow. Even after a new regulator on the pump pushes pressure up to 70/55 psi (cut off/ cut in) There is too much resistance in mixing valve and too little flow into the mixing valve. The solution and yours is to re plumb it using a mixing valve that will accept 3/4" lines coming in. The problem is insufficient flow (amount of water) and not pressure.
    References :

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